tesla turbine technicals

Articles

Phoenix Turbine Builders ClubTable of Contents

NEW Articles:First Quarter 2006 Report: Breaking the Yoke of Dependence, more on the CAD CD, Tesla Turbine oiling system details - Ken Rieli

2001 ArticlesJanuary 1, 2001 January 10, 2001 February 1, 2001 March 5, 2001 April 2, 2001 May 2, 2001 June 18, 2001 July 9, 2001 August 27, 2001 September 10, 2001 September 11, 2001 October 22, 2001 November 27, 2001

Forward Introduction -- Ken Rieli, Founder Engine Case Selection Bearings Shaft Basics, and Pulling It All Together How to Build & Assemble Remaining Shaft Components Fitting Parts Together in the Real World, Introduction to the Hot Rotor Hot Rotor Case, Lubrication & Energetic Fluids Member Input: Pulse Combustion Project by a Tesla Turbine Enthusiast! Member Input: From California: A Member's Tesla Turbine Generator Project Member Input: More from Luis Mendonca: Pulse Combustion Update on the Phoenix Turbine Builders Club Tesla Turbine Project! Combustor Improvements, Nozzle Construction & More Test Results

http://phoenixnavigation.com/ptbc/toc.htm (1 of 6)6/10/2006 8:38:37 PM

Articles

December 24, 2001

Combustor Test Results, More on Nozzles & Combustor Sequencer Schematics Member Input -- Luis Mendonca's Pulse Combustion Turbine, and Samuel Falvo's Paper Turbine

2002 ArticlesJanuary 23, 2002 February 26, 2002 March 27, 2002

New Directions in Turbine Design Fuels Solutions Special Test: Tesla Disk Design Vs. Phoenix Hybrid Winglet Design, More on Inlet Nozzles Turbine Construction Details, Beyond Tesla, Our Comparative Tests Member Input: Samuel Falvo Performance Report, and Hamish Edgar on Tesla Disk Spacing

April 29, 2002

September 25, 2002 September 27, 2002

Member Input: John Faith's Compressed Air Turbine Project Combustion Models -- Getting the Most Bang for the Fuel Buck! Also: Pulse Combustor Wiring Diagram Correction Dynamics of Disk Spacing, Geometry, Horsepower & Torque Member Input: Richard Gideon's Experiments in Disc Geometry Improvements Also: 2002 End of the Year Review by Ken Rieli

December 5, 2002

2003 ArticlesJanuary 8, 2003

Worldwide Proliferation of Tesla Turbines -- "Build-to-Order Tesla Turbine Kits" and "Using Tesla's Turbine to Generate Electricity and Income" Developer of the Month! Richard Gideon's Continuing Experiments in Disk Geometry Improvements First Detailed View of the Global Cogenerator Turbine Developer of the Month! Nozzle Experiments by Richard Gideon Experimenter's Turbine Launch Chapter 1 Experimenter's Tesla Turbine Assembly Manual: Bearing, Oil Pump Case Chapter 2 Experimenter's Tesla Turbine Assembly Manual: Shaft Assembly Developer of the Month! More on Nozzles, Experiments by Richard Gideon

January 8, 2003

February 11, 2003 March 1, 2003 March 18, 2003 April 22, 2003 May 31, 2003 May 2003


Articles

June 4, 2003

Chapter 2 (continued) Experimenter's Tesla Turbine Assembly Manual: Final Shaft Assembly Chapter 3 Experimenter's Tesla Turbine Assembly Manual: Hot Section Developer of the Month! Sean Doyle's AOL CD Tesla Turbine Project Time to Get Off the Grid! by Ken Rieli Chapter 4 Experimenter's Tesla Turbine Assembly Manual: Jet Oil System Understanding Turbine Basics -- Impulse turbines, reaction turbines, Tesla disk turbines Nozzle Design, Key to Turbine Efficiency -- Inlet nozzle, disk geometry, outlet nozzle Boiler Basics: Waste Oil Generator System -- Chest boilers, flash tube boilers, boiler operation Completing the Waste Oil Generator -- System description by Ken Rieli

July 11, 2003 August 1, 2003 August 20, 2003 August 20, 2003 September 2003

October 2003 November 2003

December 17, 2003

2004 ArticlesJanuary 27, 2004 February 25, 2004

2004 Free Energy Plan -- Solar steam turbo-electric generator system by Ken Rieli Solar Steam Turbine -- Examining the Curnutt solar furnace, construction basics, solar tracking by Ken Rieli Parabolic Reflector Basics -- How to design plugs for constructing a precise FRP solar reflecting dish by Ken Rieli Developer of the Month! Solid Fueled Flash Boiler Experiments -- Steve Redmond Solar Reflector Dish Mold: Shaping the Plug -- using a low-cost plywood template to shape sand & concrete by Ken Rieli Constructing the Fiberglass Solar Reflector Dish -- fabrics, resins, parting wax, FRP layup tips, and how to pop the dish from the mold by Ken Rieli Hanging the Dish on the Steel Mount -- stiffening techniques, sandwich construction vs. steel rib supports by Ken Rieli Solar Turbo-generator: Anatomy of a Two-axis Mount -- azimuth & elevation, tracking the sun's path to focus maximum solar heat energy by Ken Rieli Developer of the Month! Curnutt Style Furnace Project by Sean Capogreco Waste Heat to Electricity Tesla Turbine Project -- Ken's new custom designed turbine built for SVSU experiments using CFC refrigerant New 6-inch Turbine for Low Horsepower Applications! - Ken's closed loop solar turbine design; designing for load, energy transfer efficiencies, turbine sizing, storage options, containment vessel & more

March 18, 2004

March 2004 April 2004

May 2004

June 2004

July 2004

July 2004 August 2004

September 2004


Articles

October 2004

Opposed Bearings & Stacked Plate Turbine Design - advantages of opposed bearings & overhung rotor designs; also stacked plate construction, by Ken Rieli Parabolic Trough to Produce Steam, Thermocouple Electricity - easy to build solar reflector for efficient energy transfer; direct heat to electricity using thermocouple effect by Ken Rieli Developer of the Month! Curnutt Furnace Update: Free Steam, Winter Heat by Sean Capogreco 2004 Review: Solar Turbo-generator Basics through New Turbine Designs by Ken Rieli

November 2004

Oct-Nov 2004

December 2004

2005 ArticlesJanuary 2005

2005 Looking Ahead at Complete Solar Systems Development, New Experimenters Tesla Turbine by Ken Rieli Introduction to Electronic Systems Development -- low-cost, easy to use developer's systems; front end computers, developer software & embedded processors for solar energy projects by Ken Rieli Developer of the Month! Fire from Ice! Sean Capogreco's Curnutt Furnace Project Solar Dish Aiming & Tracking System - Electronic System Block Diagram - aiming and tracking system overview, and how it relates to the system development hardware by Ken Rieli Targeting Subsystem: General Purpose Microcontroller for Intelligent Solar Tracking how discreet electronic components interact with the embedded processor by Ken Rieli Developer of the Month! Schematic for Solar Collector Sun Tracking - Richard Gideon shares solar technology More on the Embedded Microprocessor Solar Targeting System - how to connect LDR & phototransistor light sensors to the cpu by Ken Rieli New Life for an Old Engine Case - using a recycled engine case for a small turbine by Ken Rieli The New 4.5-inch Turbine Initiative - introducing our new 4.5-inch Experimenter's Tesla Turbine Hot Rotor Kit! by Ken Rieli Developer of the Month! Luis Mendonca's PDE Project

February 2005

February 2005 March 2005

April 2005

April 2005

May 2005

June 2005

Introduction to Solar Systems Programming - essential flowcharts, adding intelligence to an actuator power control unit for solar tracking by Ken Rieli New Life for Old Engine Case 2 - bearing plugs, air galleys, shaft preparation & case assembly by Ken Rieli


Articles

July 2005

Solar Targeting: translating the flowchart into lines of software - sending data in one direction over a two-wire cable from PIC processor to PC by Ken Rieli More Programming Basics: examining a simple terminal program - receiving status values sent by the PIC processor to a PC; printing to a computer screen by Ken Rieli It's Alive! It's Alive! - wiring the dish & commanding it to move; equations & computer program for aiming the dish based on predicted solar position New 4.5" Experimenter's Tesla Turbine, construction details Part 1 - baseplate, bearing housing end plates, hot rotor housing, case ring by Ken Rieli New 4.5" Experimenter's Tesla Turbine, construction details Part 2 - exhaust port, fittings, new experimental air seal design, bearings, new dry sump system design by Ken Rieli 2005 Review- Moving on to Phase II - from basic technology & component builds to application

