starting and auxiliary power systems
TRANSCRIPT
![Page 1: Starting and Auxiliary Power Systems](https://reader033.vdocuments.mx/reader033/viewer/2022061204/547eee8db37959582b8b560d/html5/thumbnails/1.jpg)
STARTING AND AUXILIARY POWER SYSTEMS
![Page 2: Starting and Auxiliary Power Systems](https://reader033.vdocuments.mx/reader033/viewer/2022061204/547eee8db37959582b8b560d/html5/thumbnails/2.jpg)
The purpose of any starter system is to accelerate the engine to the point where the turbine is producing enough power to continue the engine’s acceleration. This point is called the self-accelerating speed. The proliferation of gas turbine starter types seems to indicate that no one starter shows a definite superiority, for all situations, over several factors.
![Page 3: Starting and Auxiliary Power Systems](https://reader033.vdocuments.mx/reader033/viewer/2022061204/547eee8db37959582b8b560d/html5/thumbnails/3.jpg)
Length of starting cycle – For military equipment. Starting time may be of primary importance. In addition, the speed with which the starter can accelerate the engine to idle speed will influence not only peak exhaust gas temperatures, but also the length of time the engine spends at these high starting temperatures.
![Page 4: Starting and Auxiliary Power Systems](https://reader033.vdocuments.mx/reader033/viewer/2022061204/547eee8db37959582b8b560d/html5/thumbnails/4.jpg)
Availability of starting power – Even small gas turbine engines require large amounts of either electric or pressure energy. Large engines require correspondingly more. Some starting systems are completely self-contained, while others require power from external sources. Many airplanes carry their own energy source in the form of a self-contained, small auxiliary gas turbine engine that produces electric and/or pressure energy. Power may also be taken from a running engine in multiengine installations.
![Page 5: Starting and Auxiliary Power Systems](https://reader033.vdocuments.mx/reader033/viewer/2022061204/547eee8db37959582b8b560d/html5/thumbnails/5.jpg)
Design features – Included in this area are such things as specific weight (pounds of starter weight of foot-pound of torque produced), simplicity, reliability, constant and maintainability.
![Page 6: Starting and Auxiliary Power Systems](https://reader033.vdocuments.mx/reader033/viewer/2022061204/547eee8db37959582b8b560d/html5/thumbnails/6.jpg)
THE FOLLOWING IS A LIST OF GAS TURBINE STARTERS
Electric motor starterElectric motor generator (starter-generator)Pneumatic of solid-propellant starterCartridge or solid propellant starter.Hydraulic motor starterLiquid monopropellantHand-crank starter
![Page 7: Starting and Auxiliary Power Systems](https://reader033.vdocuments.mx/reader033/viewer/2022061204/547eee8db37959582b8b560d/html5/thumbnails/7.jpg)
ELECTRIC MOTOR STARTER Electric motor starters are 28-V series-wound
electric motors, designed to provide high starting torque. Their use is limited to starting smaller engines because of the very large current drain (over 1000A for some models) and because they are relatively heavy for the amount of torque they produce. The starter includes an automatic jaw-meshing mechanism.
![Page 8: Starting and Auxiliary Power Systems](https://reader033.vdocuments.mx/reader033/viewer/2022061204/547eee8db37959582b8b560d/html5/thumbnails/8.jpg)
ELECTRIC MOTOR-GENERATOR (STARTER-GENERATOR)
Most small gas turbine engines, use a sarter-generator. This system has the advantage of being lighter than a separate starter and generator since a common armature is used, and it requires no engaging or reduction gear mechanism. The engine accessory section also requires one less gear.
![Page 9: Starting and Auxiliary Power Systems](https://reader033.vdocuments.mx/reader033/viewer/2022061204/547eee8db37959582b8b560d/html5/thumbnails/9.jpg)
AIR TURBINE STARTER Models of the air turbine starter are installed on the
Boing 720, 747, etc. Its primary advantage is its light weight (about 20 to 25 lbs) (9 to 11 kg) to torque ratio when compared with the electric motor and starter and starter-generator. The principal disadvantage is that it requires a supply of high-volume airflow of approximately 40 lb/min (18kg/min) at a pressure of about 50 psi. Source include compressed air from and auxiliary gas turbine carried on board the aircraft or maintained part of the airport facilities, compressed air bled from the other running engine(s), or compressed air from an air storage system.
![Page 10: Starting and Auxiliary Power Systems](https://reader033.vdocuments.mx/reader033/viewer/2022061204/547eee8db37959582b8b560d/html5/thumbnails/10.jpg)
CARTRIDGE OR SOLID-PROPELLANT STARTER
Originally, cartridge or solid-propellant starters were constructed to operate solely by means of high-pressure, high-temperature gas generated by the burning of a solid-propellant charge. Changes in the cartridge-type starter have added the additional capability of a starting with compressed air from an external source.
![Page 11: Starting and Auxiliary Power Systems](https://reader033.vdocuments.mx/reader033/viewer/2022061204/547eee8db37959582b8b560d/html5/thumbnails/11.jpg)
FUEL-AIR COMBUSTION STARTER
The fuel air-combustion starter is essentially a small gas turbine engine, minus its compressor. It is completely self-contained, as is the cartridge starter system, but unlike the preceding system, requires no additional components to function. All fuel, air, and electric power needed for operation are carried on the board aircraft.
