rocket team: design package - web.nmsu.edu

ROCKET TEAM: DESIGN PACKAGE

New Mexico State University- Fall 2011

Facet 1 RECOGNITION AND QUANTIFICATION OF NEED

Market Demand

Recruitment is the most effective way to show high school students what a specific college is about. By traveling to prospective audiences, a school can sell itself on why they should choose as their place of higher education. By getting more students to attend that university, more funding can be given to the school, and companies will invest in the school for resources to further improve students’ experiences.

Many students are interested in hearing talks about the educational programs and the different types of majors available to them. In addition, they want to know the details of what these majors can do for them, especially in terms of acquiring jobs and careers; they want to know what kind of classes they will take and what work they will learn how to do in the future. Presentations and demonstrations are both good ways to show this; for the NMSU College of Engineering and the Mechanical and Aerospace Department, student-created demonstrations of projects can be shown to prospective students concerning what type of classes, research, and work they can do in college. Undergraduate research and Senior Design Capstone projects are among the best possible demonstration units to show students what mechanical and aerospace engineers do.

These projects could also be used for future research and laboratory experiments as well, especially in the field of aerospace engineering. This project could be used to experimentally check researched data in many areas related to fluid dynamics, propulsions, controls, and other aerospace-related subjects. Research conducted using these projects can further the prestige of the department. By solving new and unknown problems, students will have the opportunity to write and submit research into journals, gain first hand experimental and research experience, and the understanding of how research is conducted amongst engineers.

The reasons above show how important beginning-level research projects are to the

students, the department, the academic world, and the recruitment of future students. By

carefully determining what type of research can be used as a recruitment tool, student

research projects and laboratory experiments can be used to conduct academic research

and current students can be assigned to projects that fulfill their needs.



Solution Assessment Currently, southern New Mexico has become a very important location in the field of

Aerospace Engineering. New Mexico State University has opened an undergraduate program in the field of Aerospace Engineering in 2006 and a graduate program for Aerospace Engineering in 2011. Spaceport America was opened in 2006, 45 miles north of New Mexico State University. The spaceport will be the eventual launch site of White Knight Two, designed and built by Virgin Galactic, which is the first privately-owned suborbital spacecraft. These developments have led to a growth of the private industry in Aerospace Engineering in the southern New Mexico area. Thus, research projects given to NMSU Engineering students should be related to the field of Aerospace Engineering in particular propulsions.

Rockets have always been a fascination of the American people and scientists. With the association of the history of rocketry in New Mexico with the current growth of rocketry in New Mexico, a project that would appeal to local students and that be used academically would be a rocket-based project. Since rockets come in all sorts of shapes, sizes, configurations, and types, the possible list of projects is endless. However, to meet the needs of demonstration and research requirements, many projects would not qualify for the stated needs. The following deductions can be made from the needs stated above.

The project needs to be portable.

The project needs to be set up easily for engineers.

The project needs to have interchangeable parts.

The project can be set to a fully-automated control.

The project needs to be set up with the ability of accurately acquiring data.

From NASA and NMSU engineers, the idea to make a joint project that can fulfill the

requirements above was born. The idea permeated into a rocket-based project that can be

used by NASA and NMSU for recruitment, laboratory testing, and experimental design

processes. NASA has interest in this for its educational outreach programs, and evaluating

students at the collegiate level by using the project for research and experimentation. The

NASA Mission Directorate that supports this research is the Exploration Systems, which

encourages a diverse range of students to become involved in the science and technology

areas relevant to NASA.

After collaboration from NMSU, NASA, and speaking with Dr. Ed Conley of the NMSU

MAE department, the hybrid rocket project was born. The idea of this project is to create a

compelling hands-on facility, which will give an Aerospace Engineering (design/build/test)

experience. This is to be coupled with immersion in the instrumentation and information

management systems that will prevail in the new century. Specifically, this small, portable

Hybrid Rocket Test Stand instrumented will offer what’s known as ‘discovery-learning’

designed to maximize the ever more limited time and resources that engineering students

can devote to the real world.



Along with this project idea came requirements and guidelines set by NASA in order to

create a device worthy of safely having the ability to enlighten and capture the eye of

prospective students. These requirements are listed below from 1 to 24.

1. CPD shall be easily portable. Able to move from a car/truck to a classroom via one

person. Envision a suitcase size device. 2. CPD Combustion products shall not be toxic, nasally overbearing, or visually

disturbing (i.e. not much smoke, don’t want to set alarms off) 3. CPD shall be able to be set up in no more than 15 minutes. 4. CPD shall have the following instrumentation: Thrust Measurement, Oxidizer flow,

Chamber Pressure, Gas Oxygen Temperature, Nozzle Exit Temperature, Battery voltage.