August 2005

September 2005

October 2005

November 2005

December 2005

2006January 2006

Strategy for 2006 - energy independence, Experimenter's Tesla Turbine applications, new energy Open House - Ken Rieli Rebirth of the Tesla Turbine.pdf - 2003 Extraordinary Technology reprint, by Ken Rieli Tesla Turbine Primer.pdf - 2003 Extraordinary Technology reprint, by Ken Rieli

February 2006

Jan - Mar 2006

First Quarter 2006 Report: Breaking the Yoke of Dependence; CAD CD; Tesla Turbine oiling system details

Check out our Forum Archives for more information!Phoenix Turbine Builders Club, Nikola Tesla, bladeless turbine, disk, disc, 21st century transportation, motive power revolution, turbines for hybrid vehicles, direct drive, automotive turbines, aircraft turbines, vehicles, turbine engine, hybrid locomotive engines, sustainable energy, solar turbogenerator, electrical generators, distributed power, microturbine, microturbines, electricity, electric grid, unplug, co-generation, renewable fuels, renewables, solar, biomass, fuel crops, ethanol, methanol, alcohol, biodiesel, crop residues, forest residues, closed loop steam, hot gas, combustion, catalytic, pyrocatalytic, recyclable fuels, recycled waste oils, used motor oil, restaurant, grease, solvents, air pollution, pollutant emissions, diesel exhaust, particulate matter, particulates, environment, sustainable development, sustainability, NGO, global warming, environmentally sensitive technologies, clean energy, ozone, green energy, greenhouse gases, homeland security, energy security, fuel efficiency, carbon dioxide, CO2, carbon monoxide, CO, sulphur dioxide, nitrogen oxides, ban the piston engine campaign, enabling technologies, environmental remediation, Ken Rieli

Last updated: May 25, 2006 12:59 PM


Articles

Phoenix Turbine Builders ClubFREE Open Source Forum http://phoenixnavigation.com/ptbc/home.htm


Forward, Phoenix Turbine Builders Club, build a low cost Tesla turbine to reduce pollution hosted by Global Motive Power Revolution

Phoenix Turbine Builders Club

ForwardThis is January 1, 2001 -- the beginning of a new century and a new millennium. It is appropriate that we start out the 21st century with new technologies that will enable people across the world to take an active part in changing the future. If there is one thing that we learned from the 20th century, it's that greed economics -- the basis of all capitalism -- does not work and will end up in the boat with failed communism. Uncontrolled consumption of inexpensive fuels enabled the rapid growth of the U.S. economy for the last 100 years. During that time we have used more than half the world's available fossil fuel without making a better way of life for the greater part of the human race. Developing countries are attempting to duplicate the success of their U.S. mentor, but a key ingredient is missing: cheap fuel. We no longer have "boundless" supplies of fuel. The fact is, there is no more cheap fuel! Within a few short years, global oil production will peak and will begin a steady disparity between oil needs & oil supplies. America's success cannot be duplicated by any other country at this point. The times have changed, the resources have changed, and now mankind has to change. On this first day of the new century -- the new millennium -- we begin by taking a new step in a new direction. Greed must be replaced by intelligence and solid deductive reasoning. Old traditional businesses & industries must be replaced by new wisdom. There is no more room for old, ignorant stubbornness. Upon this note we launch the Phoenix Turbine Builders Club. In the following months, we will step through the process of building a 100-year old design which has never been fully utilized -- the Tesla Turbine. We will cover subjects such as how and where to obtain engine cases, bearings, shafts, etc. for low cost or less. We will also cover subjects such as energy sources, fuels, combustion techniques, and applications. In the end, members will have a good working knowledge of the Tesla turbine -- what makes it work, and how to get a working model together at low cost. With this knowledge in hand, we expect our members to change the world from its childish money-centricity to a mature attitude of wise management of limited global resources. We encourage all members to share their ideas, designs & discoveries with the world through this forum. As the founding fathers of the USA resounded in Liberty Hall: "United we stand, divided we fall!" Together we can beat the enormous problems of pollution, fuel & energy shortages, and rampant shortages of necessities for the poorest of people. If we don't care, who does? Let's go!

Last updated: 05/04/06 05:03 PM

http://phoenixnavigation.com/ptbc/articles/ptbcfwd.htm (1 of 2)6/10/2006 8:40:46 PM

Forward, Phoenix Turbine Builders Club, build a low cost Tesla turbine to reduce pollution hosted by Global Motive Power Revolution


http://phoenixnavigation.com/ptbc/articles/ptbcfwd.htm (2 of 2)6/10/2006 8:40:46 PM



IntroductionBack in the 1920's Nikola Tesla designed and built several versions of his boundary layer engine. Some people call it a turbine; Tesla referred to it as a thermodynamic converter. At PNG Inc. we refer to it as a mechanical fuel cell, or turbine. Due to the politics of the day a powerful cartel of automakers & fuel suppliers pushed the rotten piston engine technology in spite of Tesla's predictions & warnings that pollution from those engines would someday choke the land. Well, here we are nearly 100 years later and his predictions have come true -- big biz has made your worst nightmares come true, all for the love of money! This is our effort to fight back against what seems like insurmountable odds, but in fact is only an illusion of what we've been told. The entire U.S. and global economy depends on the spending habits of little people -- not big people. When enough little people decide they've had enough of big business BS and really want to change their dismal futures, they will team up with organizations like ours to responsibly provide new clean technologies at the very least for themselves, their families & friends. The goal of this club is to share very simple basic turbine building concepts, tips and practices that allow persons with small shops & simple machine tools to build high-quality, inexpensive, high-efficiency Tesla turbines. It is also our goal to provide an "open source" platform for other designers, engineers & hobbyists to share what they know and discover. It is also a place for service providers to advertise basics like machine services, etc. So with that said, let's get to work & start rolling back the pollution problem starting at the grass roots level!



http://phoenixnavigation.com/ptbc/articles/ptbcintro.htm6/10/2006 8:40:55 PM

Engine Case Selection, Phoenix Turbine Builders Club, build a low cost Tesla turbine


Engine Case Selection -- page 1 of 3February 1, 2001

This month we begin with the most basic engine component -- the case. In keeping with a low-cost philosophy we'll use as many off-the-shelf items as we can. Any engine case can be used to hang Tesla turbine components on, so put some time & thought into the end application: Will I use this engine for high horsepower or low horsepower work? Will it be stationary or portable? Since old, dead snowmobiles are in abundance here in Michigan we have access to thousands of cases designed for lightweight, mediumhorsepower use. Most two-cylinder snowmobile engines put out anywhere from 30 hp to 60 hp. The bearings for these engines are produced in large numbers so the cost is low for refitting new bearings into the case -- but we'll leave the indepth study of bearings for next month. Photos A and B show a typical two-cylinder Hirth snowmobile from the outside; photos C and D show interior views. Notice that the volute air compressor housing is an integral part of the case. This limits the direction of shaft rotation clockwise only (fan end) if a main shaft mounted compressor is planned. If belt-driven or electric compressors are used, the volute housing can either be used to mount components on, or simply cut off to get it out of the way. The next thing to consider is how the bearings and shaft will work inside the case. Photo D shows a close-up of the bearing-crank assembly. Since a new shaft and bearings willhttp://phoenixnavigation.com/ptbc/articles/ptbc1.htm (1 of 3)6/10/2006 8:41:04 PM

Photo A


replace this whole assembly, we need to figure how the bearings and shaft will be set into the case to prevent shaft creep -- or axial movement. This is important, to prevent end-hung rotor components from contacting each other. Photo D shows the right-most bearing secured in place by metal snap rings on both sides. The inner bearings also have snap rings on their inner surfaces, and the left outer bearing is free to move with shaft "growing" due to heat.

Photo B

Photo C

http://phoenixnavigation.com/ptbc/articles/ptbc1.htm (2 of 3)6/10/2006 8:41:04 PM


Photo D Next Page >Last updated: 05/04/06 05:03 PM



Bearings, Phoenix Turbine Builders Club, build a low cost Tesla turbine


BearingsMarch 5, 2001

Last month we covered case selection basics; by now most of you will have located a dead snowmobile engine or something similar, and have disassembled and cleaned it. The next (and most important) step is to decide on the right bearing to drop into the case. Bearing selection is not as straightforward as you might at first think. Some of the factors involved are: size load speed type material cooling lubrication price Since we are focusing on snowmobile engines, the simplest approach is to replace the original bearings with similar types. Although it is possible to use oil-journal, air-journal and magnetic bearings, a lot more engineering is required with these types.