![Page 12: Starting and Auxiliary Power Systems](https://reader033.vdocuments.mx/reader033/viewer/2022061204/547eee8db37959582b8b560d/html5/thumbnails/12.jpg)
GAS TURBINE STARTER The gas turbine starter is another completely
self-sufficient starting system. Relatively high power output is available for a comparatively low weight. The starter is actually a small, free-power turbine engine, complete with a gas-generator section containing a centrifugal compressor, combustion chamber, and turbine to drive the compressor. It also contains its own fuel control, starter, lubrication pump and system, and ignition system.
![Page 13: Starting and Auxiliary Power Systems](https://reader033.vdocuments.mx/reader033/viewer/2022061204/547eee8db37959582b8b560d/html5/thumbnails/13.jpg)
HYDRAULIC SYSTEM Hydraulic starting systems fall into two
categories Energy limited Power limited
![Page 14: Starting and Auxiliary Power Systems](https://reader033.vdocuments.mx/reader033/viewer/2022061204/547eee8db37959582b8b560d/html5/thumbnails/14.jpg)
ENERGY-LIMITED The energy-limited system uses a highly
pressurized accumulator and a large type, positive-displacement motor. Examples of other starting systems that are also energy-limited are the electric motor, when supplied from a battery, and the cartridge starter. The energy-limited system is desighned to complete the start in as short a time as possible in order to minimize the amount of stored energy required. The accumulator system is best suited to small engines up to 150hp (112kW).
![Page 15: Starting and Auxiliary Power Systems](https://reader033.vdocuments.mx/reader033/viewer/2022061204/547eee8db37959582b8b560d/html5/thumbnails/15.jpg)
POWER-LIMITED A power-limited system uses an auxiliary
power unit (sometimes a small gas turbine engine, which is itself starter by an energy limited system to drive a pump that supplies the correct amount of flow and pressure to a variable-displacement hydraulic starter motor. The variable-displacement motor permits high torque to be applied without exceeding the power limits of the main engine at starter cutoff speed.
![Page 16: Starting and Auxiliary Power Systems](https://reader033.vdocuments.mx/reader033/viewer/2022061204/547eee8db37959582b8b560d/html5/thumbnails/16.jpg)
LIQUID MONOPROPELLANT STARTER In this system a charge of liquid
monopropellant (a monopropellant fuel is one that requires no separate air supply to sustain combustion) is decomposed to produce the high energy has needed for turbine operation. Monopropellants that can be used include highly concentrated hydrogen peroxide, isopropyl nitrate, and hydrazine.
![Page 17: Starting and Auxiliary Power Systems](https://reader033.vdocuments.mx/reader033/viewer/2022061204/547eee8db37959582b8b560d/html5/thumbnails/17.jpg)
AIR-IMPINGEMENT STARTER In many ways the air-impingement starter
system is the simplest of all starter types, consisting essentially of nothing more than a duct. An air supply from either a running engine or a ground power unit is directed through a check valve onto the turbine blades (most commonly) or the centrifugal compressor.
![Page 18: Starting and Auxiliary Power Systems](https://reader033.vdocuments.mx/reader033/viewer/2022061204/547eee8db37959582b8b560d/html5/thumbnails/18.jpg)
HAND-CRANK STARTER The hand crank method of starting gas
turbine engines is, of course, limited to very small units, on the order of 50 to 100 hp. As the name implies, starting is accomplished by turning a hand crank, which through a series of gears, turns the engine to the self-sustaining rpm.
![Page 19: Starting and Auxiliary Power Systems](https://reader033.vdocuments.mx/reader033/viewer/2022061204/547eee8db37959582b8b560d/html5/thumbnails/19.jpg)
ADVANTAGES
![Page 20: Starting and Auxiliary Power Systems](https://reader033.vdocuments.mx/reader033/viewer/2022061204/547eee8db37959582b8b560d/html5/thumbnails/20.jpg)
ELECTRIC MOTOR Self-contained starts possible for small
engines Engine may be motored for short periods
without starter overheating
![Page 21: Starting and Auxiliary Power Systems](https://reader033.vdocuments.mx/reader033/viewer/2022061204/547eee8db37959582b8b560d/html5/thumbnails/21.jpg)
STARTER-GENERATOR One less accessory drive necessary No overrunning clutch, gearbox, or engaging
mechanism necessary Lighter than a single starter and generator Self-contained starts possible for small
engines.