5. CPD shall be able to perform a preset thrust profile (i.e. Oxidizer flow automatically adjustable).

6. All CPD components shall be able to be repaired or replaced in the field. 7. All CPD instrumentation shall be able to be replaced with spare in the field. 8. All CPD instrumentation data will be displayed on a flat LCD screen. 9. CPD data from firings shall be saved and easily retrieved. 10. Activation and Control of CPD shall be automatically with provision for manual

control. 11. The CPD shall have a reusable in place ignition system. 12. CPD shall be able to fire continuously for duration greater than 20 seconds. 13. CPD shall be able to do at minimum 4 test firings in one hour. 14. The CPD controls shall assess readiness for operation (eg. Electrical power; Igniter

continuity; oxidizer pressure; article temp for restart). 15. CPD demonstrator shall be able to present a pre-recorded data of actual rocket

testing on its LCD screen. 16. CPD shall operate via graphic user interface. 17. CPD shall display propulsion graphically. Showing discharge changing in respect to

fuel and oxidizer changes. 18. CPD shall graphically show the relationship between all propulsion variables. 19. Both recorded data and video shall be time-stamped. 20. The post-test data shall be time-aligned to a start event. 21. CPD shall have an Emergency Shut-Off capability which will remove the oxygen

supply from the device. 22. Data Display shall not interfere with data acquisition and recording operations. 23. CPD shall be capable of firing horizontally. 24. CPD design team shall provide end-to-end system uncertainty calculations in terms

of percentage of full scale ranges.



Budgetary Parameters

The budget for the hybrid rocket project was provided by NASA and the NMSU MAE

department. The initial budget for the current semester is about $1,500. Before this project

was given to the Capstone team, many areas of the project were already worked on by

individual students with the guidance of Dr. Conley.

The following list best describes the budget parameters set forth for this project:

Pipe Adapters

Allen Screws

Load Cell

Flow Meter



Facet 2 PROBLEM DEFINITION

Design Objective

The overall objective of this project is to develop a hybrid rocket and test stand

instrumented with any number and types of modern sensors. The design of this hybrid

rocket and test stand is to be small and portable (suitcase size); the basic apparatus will be

used for demonstrations in rocket propulsion. The design will also include all of the needed

hardware to operate the hybrid rocket unit (with the exception of the external oxygen

tank). It is to be equipped with chamber pressure, a flow meter to measure the amount of

oxygen flow, and thrust sensors at a minimum, making it compatible with a laptop analog

card. The design of this project will also include making the correlation between the

rocket’s thrust and its size, the appropriate transducers (physical size, resolution, range,

and cost), the ease of setup, and its portability. The data acquisition and analysis software

includes LabVIEW and for any general physical modeling, Unigraphics software will be

used. The design objective was formed by NASA and Dr. Conley to fit the required needs of

the project. Since the project was reduced to a specific hybrid rocket setup, the needs could

be even further refined.

Design Constraints Restrictions will apply in the design of the portable hybrid rocket unit. They will be

defined into the following categories: Budget

Funding was provided by NASA, but has been used up by previous researchers working with Dr. Conley. The money was used to purchase needed hardware and testing equipment for the DAQ systems of the hybrid rocket. Time

Time proved to be a constraint for the overall objective of this project. Previous students have contributed research to this project since Spring 2010, and were only able to research instruments for DAQ use, materials for the rocket design, and create the engine for the rocket, which was redesigned this semester. Since this has been an ongoing project, each semester has been given a set goal to accomplish. The Spring 2011 Capstone team’s main goal was to finish creating the rocket engine. This included finding the right type of fuel, finding the right material to make it out of, creating it a compact size, and making an ignition system. The Fall 2011 Capstone team was given the task to better the equipment used. A few examples include making the rocket lighter, compacting the Data Acquisition System, and enlarging the test stand to the length of the rocket to eliminate more error in the data. To accomplish these goals the Capstone Design Team was split up into sub-



groups. Each of these sub-groups has allotted a great amount of time to each section of the project. Most of the time has been focused on the electrical portion of this project. Legality and Safety