Most snowmobile cases are designed for a ball bearing with a bore of 30mm (millimeters), outer diameter of 62mm, and a width of about 14-16mm. Some engines are fitted with roller and ball bearing combinations, and some engines come with 72mm ball bearings at the outer positions with 62mm ball bearings at the inner. -- The Sachs case that we are using was originally fitted with 62mm ball and roller bearings. Ball bearings are used for higher speeds and their ability to handle both radial and axial loads equally.

Roller bearings will allow much greater radial loading, but at the cost of low axial loads and speed. Since the life of the engine is in the bearings, we need to examine the most important factor in maintaining long life. The first and most important factor is lubrication (and cooling). Bearings are rated for their LIO life factor -- which is basically: 90% of the bearings of a particular type will spin or turn one million revolutions at the maximum specified load before "flaking". Metal flaking from the rolling elements or races occurs as the bearing begins to break down. As flaking continues, the bearing destroys itself in a short time. So the goal is to prevent flaking at all costs. Some of the causes of flaking are: elevated temperatures high loads oscillations hammering The best strategy to deal with these destructive factors is: reduce the load on the bearing & use the best lubrication system possible. Since the lubrication system is the subject of a future session we won't go into detail here, other than to say that we'll use a jet lubrication method which will reduce heat & oscillation and allow us to use low-cost bearings at 23 times their rated speeds. Loading is really the main factor we need to address if we want to extend engine life. Since highly loading a bearing deforms the rolling element and causes it to flex as it turns, heat and metal fatigue lead to premature failure. Conversely, if there is no load at all, gaps between the rolling elements and the races allow oscillations



& microscopic hammering to pit the surfaces -- leading to larger gaps between the elements, increased hammering and again, premature failure. The ideal situation is to have a certain amount of load (or pre-load) and stay as far under the maximum load rating as possible. Working with a snowmobile case limits us to certain maximum outer diameters on the bearing. Our Sachs case limits us to 62mm bearings. To increase the load rating we can do three things: decrease the shaft diameter use a wider bearing use roller rather than ball bearings By decreasing the shaft diameter we also decrease the load carrying capability of the shaft. Since the rotors are overhung beyond the bearings, the shaft can handle only a certain amount of rotor weight at high rotational speeds before flexing and eventually failing. So there is a trade-off between shaft loading and bearing loading. A good design will limit the horsepower to around 30-40 hp (which in turn limits the overhung weight). Shaft diameter should come in at 30-35mm with minimal keyways to reduce shaft integrity. Bearings should be as wide as possible to allow greater loads, and may be a combination of roller and ball types to give us good radial and axial load characteristics. The last factor to cover is price. While a good medium-speed ball bearing is priced at $12 - $20, roller types are about double that, and high-speed angular contact ball bearings are about $160 - $180 per piece. Since we are designing this engine for low cost, our approach is to use the lower-priced ball and roller types. A good place to start your data gathering is NTN Bearing Corporation. They provide an enormous amount of information online at www.ntnamerica.com and excellent technical manuals through their distributors. Also check out Boston Bearings, FAG, SKF, Fafnir, etc. Next month we'll cover shaft basics, and how to start pulling it all together. Until next time -- keep the 21st century engine technologies moving forward!^ Top of Page




Shaft Basics & Pulling it all Together, Phoenix Turbine Builders Club, build a low-cost Tesla turbine


Shaft Basics & Pulling it all TogetherApril 2, 2001

This month we are going to take a quick look at where the design is headed and then examine a couple of ways to turn a shaft and hang parts on it. Figure 1 shows a CAD model of the Sachs case we are using for our build along with bearings, spacers, a hot rotor assembly, shaft cooler and output pulley. This gives us a pretty good idea of the case related working parts -- excluding blower, combustor, and hot rotor cover. The first and most important step before turning the shaft is to plan out placement of the parts along the shaft length, then decide how the bearings, flanges, pulleys, etc. will be attached to the shaft.

The first example (Figure 2) shows a pressed-bearing assembly. Since we are designing a relatively low horsepower turbine, the outboard or over-hung weights and radial loads will now be excessive. A 1.125-inch (end shaft) diameter will be sufficient up to about 20,000 rpm. This will allow us to use low-cost 30mm and 35mm ball bearings in the assembly.



Figure 3 shows a stepped shaft using 35mm bearings on the inner races and 30mm bearings on the outers. (Click on image to view full size.) The dimensions shown are for the Sachs case, the shaft being symmetrical on both ends. If another case is used, the cuts in the shaft must be made to correspond with bearing placements in that case. Simply use the old crank assembly to figure out bearing placements, etc. Also when turning a shaft for pressed bearings the race or area of the shaft that the bearing contacts must have an interference fit of .0001 - .0005 inches. So a 30mm bearing must be turned to 30mm + (.0001 - .0005 inches). This requires a high-precision lathe to hold that kind of tolerance. If you don't have high-precision equipment, it may be better to have a shop do the work for you. If you are going to mount the bearings yourself, it's much easier if you put the shaft in your freezer for a few hours and heat the bearing to about 300 degrees F just before assembly. Remember to use a spacer between the bearings to keep shaft axial movement in check. Next, cut tapers on the shaft just ahead of the end threads. Tapers need only several degrees to be effective, and only about one inch in length. Finally, cut threads on the two ends leaving about one inch to an inch and a half for the flange nuts. Figure 4 shows an alternative shaft design using a tensioning system for mounting and centering shaft components. Even though this design uses more components, it allows the use of lower precision tools for turning the parts. There is also more flexibility in positioning components along the shaft, so more experimentation is possible. The shaft is simply a straight piece of rod that is turned down slightly along its length to ensure roundness. Finally, the ends are stepped and threaded for the last inch to inch and a half.



Although we will cover component fitting to this type of shaft in more detail later in the series, Figure 5 shows generally how flanges, bearings, etc. are centered and held in place with locking collars. In a tensioned shaft assembly the end flange nuts compress spacers and locking collars along the entire length of the shaft, so it enhances both stiffness and overall strength. This arrangement also allows the use of 35mm bearings in all four positions so our shaft diameter is larger, able to handle larger radial loads. Next month we'll look at how to build and assemble all of the remaining shaft components...




Building & Assembling Shaft Components, Phoenix Turbine Builders Club, build a low cost Tesla turbine by Global Motive Power Revolution


How to Build & Assemble Remaining Shaft ComponentsMay 2, 2001

Last month we covered the basics of turning shafts. Keep in mind that within certain load constraints, there are several ways to fit shafts to bearings, flanges and pulleys. Even though interference fits are the simplest systems, tolerances are difficult to maintain on hobby-level equipment. The design we are using employs a system of locking collars to secure the shaft to bearings and other components. Photo A shows the shaft we turned in our shop -- complete with threaded ends and retaining pin holes. (Note: Click on the photo to view full size) In order to use low-cost ($12.50 each) high-speed (14,000 rpm) ball bearings, we turned this shaft down to 28.5 mm, allowing a 6 mm gap between the shaft and NTN 6007 (35 x 62 x 44 mm) bearing. Depending on the locking collar design, you could make the fit much tighter, but this gives us a good place to start. Bear in mind the shaft diameter and metallurgy have a lot to do with how much radial load you can place on the shaft end, so keep the shaft diameter around 1.125 inch or greater for the targeted 10-30 horsepower. If you already made your shaft to 1.25 inch (about 32 mm) you can still use the NTN 6007 or go up to a 40 mm bearing. This month we'll take a look at all of the shaft mounted components and the basics of designing and cutting them for any fit. Remember -- we are showing a design for our shaft size and bearings. Simply modify the parts for your shaft and case. Figure A shows our shaft with all of the axial mounted components. Bearings have been left out to show the locking collar sets more clearly. On the far end of the shaft we see a hot rotor flange, on the other end a drive pulley, with bearings and spacers between. The large 7/8 - 14 nuts on the two ends compress all of the parts between them. Axial loading of the bearing locking collars and flange/pulley collars centers and secures the components to the shaft. The spacers simply transfer the load and locate the parts along the length of the shaft. Without going into a lot of word-filled detail, the following pictures of our 3D CAD models should be self-explanatory.http://phoenixnavigation.com/ptbc/articles/ptbc4.htm (1 of 3)6/10/2006 8:41:42 PM