![Page 22: Starting and Auxiliary Power Systems](https://reader033.vdocuments.mx/reader033/viewer/2022061204/547eee8db37959582b8b560d/html5/thumbnails/22.jpg)
AIR TURBINE STARTER High torque-to-weight ratio (5 to 10 times
higher than electric motor) Engine may be motored at low or high speed Can use air from a running engine
![Page 23: Starting and Auxiliary Power Systems](https://reader033.vdocuments.mx/reader033/viewer/2022061204/547eee8db37959582b8b560d/html5/thumbnails/23.jpg)
CARTRIDGE STARTER Self-contained starts possible for large
engines Very high torque-to-weight ratio Quick starts and gang possible for military
aircraft Automatic starts possible
![Page 24: Starting and Auxiliary Power Systems](https://reader033.vdocuments.mx/reader033/viewer/2022061204/547eee8db37959582b8b560d/html5/thumbnails/24.jpg)
FUEL-AIR COMBUSTION STARTER Completely self-contained High-torque-to-weight ratio Automatic stars possible Engine may be motored for short periods on
internal air supply at low rpm
![Page 25: Starting and Auxiliary Power Systems](https://reader033.vdocuments.mx/reader033/viewer/2022061204/547eee8db37959582b8b560d/html5/thumbnails/25.jpg)
GAS TURBINE STARTER Completely self-contained starts possible High torque-to-weight ratio Long periods of engine motoring possible
![Page 26: Starting and Auxiliary Power Systems](https://reader033.vdocuments.mx/reader033/viewer/2022061204/547eee8db37959582b8b560d/html5/thumbnails/26.jpg)
HYDRAULIC STARTER Compact in size Can be self-contained for smaller engines Can be adapted to function as a pump Relatively uncomplicated
![Page 27: Starting and Auxiliary Power Systems](https://reader033.vdocuments.mx/reader033/viewer/2022061204/547eee8db37959582b8b560d/html5/thumbnails/27.jpg)
MONOPROPELLANT STARTER High starting-torque-to-weight ratio
![Page 28: Starting and Auxiliary Power Systems](https://reader033.vdocuments.mx/reader033/viewer/2022061204/547eee8db37959582b8b560d/html5/thumbnails/28.jpg)
AIR-IMPINGEMENT Simplest of all types Can be used to motor engine, but only with
continuous air supply Extremely light Can use air from another running main
engine
![Page 29: Starting and Auxiliary Power Systems](https://reader033.vdocuments.mx/reader033/viewer/2022061204/547eee8db37959582b8b560d/html5/thumbnails/29.jpg)
HAND-CRANK STARTER Very reliable Independent of external power systems,
except muscle power Lightweight
![Page 30: Starting and Auxiliary Power Systems](https://reader033.vdocuments.mx/reader033/viewer/2022061204/547eee8db37959582b8b560d/html5/thumbnails/30.jpg)
DISADVANTAGES
![Page 31: Starting and Auxiliary Power Systems](https://reader033.vdocuments.mx/reader033/viewer/2022061204/547eee8db37959582b8b560d/html5/thumbnails/31.jpg)
ELECTRIC MOTOR Limited to starting small engines Relatively heavy for torque produced Reduction gears necessary Engaging mechanism necessary
![Page 32: Starting and Auxiliary Power Systems](https://reader033.vdocuments.mx/reader033/viewer/2022061204/547eee8db37959582b8b560d/html5/thumbnails/32.jpg)
STARTER-GENERATOR Limited to small engines Relatively heavy for torque produced when
operating as a starter
![Page 33: Starting and Auxiliary Power Systems](https://reader033.vdocuments.mx/reader033/viewer/2022061204/547eee8db37959582b8b560d/html5/thumbnails/33.jpg)
AIR TURBINE STARTER High-volume air supply required Gearbox needed with self-contained oil
supply Electrical connections and needed for speed
control
![Page 34: Starting and Auxiliary Power Systems](https://reader033.vdocuments.mx/reader033/viewer/2022061204/547eee8db37959582b8b560d/html5/thumbnails/34.jpg)
CARTRIDGE STARTER Cartridge needed for each start Gearbox, clutch, and oil system necessary No motoring possible for systems checkout
![Page 35: Starting and Auxiliary Power Systems](https://reader033.vdocuments.mx/reader033/viewer/2022061204/547eee8db37959582b8b560d/html5/thumbnails/35.jpg)
FUEL COMBUSTION STARTER Relatively complex Only two self-contained starts possible
![Page 36: Starting and Auxiliary Power Systems](https://reader033.vdocuments.mx/reader033/viewer/2022061204/547eee8db37959582b8b560d/html5/thumbnails/36.jpg)
GAS TURBINE STARTER
One of the most complex of starter types in that it requires its own starter, all of the systems of the main engine plus an overrunning clutch
![Page 37: Starting and Auxiliary Power Systems](https://reader033.vdocuments.mx/reader033/viewer/2022061204/547eee8db37959582b8b560d/html5/thumbnails/37.jpg)
HYDRAULIC SYSTEM Requires a high-volume air supply (3 to 5
times the pneumatic energy requirements of the air turbine starter)
![Page 38: Starting and Auxiliary Power Systems](https://reader033.vdocuments.mx/reader033/viewer/2022061204/547eee8db37959582b8b560d/html5/thumbnails/38.jpg)
HAND-CRANK STARTER Limited to very small engines Cranking handle must be stored
![Page 39: Starting and Auxiliary Power Systems](https://reader033.vdocuments.mx/reader033/viewer/2022061204/547eee8db37959582b8b560d/html5/thumbnails/39.jpg)
END.