The legality of this project is closely associated with the safety aspects of the rocket, and thus the constraints from these two are associated. When this project is being used as either a demonstration device or an experimental device, the safety of the operators must be ensured. This also pertains to those who are observing the procedure while the hybrid rocket unit is being used. One requirement that constrains operators using this device is reading and understanding the safety guide and manual for the hybrid rocket unit. The manual that is to be typed up by the researchers working on this project will accompany the rocket to all of its locations. Any operator who plans to use the rocket for any purpose must first read the manual and follow the procedure given on how to run a test or demonstration. The manual will include the correct assembly procedure of the unit for each use (experimental setup and demonstration setup). It will ensure assembly components are checked and re-checked to ensure they are connected correctly. It will appropriate operating area definitions for each type of setup, and define limitations on test length, mass flow control rate, and thrust. Proper attire, including safety equipment, will be detailed in the manual, as will correct testing and disassembly procedures. Operators who do not read the manual will endanger themselves, co-workers, and spectators of the hybrid rocket unit, and can be held liable for legal damages. Personnel

Personnel constraints will break down into the following categories: Knowledge

Team members of the hybrid rocket unit project had to expand their knowledge base in the areas of hybrid rockets, LabVIEW and DAQ systems, and refresh the knowledge base in areas of statics, thermodynamics, and fluid dynamics.

Safety The safety of the hybrid rocket project is referenced in the Safety Manual. The Safety Manual is located in the Detailed Design section of the document.

Teamwork The ability for the team to adhere to a team contract, which includes regularly attending meetings, voicing opinions and contributing ideas to the group, completing assigned tasks, and informing the group in a timely manner of the details of the assigned work.



Material Properties and Availability Material property and availability also go hand in hand with the team’s budget. Most

of the material needed for this semester had been previously bought and include the fuel grain, Teflon, flow meter and the DAQ instrument devices. Other materials such as the steel and aluminum have been supplied by NMSU. The materials that presented any issues during this semester include the pipe adapters and the flow meter. The pipe adapters proved to be hard to find because of the different types of threads on the chosen adapters. These types of fittings are special ordered and are not found in stores. The flow meter can only be ordered online and was shipped from the National Instruments Company. The flow took a few months to program. Manufacturability

The NMSU Student Project Workshop is open for approximately 9-10 hours a day, five days a week. Thus, the accessibility to manufacture parts is relatively easy. The parts needed to be manufactured include the rocket which is made out of steel and aluminum plates. The other two parts manufactured includes the rocket test stand, which is made out of aluminum, and the nozzle made out of carbon. Since, the machine shop does not have specific carbon-cutting tools, a graduate student allowed the nozzles to be created at his own shop. Listed in the Design Specifications section is a description of each.



Design Specifications The requirements of the design were defined by NASA and Dr. Conley, which are

stated above. Previous researchers associated with Dr. Conley have derived design specifications to direct the project in a specific direction to meet the project needs. The specifications they have made were in the areas of DAQ instruments, the hybrid rocket fuel grain and motor assembly, use of oxygen as liquid fuel, the frictionless slider, and ignition system. The following outline defines the specifications that the Capstone Hybrid Rocket team have followed in order to meet the goals:

Portability Size of carrying case will be approximately the size of a typical to large shoulder-carried briefcase. The case will carry the hybrid rocket motor, testing instruments, and hardware assembly.

Test Instruments The areas to be experimentally analyzed are the thrust, oxygen flow, and the back pressure of the rocket unit. The thrust is calculated by using a system that utilizes load cells, the oxygen flow is measured using a power supply, the back pressure is measured using a pressure transducer, and all the testing devices use a DAQ National Instruments system. The LabVIEW program is used to visually show live data and record it to be used in analytical calculations and analysis of the rocket.

Hardware Hardware was machined as necessary from scrap parts or purchased parts. The hardware was used to secure either the rocket itself, the testing instruments, or the plumbing into place.

Plumbing A plumbing system was used to transport oxygen from its tank to the rocket. The parts of the plumbing system are oxygen cleaned and air tight. The plumbing system also incorporates a mass-flow control unit, as well as a solenoid and needle valve for safety purposes.



Facet 3 CONCEPT DEVELOPMENT

Brainstorming Techniques

From the desired project needs and specifications, previous researchers with Dr.

Conley brainstormed concepts that would meet the needs of the hybrid rocket project. The

concepts associated with the hybrid rocket will be broken down into four categories:

nozzle, hardware, plumbing, and DAQ systems. Each of these areas has a specific input into

the project, and will be broken down into separate engineering tasks. Each of the areas of

concept design will have their own needs and specifications derived or allocated from the

needs and specifications of the overall project. The team/engineers working within each

individual concept will first plan out their systems in general for review, verification, and

validation. The concept designs will have the following needs and requirements.