Keep in mind, we are working with a Sachs 440 case; the bearing locations for your case may be different. Also, as you compress the locking collars, some movement of bearings will take place -- you may need to use shim washers between some components, so make up or order washers to fit your shaft in various thicknesses (0.5 mm - 5 mm). The bearing locking collar consists of three pieces. The center ring is turned to slip inside the bearing inner race, a narrow slit cut on one side of the ring to facilitate expansion of the ring under pressure. If too much radial load distorts the bearing inner race, use a solid ring without the expansion slit. All three rings are cut with matching tapers (about 40 degrees) which fit together and convert a certain amount of axial load (from the end nuts) to radial load to secure the bearing to the shaft. The spacer set (Figure C) is simply a set of bushings used to maintain proper distance between shaft components, and to transfer axial loads to the shaft. The bushing center bore should be just enough to easily slip them over the shaft. Outer bushing diameters should be about 6 mm greater than the I.D. Lengths will vary depending on final bearing locations for the particular case being used. In the foreground of the shaft assembly (refer to Figure A) we see a pulley and locking collar (Figure D). Again we use a taper fit between the pulley and the collar. The collar has a slip fit over the shaft and is slit along one side to allow easier compression on the shaft. The mating taper is cut into the pulley (about 7 degrees taper). Just ahead of the pulley is a bushing spanning the distance between the pulley and the end nut & washer. Alternatively, several pulleys or one long pulley with several belt ways may be used for additional belts. Going to the back end of the shaft, you'll see our shaft cooling disk fan (Figure E). This device prevents excess heat from reaching the synthetic nitrile seals on the hot end of the turbine. This fan is simply made using 1/16-inch nickel aluminum, stainless or 4140 carbon steel plate with 1/8-inch spacers between. A snug slip fit over the shaft will be sufficient for these light weight disks. Just beyond the shaft cooling fan



is the hot rotor flange (Figure F). The flange with a slip fit outer plate clamps the hot rotor disks using (6) 5/16 or 3/8 inch bolts. Tapered collars are used on both ends of the flange to center and clamp the flange to the shaft. The taper angel cut into both the flange and collar can vary between three (3) degrees and seven (7) degrees to to gain the highest possible clamping force on this part. (Figure G) Last but not least, we cap the two ends with heavy duty washers and fine thread nuts. When the components are finally assembled, these end nuts will be cranked down to approximately 50-100 ft. lbs. to lock all of the shaft components to the shaft. Next month we'll see how all these parts fit together in the real world, and we'll start the hot rotor section.




Fitting Parts Together in the Real World, Introduction to Hot Rotor, Phoenix Turbine Builders Club, low cost Tesla turbine


Fitting Parts Together in the Real World, Introduction to the Hot RotorJune 18, 2001

Last month we discussed building the shaft-mounted components. Photo A shows our finished parts mounted with 35x62x14 mm bearings in our snowmobile case. (Click to view full size). Three parts not shown are the 60x4 mm bearing endrings, end seals, and shaft-cooling fan. We plan to order in 2.5-inch pipe for the end rings, turning down the pipe to 60 mm, then using a parting tool bit to cut the finished pipe to 4 mm widths. Seals will be ordered from Zatkoff to match a hardened and polished spacer between the end bearings and flanges/pulleys. The 4-6 inch shaft cooling fan will be made from either 1/8 inch aluminum or 1/16 inch steel and filled to the shaft between the hot rotor flange and seal spacer. For this month's work we'll concentrate on the hot rotor disk pack. The theory behind the Tesla turbine is simple. All objects are subject to "skin effect" anywhere in vacuumless space. Fluids such as air, water, oil, etc. tend to bond loosely to any surface. In aerodynamics studies we learn that this "boundary layer" extends several millimeters perpendicular to the surface, exerting less adhesive force as we increase distance from the surface. The Tesla turbine uses this surface adhesion effect to absorb and transfer the energy of high velocity gases into mechanical shaft power which can then be used to generate electricity or move a vehicle. By stacking a number of (highly polished) disks with narrow spacing between them, a high velocity gas directed in a tangential stream between the disks will transfer most of its energy to the disk pack (and finally to the shaft). The only other factor to keep in mind is that there must be an entry point for the gas (nozzle) and an exit port at the center of the disk pack. (See Figure A) There are several methods for securing the disk pack to to the shaft. Some experimenters simply fit the disks directly to the shaft using a compression nut on the shaft end and a square key fitted to a keyway milled into the disks and shaft. Our disk pack uses a modification of Tesla's advanced turbine design which secures the disks and spacers to a shaft-mounted flange. This allows us to build, assemble and balance the disk pack as anhttp://phoenixnavigation.com/ptbc/articles/ptbc5.htm (1 of 3)6/10/2006 8:42:01 PM


assembly. Using this approach gives us more freedom to experiment with various disks and spacers.

Figure B shows a fully assembled disk pack on our flange. (Click on picture to view full size.)

Figure C shows the same assembly exploded for easier viewing of the washers and star spacers. We're showing seven disks (two at 0.1875 inch and five at 0.0625 inch thick, 9.75 inch diameter) which will give us approximately 20 horsepower for running a 10 KW generator head. The disks must be highly polished stainless 316 or 4140 carbon steel, or any similar material able to handle at least 50,000 psi of tensile load. A high polish on the disk surfaces guarantees greater fluid adhesion, and results in higher efficiencies. Disks are generally 0.0625 inch thick, and the spacers are between 0.03125 inch and 0.0625 inch thick. The narrower the spacing between the disks, the greater the efficiency and torque. Although it is possible to build these parts in your shop, it will be much quicker and easier to have them lasercut from a shop so equipped. If you do the work yourself just make sure the disks fit your shaft or flange very closely. Also, when boring the (6) disk pack assembly bolt holes in the flange, disks and spacers, use an indexer or rotary table on your mill or drill press to ensure accurate placement of the holes every 30 degrees. The 0.1875 inch to 0.25 inch holes drilled around the periphery of the disk pack for securing the round washers also require accurate indexing. Finally, when bolting the disk pack together use six high-strength 0.25 inch to 0.3125 inch bolts for the flange, and either bolts or threaded inserts/rivets for the spacers/washers. Well that about wraps it up for this month; getting these somewhat complex spacers and disks milled yourself orhttp://phoenixnavigation.com/ptbc/articles/ptbc5.htm (2 of 3)6/10/2006 8:42:01 PM


made up by a fabricator should keep you busy for a while. Until next time, keep those metal chips flying!




Hot Rotor Case, Lubrication & Energetic Fluids, Phoenix Turbine Builders Club, low cost Tesla turbine


Hot Rotor Case, Lubrication & Energetic FluidsJuly 9, 2001

This is the seventh and final regular article on how to build a Tesla turbine from discarded engine cases. After covering this month's topics of the hot-rotor case, lubrication and energetic fluids, you will have a working knowledge of applying boundary-layer turbine principles to any kind of motive power application.

Hot Rotor Case

In Figure A we see the completely assembled turbine just prior to fitting the hot rotor case components.

Figure B shows the hot rotor case back plate attached to an upper and lower plate, which are in turn bolted to the bearing case. The upper plate is locked down using the pre-existing cylinder tie-down bolts, while the bottom plate is secured using the engine mounting bolts.



Spacing between the hot rotor case and the adjacent rotor pack is not critical for efficient engine operation. A clearance of approximately 0.125 inch is about right -- just make sure your shaft assembly has little or no end-play or else the disk pack will contact the housing! Figure C shows the outer case ring and nozzle installed. The clearance between the outer periphery of the disks and the case ring should be about 0.125 inch. The nozzle is simply a square or round channel welded to the case ring and positioned tangentially to the outer edge of the disk pack. Depending on the gas/fluid used, nozzle inserts of various diameters are secured inside the channel to obtain the highest fluid velocity. Efficiency increases as the square of the fluid velocity, so the faster you move the fluid, the more efficient the engine. Generally speaking, a convergent-divergent nozzle insert will yield the highest fluid velocities. Also, an important design tip to keep in mind: the width of the nozzle should never be wider than the disk pack -- this will ensure that gases will not escape past the end disks. Figure D shows the end plate bolted to the hot rotor case assembly. Again, the clearance to the disk pack is sufficient at about 0.125 inch.

LubricationSince the life of the turbine is in its bearings, special care must be taken in providing adequate lubrication for the speeds involved. The best ways of becoming familiar with bearing lubrication methods are to either download the information directly from NTN or Timken, etc. online, or order their bearing manuals. NTN's excellent manual -- catalog #2200II/E -- provides all of the know-how for lubricating their bearings for long life in the speed ranges we address. For very short test runs you can simply fill the case to the middle of the lower rolling elements -- using a high quality turbine/lathe oil. Mobil provides an excellent DTE 24 series oil which will work in place of turbine oil, and is relatively low cost -- about $10 to $12 per gallon. For extended engine use, use a lubrication method as described in the NTN manual -- splash, drip, circulation, spray, and jet, with jet methods allowing up to three times the rated bearing speed.

Energetic FluidsTo power your turbine you may use a number of fluids including compressed air, steam, hot gas, or a combination of all three. In fact, for certain applications such as torque converters and transmissions you can use heavier fluids such as water and oil.



The application of Tesla's turbine to any power situation is only limited by the imagination!

ConclusionWell, that about wraps it up for this series of articles. As some of you get your engines built and running I'm sure you'll have minor problems that need resolving. Drop us an email for help and we'll see what we can do. Coming up in future articles... feedback from a turbine enthusiast who built his own pulse combustion Tesla engine! Let us know how your project turns out!




Tesla Turbine Pulse Combustion Project, Phoenix Turbine Builders Club, low cost Tesla turbines


Pulse Combustion Project by a Tesla Turbine Enthusiast!August 27, 2001

This month we are taking a look at pulse combustion as a means of powering the hot rotor. The following project was submitted by Luis Mendonca with permission to publish his work for the benefit of all turbine builders. We have included Luis' comments, photos and drawings; for more information contact him through his email.

Thu Jun 21 18:57:55 2001

Tesla ProjectFor several years I have been developing rocket and gas turbine engines. At one time I had the idea of building a pulse combustion turbine, so I developed several pulse combustion chambers working with conventional reaction turbines. Then I heard about a simple and reliable turbine, the Tesla turbine, and I built several models. The one in the pictures was projected to work on hot pulse combustion gases with a heat transfer to produce steam, to be injected also in the turbine. The disks are 400 mm in diameter and 26 in total. I have achieved 5400 rpm and 150 c temperature at the exhaust port (it's not shown in the picture because the engine was opened for the photo). I couldn't measure the Hp because I have no measurement equipment. Now I'm working on a new type of turbine design by me; it has only one disk and a pulse combustion boiler, works on steam and hot combustion gases all mixed at conventional time. I have already worked with 20000 rpm , no or few vibrations. The disk or turbine has no blades and works on a similar theory that Teslas do. I use propane or natural gas as fuel; at the exhaust I have condensated water an almost 0 pollution gases


Tesla Turbine Pulse Combustion Project, Phoenix Turbine Builders Club, low cost Tesla turbines

regards Luis Mendona [email protected]

Mon Jul 2 17:10:28 2001

First Combustion ChambersHi, these drawings were my first experiences with pulse combustion chambers. I have made them all. (I will try to scan the real pictures.) These experiences gave me the idea of a simple pulse combustion chamber, similar to a pulse jet engine. The differences about normal pulse jet is that the valve is much more reliable, and has a servo or an electronic fuel injector. For the moment I am developing my new turbine with the pulse combustion boiler. When I finish it, I'll send some pictures on the test stand. Hope that you understand the drawings, Regards Luis Mendona [email protected]




From California, a Member's Tesla Turbine Generator Project, Phoenix Turbine Builders Club, low cost Tesla turbines


From California: A Member's Tesla Turbine Generator ProjectSeptember 10, 2001

Don Thrasher, a bona fide experimenter from California, contacted us last April with plans to build a turbine generator. He is using a 36-inch rod from a hydraulic cylinder (2.5 inch diameter) for the shaft and eventually selected a VW engine block for his project. After recommending the type of materials to use for both the shaft & the disks, we sent along some DXF files so he could laser cut the disks. (See photos below) Don gave us permission to publish details of his project and we have included some of his comments and photos. For more information contact him through his email: Don Thrasher [email protected]

Fri Aug 31 16:07:55 2001

Here are some pictures of my disks and washers. I plan on using the arc washer unless the regular star washer works better. Once I find a good setup I'll cut everything out of stainless and polish to increase the efficiency. -- DonWed Sep 5 20:27:07 2001

Since your last update I have been in contact with Pat Nealon thanks to your "members page." He is going to help me with the design of the combustion chamber as soon as I am able to provide him with a little more info. For now I plan to build a 40-50 horse turbo shaft. I have cut two disks out of 7 ga., eleven disks out of 16ga. and enough arced star washers out of 20 ga. to space all of the disks. I have only cut one of the regular star washers that you see in the pictures. ... I plan to use your cooling disk fans to duct out the heat from around the hot rotor assemblies and pump in fresh air. I will also use that high temp exhaust wrap on the input and output tubes -- they use it onhttp://phoenixnavigation.com/ptbc/articles/ptbc8.htm (1 of 3)6/10/2006 8:48:01 PM


headers to reduce the engine compartment temperature and it also increases the horse power by keeping the exhaust gasses hotter and moving faster. I will gladly accept any advice or ideas that people may have to offer on my design so far. Thanks for all of the help so far! -- DonSat Sep 8 16:41:52 2001

Here are some pic's of the compressor blade off of a turbocharger I plan to use to feed the turbo shaft... I will be using a T04 turbocharger from Garrett to run a combustion chamber and the exhaust from that will feed my turbo shaft. Don






Update on Tesla Turbine Pulse Combustion Project, Phoenix Turbine Builders Club, low cost Tesla turbines


More from Luis Mendonca: Pulse CombustionSeptember 11, 2001

We just received the following project update by Luis Mendonca including more drawings. For more information contact him through his email.

Mon Sep 10 17:42:25 2001

Hi. Here are some of my ideas of pulse combustion chambers (the complicated ones, now they are much more simple). I will be glad to know that some one will use this ideas. If any questions...just ask. Luis Mendona [email protected]

Mon Sep 10 18:18:23 2001

More to come... I will scan my pictures of more 2 Tesla turbines running on water vapor at 10 bar and 150 degrees c, on the power stand at the Coimbra Engineer University


Update on Tesla Turbine Pulse Combustion Project, Phoenix Turbine Builders Club, low cost Tesla turbines




Update on PTBC Tesla Turbine Project, Phoenix Turbine Builders Club, low cost Tesla turbine


Update on PTBC Tesla Turbine ProjectOctober 22, 2001

October is a very mystical time of the year. Projects that creep along during other months suddenly seem to pull together in October almost by a power of their own. That's the way it has been for our in-house turbine project. We have a pretty good line up of designs, experiments and updates from a couple of club members so hang on... here we go.

First of all I want to share a couple of photos of our efforts here in Michigan. The first photo shows our Sachs case with all the shaft components assembled and torqued down. The hot rotor flange is on the right, the output pulley on the left. Just below the bearing case are the disks, star washers and hot rotor case end plates -- as we received them from our laser cutter. The time and effort saved by having a local shop laser cut these parts was well worth the relatively low cost. For our first stage prototyping we are working with a low-cost 836 steel; for final prototypes we'll specify either 316 or 416 stainless for all of these parts. The next photo shows most of the parts assembled and ready for the hot rotor case ring and end plate.

Test ResultsAfter final assembly of the hot rotor section we modified the outlet of our pulse combustor and attached it to the turbine nozzle. Although the combustor cycled properly, the rotor did not self start. The nozzle being a 1" x 1" square tube did not generate enough directed energetic gas between the plates. Most of the gas energy went around the disks and exited the hot rotor case without transferring power to the disk pack. After grinding a nozzle insert and fitting it into the nozzle tube, the resultant slot impeded the pulse combustion cycle (using low pressure air).

ConclusionsTesla turbines do not operate under conventional turbine principles. Bladed turbines require large volumes of relatively low velocity fluid, whereas Tesla turbines require lower volumes of accurately-directed high velocity fluid. Tesla turbines work extremely well with steam, air, or hot gas fed to a slotted nozzle at around 80-160 psi. They do not work well with typical simple pulse combustor techniques.



In order to get pulse combustion to work properly with a Tesla turbine, air and fuel must be delivered to the chamber at pressures suitable to deliver approximately 80-160 psi of hot gas to the working rotor nozzle.

Future DevelopmentsIn the coming months we plan to experiment with steam and improved combustion systems for powering up the hot rotor section.

Other Club Member Development UpdatesDon Thrasher sent us this photo of his star washer improvements. (For more information on his generator project, see our September 10 article.)

Also, Luis Mendonca sent a number of photos showing some of his work with Tesla turbines. The photos show some of his early work with steam or compressed air driving a turbine; other photos show his more recent work with pulse combustion techniques.






Combustor Improvements, Nozzle Construction, More Test Results on the PTBC Tesla Turbine, Phoenix Turbine Builders Club, low cost Tesla turbines


Combustor Improvements, Nozzle Construction & More Test ResultsNovember 27, 2001

Here we are towards the end of November -- almost a full year of action-packed Turbine Builders Club activities. Last week we were busy entertaining family visitors, Yooper style, before sending the Trolls merrily on their way. For those of you who are unfamiliar with Michigan's Upper Peninsula, Yooper is a name for Upper Peninsula residents. A Troll is a down-stater who lives "under the bridge" (Mackinaw Bridge connecting two peninsulas), and Yooper-style entertainment involves beer, snowmobiles and shooting guns. By now most of you should have some semblance of a turbine put together, ready for trials. This month we will cover combustor improvements, construction updates, and more test results.