Hardware

The purpose of the hardware concept development is to meet the needs of

securing the hybrid rocket motor, the rocket test stand; test instruments, plumbing

system, and any other needed devices in a predetermined layout. The layout will be

determined after input from all the concept developments are condensed into one

idea. Hardware will be either purchased or designed and machined either by team

engineers or specialists. The material for the hardware will either come from the

scraps from the NMSU Student Project Center or be purchased from online retailers.

Designs will be drawn and documented in Unigraphics to be reviewed by the team

and Lead Engineer; if approved, the parts will be machined or purchased. Design

drawings are in the Detailed Design section of the document.

Plumbing

The purpose of the plumbing concept development is to meet the needs of

providing the liquid fuel from its tank to the hybrid rocket in a safe and controlled

way. As mentioned above, the liquid fuel for this project will be oxygen. Devices that

will be needed for this system will include a pressure regulator, solenoid valve,

hoses, adapters, a needle valve, pipe connectors, Teflon tape, swivel adapters, and a

mass-flow control unit. The nature of these parts will be to work with oxygen, so the

preference is to have them suited for oxygen use or to have them oxygen-cleaned.

This means that the parts will have to be purchased instead of manufactured. The



design of the flow system needs to have checks to control the flow for safety

purpose. This will be accounted for by having the liquid fuel flow from the tank first

enter through the solenoid valve, to the mass-flow control unit and from there to the

needle valve. This theory will restrict the order of the parts of the plumbing system.

The specifics of the plumbing system will be discussed further in the Preliminary

Design Section.

Nozzle Since the nozzle is able to change the thrust depending on how it is made, the

nozzle will need to be made up to certain standards set by Dr. Conley. These standards that Dr. Conley has set are given in a binder. From these standards the nozzle is required to produce a shock diamond that can be seen at the end of the nozzle.

Data Acquisition Systems

The Data Acquisition (DAQ) Concept Design system will need to govern what

data will be recorded, how it will be recorded, and for how long/how often.

Described from the needs above, the thrust, oxygen flow, and back pressure are to

be measured from the hybrid rocket system during use to determine scientific

characteristics that can be used to describe the rocket. The specific instruments that

will be used to acquire the data for each system are as follows: a load cell for thrust,

power connection to the flow meter, and a pressure transducer for back pressure.

As needed, hardware or plumbing will be manufactured or purchased to be able to

correctly acquire the data as efficiently as possible. A combination between the

hardware concept design and the DAQ concept design will create the setup in which

the load cell can be properly arranged to acquire the data. As well as a combination

between the plumbing and DAQ concept design will create a setup for the pressure

transducer. The flow meter will also be connected to the DAQ along with a power

supply. Each of the testing instruments will be connected to one DAQ module, this

will allow for both an input and output signal to each device. This DAQ module is a

National Instrument box which will allow for a simple connection and is more

compact. The LabVIEW program records data at 2000 Hz, shows the output signals

graphically and through visual dials, it exports data to a text file, and ignites the

ignition system that starts the rocket motor.



Facet 4 FEASIBILITY ASSESMENT

As this is a continuing project, all items assessed include redesigns and re-fabrications, along with possible re-direction ideas.

Below is a list and description of five (5) items, followed by an analysis consisting of eight (8) guiding questions, derived from four (4) categories: technical, economic, scheduling, and marketing.

The questions examine the impact of each item’s implementation by assigning it a score of 1 (least beneficial), 2 (fairly beneficial), or 3 (most beneficial).

The scoring system applied to these impacts will assist in ranking the importance of the new items and ideas, allowing the quantification of the value of each.

Item/Idea Descriptions

Item 1: Re-fabrication of the Rocket Engine Injector Base

The current rocket engine is made primarily or steel giving it a significantly high weight. The re-fabricated of the injector base with lightweight aluminum is sought to achieve a lower overall weight.

Item 2: Redesign and Re-fabrication of the Engine Nozzle

Currently the nozzle installed in the rocket engine is not manufactured to spec and will not allow for maximum efficiency of the engine. A complete redesign and re-fabrication of multiple nozzles is required to achieve the best efficiency of the engine at set operational parameters.

Item 3: Re-fabrication of Test Stand

The current test stand is equipped with inadequate bearings that do not allow for purely one directional motion and the top plate of the test stand is not properly machined. These issues allow the engine to create additional unwanted motion and erroneous data from the load cell. A re-fabrication of the test stand is necessary to adequately house the redesigned rocket engine and alleviate much of the erroneous data acquired during testing.