Combustor ImprovementsLet's start with combustor improvements. Photo (a) shows our basic combustor with a new threaded exhaust tube and a couple of reducers. This allows us to step the exhaust down from a 2-inch tube to a 1.25-inch tube. The gas vaporizer was rerouted through the side of the 2-inch tube, making it a lot easier to connect the combustor to the turbine. Also shown in the photo to the right are the spark plug and vaporized fuel delivery tubes. Photo (b) shows a close-up of our fuel and spark controller/sequencer. (Click on image to view full size.) The potentiometer on the far right controls the frequency of the combustion cycle from about 1 cycle per second to about 100 cycles per second. The sequencer sends a control power pulse to an electronic gas valve immediately followed by a burst mode ignition pulse packet to the spark coil. We've tested the combustor in continuous and pulse modes. Continuous combustion delivers a massive amount of heat with very low velocity and kinetic energy. While this may be beneficial for steam generation, it is not ideal for kinetic energy machines like the Tesla turbine.



Pulse combustion, on the other hand, delivers less heat volume, requires less fuel, and produces a very energetic, high velocity shock wave. While these shock waves will destroy piston and conventional turbine engines, the more robust Tesla design easily withstands and seems to work very well with this type of combustion. Photos (c) and (d) show our turbine assembled and fed with a compressed air line.

Photo (e) shows me with one of my helpers running a spin test on about 150 psi of compressed air.

Nozzle ConstructionYou may have noticed from Photo (c) that we are using 1-inch square tubing for our inlet nozzle. This allows us to use nozzle inserts with a horizontal slot profile, distributing high velocity gas equally across the width of the rotor or disk pack. Presently all of our initial tests use compressed air as the fluid. Refinements to our combustor technology will allow us to eventually move to hot gas. To shape a nozzle insert, we started with a 3-inch piece of 0.75" x 0.75" square steel stock. Using a small electric hand grinder, the square stock was carefully ground to approximate the cross section of an airplane wing. (See Figure 1). A (0.25-20) thread was tapped through the insert to attach and hold it in the 1-inch nozzle.



In our first test the insert was oriented to configure the nozzle as a convergent type. (See Figure 2)

In the second test the insert was flipped 180 degrees to configure the nozzle as a convergent-divergent supersonic nozzle. (See Figure 3)

Nozzle Test ResultsThe air compressor we are using is relatively small. It takes about 10-12 minutes to pump up the 30-gallon tank to 150 psi. Even though the nozzle slot is only 0.125-inch by 1-inch wide, the air tank is exhausted in less than 30 seconds. Since the momentum and energy are both related to fluid mass times velocity, we had to use a 0.5inch feed line to the turbine nozzle to get enough air mass delivery. Using the nozzle insert in its convergent or subsonic mode, the turbine spooled up with no problem using an initial 150 psi tank pressure. It continued to spin until the air pressure dropped to 20 psi. Again, reconfiguring the nozzle with the insert oriented for convergent-divergent supersonic mode, the turbine spooled up easily on 150 psi. This time it continued to spin even when the air pressure dropped below 20 psi -indicating a higher energy transference efficiency when using supersonic nozzles. The conclusion is that the gas or energetic fluid must reach supersonic speed before entering the disk pack for highest overall efficiencies -- the turbine chamber and disk pack cannot be used as the divergent section of a supersonic nozzle.

Next month we'll review the year's accomplishments, make a few projections for progress in 2002, and make a few suggestions for design improvements -- maybe even have more test results.



We'd also like to hear from others of you who have working turbines up and running, and what results you are getting. We'll only make progress by sharing what we know and discover.Last updated: 05/04/06 05:04 PM



Combustor Test Results, More on Nozzles & Combustion Sequencer Schematics, Phoenix Turbine Builders Club, low cost Tesla turbines


Combustor Test Results, More on Nozzles & Combustor Sequencer SchematicsDecember 24, 2001

Here we are in the twelfth month of our turbine builders club. A lot has been accomplished in 2001 -- if you have followed the designs in this column you should have a basic Tesla turbine assembled and operating on compressed air or steam. If not, all of the drawings and tips are on this site to get you up and running.

Combustor Test ResultsWe made a couple of minor modifications to our basic vortex combustor; a slotted tube was inserted between the combustion chamber and exhaust tube to help contain combustibles in the main chamber. Once the combustor was up to operating temperature the modification seemed to slightly improve firing reliability, but cold startup was still a problem even using propane. After choking the inlet to the main air induction blower and setting the fuel valve to full open continuous burn, the unit fired up with no problem. After just a few minutes of burn air inlet was opened to allow lean-burn mixing -- no problems. So the lesson here is that during cold start conditions the fuel-air mix must be on the rich side until the chamber heats up -- then it will function reliably in lean-burn mode.

Convergent-Divergent NozzlesRecently we received an email questioning our explanation of convergentdivergent nozzle practice. Since both inlet and outlet nozzles are extremely important in achieving efficiency with a Tesla turbine, we were already planning to post a scanned page for study. Well, here it is, by the book -the convergent-divergent nozzle (Figure A).Figure A Nozzles

Combustor SequencerDon Thrasher requested a copy of our combustion sequencer schematic. Referring to the block diagram (Figure B), the basic operation is as follows:



Figure B Block Diagram

The variable rate main clock controls the combustion sequence and the frequency of the cycle. A rate control potentiometer varies the cycle from about one cycle per second to approximately 100 cycles per second. A cycle begins with the main clock sending a signal to the fuel gate valve driver transistor to open the (normally closed) fuel valve to admit propane gas into the combustion chamber, where the gas and blower-driven air are mixed. As soon as the fuel valve pulse goes low another pulse is sent to the signal logic gate, switching the 1000 hz clock to the spark coil driver. This in turn sends a high frequency spark burst to the plug, making ignition more reliable. Figures C, D, E & F show wiring diagrams for the power supply, sequencer, and coil drivers.

Figure C Combustor Sequencer Power Supply Figure D Combustion Sequencer



Figure E Spark Coil Driver

Figure F Fuel Valve Driver

Member InputLuis Mendonca sent us pictures of his completed pulse combustion turbine. This is a new design of his, and from the following pictures we can see that it is operational.

Click on picture to view this photo series

Samuel Falvo also sent us pictures of his air-driven Tesla turbine demonstrator made from cardboard and a soda straw. He says that everyone who sees it run (on lung power) is amazed at the amount of torque it produces for its size and energy input.

Click on picture to view this photo series

Winding Things UpThis year we've accomplished quite a bit -- we have: posted working drawings detailing how to build a high quality Tesla turbine from scrapped engine blockshttp://phoenixnavigation.com/ptbc/articles/ptbc12.htm (3 of 4)6/10/2006 8:49:41 PM


built and tested the turbine with excellent results explored the basics of combustion What can we expect in the coming year (2002)? First of all we need to remind ourselves that the purpose for exploring new engine types is to someday move the world away from inefficient, polluting piston engines into motive power solutions that will ease the coming energy crunch, and allow us to once again breathe fresh air. Besides, problem solving and creating new working machinery is just plain fun. Since combustion efficiency is one of the biggest challenges facing mankind, 2002 will be the year for introducing new technologies to solve the fuel shortage and emissions problems plaguing the world today. It is our goal to be in the forefront of developing and delivering these solutions in the coming year. Stay tuned for more discoveries in the months ahead. Ken Rieli, CEO PNGinc^ Top of Page




Completed Pulse Combustion Turbine by member Luis Mendonca, Phoenix Turbine Builders Club, low cost Tesla turbines


Completed Pulse Combustion TurbineDecember 24, 2001

We just received the following photos from Luis Mendonca. For more information contact him through his email: [email protected]

Sun Dec 9 16:37:38 2001

Click on photo to view full size



http://phoenixnavigation.com/ptbc/articles/ptbc12a.htm6/10/2006 8:49:53 PM

Air Driven Paper Turbine by Samuel Falvo, Phoenix Turbine Builders Club, low cost Tesla turbines


Air-driven Paper Model Tesla TurbineDecember 24, 2001

Samuel Falvo II sent us these pictures of his PT-3 with comments following:

http://phoenixnavigation.com/ptbc/articles/ptbc12b.htm (1 of 2)6/10/2006 8:50:03 PM

Air Driven Paper Turbine by Samuel Falvo, Phoenix Turbine Builders Club, low cost Tesla turbines

Click on photo to view full size

Sun Dec 2 04:02:53 2001

"I was perusing your website and found that you had what appeared to be a nice combustor and an excellent turbine setup ready to be mated. Excellent news! I thought I'd jump in there and let you know that, with my exorbitantly extensive resources available to me, I have created and finished the third paper model turbine: the PT-3. It's a 4" diameter turbine with roughly 1/3rd of its active area ported for exhaust. The rotor assembly is constructed of a stack of 8 4" discs spaced roughly 1/32" apart using paper spacers (which double as "rivets" in traditional metal designs). The shaft is a plastic soda straw. The rotor housing is an octagon (the best I can do with corrugated cardboard to approximate a circle) in shape, and has ports for exhaust and intake. The bearings are raw -- the plastic soda straw just threads through some holes in the cardboard. However, these holes have been primed with graphite from a #2 pencil for lubrication. Results? I've *floored* everybody I've shown it to. Using breath power alone, I've gotten it to spin up to around 3000 RPM or so (based on the note it produces relative to my car's engine's note). My mechanically inclined friends try to put a load on the turbine by grabbing the straw. If they grab hard enough, of course, it does manage to stall. However, they're reaction every time is, "Holy $#!+! This thing has a *lot* of torque!" Keep in mind that this turbine has to overcome all the friction of paper-on-paper too! Just imagine what it'd be like if it sat on reasonable ball-bearings. My co-workers at the office always are playing with it. I know of several people here at the office who have their own straws just so they can blow into my rotor housing and make it spin."



http://phoenixnavigation.com/ptbc/articles/ptbc12b.htm (2 of 2)6/10/2006 8:50:03 PM

New Directions in Turbine Design, Phoenix Turbine Builders Club, low cost Tesla turbines


New Directions in Turbine DesignJanuary 23, 2002

Here we are at the beginning of the year 2002 in the snowmobiling capital of the country, experiencing record snowfalls -- in the wrong direction. Instead of having several feet of accumulated snow on the ground, we have several inches. People who deny that we are well into global warming trends are like the classic ostrich -- with their heads stuck in the sand (or somewhere else!) The real purpose for experimenting with turbines is to arrive at a new engine design that will replace piston engines -- which account for up to half of the world's pollution problems. Those who believe the BS coming out of the White House about how a new welfare program for the auto industries will result in affordable fuel cell vehicles by 2008 ought to have their heads examined. After hundreds of millions of dollars thrown at them for the PNGV, we still don't have 80 MPG cars in our driveways. In spite of the rhetoric coming from politicians and industry "leaders", it's still up to us "little" guys to produce real technology.

Beyond the BoxThis month we are going to look beyond the "Tesla Turbine Box" and examine a new direction for experimentation. We know that the boundary layer effect works in a typical Tesla type turbine with closely spaced disks. What we need to know is how well it performs compared to bladed-disk hybrid designs. In order to study such a comparison we need to build a couple of disk packs with identical spacing and modify only the elements between the disks. Referring to Figure A we see a typical Tesla configuration using his improved design with a star washer and round washer set. (Click on picture to view full size.)


New Directions in Turbine Design, Phoenix Turbine Builders Club, low cost Tesla turbines

Figure B shows our new direction in simple bladed systems. There are many factors you have to keep in mind when working with blades or, in this case, wing cross-sections. Disk spacing will have a big effect on winglet lift and drag properties. Some of the variables include: wing profile angle of attack relative to the inflowing gas the changing angle of incidence as the rotor and gas change their working relationship Since we just completed working drawings and sent them to our laser cutter today, we won't have test results to post until next month. What we really need is input from club members who have experience in turbine design & development, particularly in the field of high-pressure combustors with high efficiencies. If we are going to solve these manmade ills of industry we need to get more scientists, engineers and experimenters to work on projects other than money-making and stocks-gambling. Until next time... Ken Rieli^ Top of Page Last updated: 05/04/06 05:04 PM



Fuels Solutions, Phoenix Turbine Builders Club, low cost Tesla turbines


Fuels SolutionsFebruary 26, 2002

As we mentioned last month, our main focus this year is combustion and how to effectively apply new combustion techniques to low-cost, easy-to-construct turbines such as the Tesla design. This in no way constrains us to a strict Tesla system, but merely serves as a starting point for more efficient design strategies. In order to obtain the best efficiencies from fuel to shaft horsepower we have to look at the entire process -from fuel in its unburned, raw state, through the transforming of gas kinetic energy into mechanical power, and finally, the exit of hot gas from the machine and the recovery or loss of energy in the entire system. First of all we have to decide on the combustion mechanism -- do we want a continuous burn or pulse burn? In previous discussions we finalized on pulse burn as a more efficient mechanism for reaching high velocity gas states with the lowest heat loss. A pulse burn mechanism is similar to the constant volume combustion model of the piston engine, rather than the constant pressure system of conventional turbines. While conventional turbines are higher than piston engines in horsepower per pound of engine, they are less efficient (in most applications) in terms of fuel efficiencies. To obtain good pulse combustion we need an energetic fuel that will burn easily even at low temperatures. Since our operations are located in northern Michigan, we usually have a few months of cold temperatures -useful for conducting certain cold condition tests. In Photo A you can see a simple test bed for determining which fuels are best suited to our work. The equipment used was all off-the-shelf and easy for anyone to assemble. The main system consists of an air compressor driving a paint sprayer which atomized the test fluid, spraying it past a spark plug driven by a high voltage furnace coil. Photo B shows another apparatus we dismantled from a fuel oil furnace. The main difference between the two devices is that the fuel oil gun uses a high pressure pump to drive liquid through a small nozzle for atomization. The paint sprayer uses medium- to low-pressure air to draw liquid from the tank by venturi vacuum, then forces it through an atomizing nozzle. The advantage of the paint sprayer system is that some fuel/air premixing is done in the sprayer. The advantages of the fuel oil gun are compactness and lower power requirements. As we eventually move towards a final design, we'll use elements of both systems for best overall results.



FuelsSome of the fuels we experimented with were: alcohols kerosene naphtha acetone toluene (xylene) fuel oil white gas (Coleman fuel) gasoline (motor fuel) soy oil mineral spirits Besides testing these liquids as single component fuels, we also blended various combinations to establish a baseline of characteristics. For instance, the alcohols would not mix with the oil group -- including naphtha, gasoline and mineral spirits. We even tried the gasoline additives designed to remove water from your automobile fuel tank. Although the alcohol and water mix, they in turn do not mix with gasoline -- which is why your car doesn't always perform right. Using the paint sprayer system, we tested all of the single and multi-component fuels for ignition, burn and smoke characteristics. Some preliminary results demonstrated that: Alcohol, acetone and toluene (xylene) would not ignite under cold conditions using our spark arrangement. Kerosene, fuel oil, naphtha, gasoline, white gas, and mineral spirits all ignited easily but burned with more or less energy. Soy oil burned easily in combination with kerosene, naphtha, mineral spirits, but also produced the most smoke. Of all the components we tested, the overall winner was mineral spirits. Even though mineral spirits is a multicomponent fuel with boiling points from 142 degrees C to 187 degrees C, it is more energetic than gasoline (motor fuel) -- which is a blend of hydrocarbons with boiling points from around 90 degrees F to about 435 degrees F. This witch's brew of white gasoline and industrial waste is not only expensive to produce, unstable in storage, mixed with 20% to 25% water during summer sales -- it is also part of the political haggling process in Washington to complicate the country with over 40 unique blends of fuel. What we have discovered is that all of the price haggling and political intervention and control over motor fuel is really unnecessary. By shifting the country to a simple distillate fuel like mineral spirits, we can eliminate all the various blends of fuels -- which will result in lower prices starting at the cracking plants. To utilize more of the fuels base, simple blends of mineral spirits with kerosene and even soy (and other plant oils) will move the country very quickly towards energy independence. Now comes the tricky part. Gasoline piston engines, as they are designed today, do not work well with mineral spirits, fuel oil, or even pure alcohol. Petroleum distillates detonate too easily in today's engines, resulting in rapid destruction of the engine. Slowing down the burn to avoid detonation results in poor fuel economy (as much as 40% of the fuel in your tank is simply blown out the exhaust port), which is why catalytic converters are mandated -- to burn the wastedhttp://phoenixnavigation.com/ptbc/articles/ptbc14.htm (2 of 3)6/10/2006 8:50:32 PM


fuel. This brings us to the next point. To utilize all of the energy in fuel we have to pre-process the fuel into a near 100% burnable state. Liquids do not burn -- only vapor or gas phase fuels burn! While carburetors and fuel injectors work to convert liquid fuels to vapor state, the fuel still acts as a quasi-liquid even in a hot cylinder. The only way we can achieve near-perfect combustion is to start with a gas phase or gas state fuel. Photo C shows one of our primary stage components for liquid-to-gas state devices. It's operation is really quite simple; a closefitting pipe is welded (gas-tight) around a smaller diameter threaded pipe. An inlet and outlet are welded to the outer pipe. As heat from an engine or combustor passes through the center (threaded) pipe, fuel is forced through the outer cavity, transforming it to a vapor/gas phase (dependent on the heat). Photo D gives us a brief glimpse at a parallel development project in an early construction stage. This fuel processor is designed to convert any liquid-state hydrocarbon into a gas-phase fuel for use in any type of engine -- gasoline piston, diesel piston, all types of rotary & turbine engines, etc. Well, that's it for this month. Next month we will feature a special test between a strict Tesla disk design versus a proprietary hybrid design of our own, using thin section winglets mounted between the disks. We'll also cover some of the inlet nozzle issues. Anyone interested in learning more about our fuel processor will want to link over to our PNGinc site. 'Til next time -- keep the motive power revolution rolling! Ken Rieli^ Top of Page Last updated: 05/04/06 05:04 PM



More on Inlet Nozzles, Special Test, Tesla Disk Design Vs. Phoenix Hybrid Winglet Design, Phoenix Turbine Builders Club, Tesla turbines


More on Inlet Nozzles & Special Test: Tesla Disk Design Vs. Phoenix Hybrid Winglet DesignMarch 27, 2002

Last month we examined how various hydrocarbons perform under cold conditions. By vaporizing liquid fuels and passing them over an ignition spark we were able to determined which would be suitable for all weather conditions. We also took a brief glimpse at a couple of our fuel processor components. We're going to start out this month's study by clarifying what makes the Tesla turbine operate and how components work together to produce an efficient design. We'll also take a look at how geometry changes to the disk pack affect efficiency.

As stated by Nikola Tesla, his disk turbine is best used as the primary stage of a multi-stage system, followed by a Parson's type bladed stage. The Tesla design is more efficient in converting high pressure, lower volume kinetic gases into rotary power, whereas bladed turbines are more efficient at converting lower pressure, high volume gas into power. A good starting point is around 125 psi - 150 psi of pressurized gas, air, etc. to feed to a disk type turbine. Between the supply of pressurized gas and the disk pack we need to insert a nozzle to convert static pressurized gas to a high velocity/high kinetic energy fluid. The best and most efficient way of doing this is to use a convergent/divergent nozzle. Figure 1 shows a model of convergent/divergent nozzle similar to a design published by NASA Tech Briefs (January 2001, pg. 60). Pressurized fluid enters the nozzle from the left at subsonic speed. As the fluid passes the largest diameter of the insert, it accelerates to the speed of sound. Continuing its flow to the right, the fluid expands rapidly, exchanging heat energy for supersonic velocity. The NASA design is easier to build than a DeLaval nozzle since the insert is machined rather than the casing. An added benefit is that the outflowing fluid converges upon itself to the center of the nozzle rather than following the outer casing. For more information visit www.nasatech.com, Mechanics section, paper #KSC-11883. After we achieve a supersonic flow of gas through the nozzle, the next challenge is to convert the highly energetic gas into work. Early bucket type turbines operated almost completely by impulse -- by the working fluid impacting the bucket. Today's axial flow turbines use blades mounted perpendicularly to a central hub, and rotate perpendicularly tohttp://phoenixnavigation.com/ptbc/articles/ptbc15.htm (1 of 4)6/10/2006 8:50:41 PM


the flow of gas through reaction -- or changing the direction of fluid flow. (Figure 2)

While the Germans were developing pure axial flow turbines just prior to WWII, Whitney and the British were developing a centrifugal-axial flow turbine. (similar in design to Figure 3)

The third type of conventional turbine uses centrifugal wheels both for compressing air and for the hot or working stage. (Figure 4) Work is extracted in this type of turbine using a combination of impulse and reaction forces on the hot rotor. (mixed flow)

Tesla Turbine DesignTesla turbines fall into the centrifugal category, but differ in the energy exchange mechanism. Conventional centrifugal turbines use blades to convert kinetic energy to shaft horsepower. Tesla's design uses the viscous effect of closely spaced disks, along with a number of small round washers to extract and convert the energy. (Figure 5) Tesla stated that the round washers placed around the outer perimeter were absolutely necessary for start-up torque, and to give an advantage under highly loaded conditions. Understanding how the geometry of this outer periphery region interacts with the nozzle and the fluid passing through the nozzle is the key to disk turbine efficiency.

When Tesla was developing his turbine, a working knowledge of aerodynamics was held by very few people around the world. Even Tesla know very little about the subject, but he knew from extensive experiments what did and did not work. (Figures 6 & 7 show Tesla's inlet nozzles) Today we have a much better understanding of the key role aerodynamics plays in turbine design and operation, and this is the area where we can make relatively small changes to the basic design and obtain great improvements inhttp://phoenixnavigation.com/ptbc/articles/ptbc15.htm (2 of 4)6/10/2006 8:50:41 PM


performance.

Phoenix Winglet DesignBy replacing the round washers in Tesla's original design with thin-section winglets we are able to convert the kinetic energy of the gas using wing lift force (reaction) rather than the drag force of a round washer. As the fluid leaves the trailing edge of a winglet it continues to give up its energy through viscous effect -- if the winglet angle of attack is sufficiently small.

From the LabsIn our experiments we built up two disk packs which were identical in every way except for the geometric shapes placed between the disks. The "control" disk pack was built to Tesla's specs (using a spacing of 0.125 inch between the disks) and was used to compare experimental variations in the second disk pack. We used a small air compressor to charge a 20-30 gallon tank to 100 psi for each test cycle. A frequency counter was used in conjunction with our custom built Hall-effect shaft rotation detector to compare runs. As long as every run begins with the same air pressure (100 psi), the disk pack configuration yielding the highest rpm is the most efficient. While I won't go into much detail this month concerning test results, here is a brief summary:

a) Tesla configuration average peak rpm: b) Phoenix winglets at 37 degrees angle of attack average peak rpm: 2040

1520



ConclusionsUsing a winglet in place of the outer periphery round washers of Tesla's design, we were able to gain approximately 30% higher efficiency. Based on other experimenter's test results with direct combustion and the Tesla configuration, we should expect our overall fuel to shaft efficiency to come in around 31% -- placing our design right between gas piston and diesel piston efficiencies.

Beyond TeslaNext time we'll have photos of our test bed setup, and will discuss in more depth the aerodynamic differences between Tesla's original design and the Phoenix improvements. Till then, keep moving forward. We've got the sticks-in-the-mud on the run! Ken Rieli^ Top of Page Last updated: 05/04/06 05:04 PM



Turbine Construction Details, Beyond Tesla, Our Comparative Tests, Samuel Falvo Report, Phoenix Turbine Builders Club, Tesla turbines


Turbine Construction Details, Beyond Tesla, & Our Comparative TestsApril 29, 2002

I. Turbine Construction DetailsIn response to members' requests, we're going to start out this month by showing detail photos on how we attached the turbine case backplate to the bearing housing, and how the disk pack flange cleared the backplate. We have also included photos of the nozzle inserts and how they fit the case ring.

Ken RieliSection II -- Next Page >

^ Top of Page


Phoenix Turbine Builders ClubFREE Open Source Forum http://phoenixnavigation.com/ptbc/home.htmhttp://phoenixnavigation.com/ptbc/articles/ptbc16.htm (1 of 2)6/10/2006 8:50:56 PM

Turbine Construction Details, Beyond Tesla, Our Comparative Tests, Samuel Falvo Report, Phoenix Turbine Builders Club, Tesla turbines


Hamish Edgar on Tesla Disk Spacing, efficiencies, Phoenix Turbine Builders Club, Tesla turbines


Hamish Edgar on Tesla Disk SpacingApril 29, 2002

Thanks to Hamish Edgar in New Zealand for sharing the following solutions. 02/12/03 update: Hamish can be reached at [email protected]

Hi All, First I'd like to say that I completely agree with your philosophy... Commercially driven research is just going to give us more of the same. I've been lucky enough to get my hands on two of the papers about Tesla

tesla turbine technicals

Documents

turbine basics

tesla turbine enthusiast

turbine sizing

inch turbine

teslas turbine

turbine efficiency

ken rieli solar steam

order tesla turbine