Item 4: Electronics and Controls

To date; the operation and control of this system is manually completed. The system is ultimately required to operate autonomously with minimum human interaction. The redesign and re-fabrication of control electronics is sought to achieve this requirement set forth by NASA.

Item 5: Data Handling and Calculation of Results

The implementation of a filter and a data output system is required to allow for accurate and timely data handling and result calculation. This will allow for less down time between testing phases and more timely results giving way to quicker analyses of current problems.



Item Analysis

Question Category: Technical

Question 1: Is this item capable of producing a noticeable increase in performance?

Scoring System:

1: Least Beneficial - not capable of producing any increase in performance

2: Fairly Beneficial - capable of producing a moderate increase in performance

3: Most Beneficial - capable of producing a significant increase in performance

1 Point 2 Points 3 Points

Rocket Injector Base

X

Rocket Engine Nozzle

X

Test Stand Re-fabrication

X

Electronics and Controls

X

Data Handling and Results Calculation

X



Question Category: Economic

Question 2: Does this item require less material?

Scoring System:

1: Least Beneficial - requires an excessive amount of materials

2: Fairly Beneficial - requires more material than alternatives

3: Most Beneficial - requires a reasonable amount of materials



X


X


X


X


X




Question 3: Is it necessary to use special equipment for this Item?

Scoring System:

1: Least Beneficial - requires expensive specialty equipment

2: Fairly Beneficial - requires the use of some tools that may be outsourced for a reasonable

price

3: Most Beneficial - requires the use of standard hand tools or no tools at all



X


X


X


X


X




Question 4: Are the required materials expensive?

Scoring System: 1: Least Beneficial - requires materials that are out of the clients budget range 2: Fairly Beneficial - requires materials that are just within the clients budget range 3: Most Beneficial - requires materials that are well within the clients budget range



X


X


X


X


X



Question Category: Scheduling

Question 5: Is there enough time to complete this item? Scoring System:

1: Least Beneficial - requires more time than is allotted 2: Fairly Beneficial - requires more time than allotted solely to complete testing

3: Most Beneficial - will be completed within the allotted time and have ample time for testing



X


X


X


X


X



Question Category: Scheduling

Question 6: Will this item require outside help to complete? Scoring System:

1: Least Beneficial - requires an excessive amount of outsourcing 2: Fairly Beneficial - requires some outsourcing

3: Most Beneficial - requires minimal to no consultation to complete



X


X


X


X


X



Question Category: Marketing

Question 7: Is this system marketable with the new item? Scoring System:

1: Least Beneficial - amount of power gained does not warrant the change 2: Fairly Beneficial - amount of power gained is somewhat attractive

3: Most Beneficial - amount of power gained is very attractive and offers a swift ROI (return on investment).



X


X


X


X


X



Question Type: Marketing

Question 8: Does this system require a client with high investment resources? Scoring System:

1: Least Beneficial - requires a client with substantial financial resources 2: Fairly Beneficial - requires a client with moderate financial resources

3: Most Beneficial - will be suitable for a client with little to no financial resources



X


X


X


X


X



Item Impacts

Q1 Q2 Q3 Q4 Q5 Q6 Q7 Q8 Total


1 3 1 3 3 3 3 2 19


3 3 1 3 3 3 3 2 21


2 3 1 3 3 3 2 2 19


2 2 2 3 2 2 2 2 17


1 2 2 3 2 2 2 2 16

With the impacts above it was decided that all items were to be addressed this

semester. However the electronic portions would be allowed to continue past the scope of

one semester.



Facet 5 PRELIMINARY DESIGN

Design 3

The focus of the previous semesters work was primarily on testing with mobility

being further out of scope. From the results of that testing it was concluded that the first

design lacked the sensitivity needed to record accurate thrust data. The second design

acquired more accurate data but was crude and far from mobile. With that in mind, the

goal of the third redesign was to fabricate a test stand that could be easily transportable

and take meaningful data measurements.

Apparatus

The rocket motor has undergone two minor modifications in design 3. First the

inlet base was remanufactured to be lighter and slightly smaller. Thermocouple

measurements from the previous semester provided the insight needed to make this

decision. The new part was manufactured from aluminum and is a quarter inch thinner

than the old. Previous ignition ports that are no longer used were also left out of the new

component. All other geometric entities of the part remained constant. The nozzle used in

previous semester’s tests was fabricated based off drawings provided from NASA in the

student project center at NMSU. However the student project center lacked sufficient tools

to precisely produce the specifications. This semester an outside machine shop was

utilized to improve nozzle performance. The geometry of the nozzle also changed after

research was conducted in nozzle theory. The diverging section was tapered to 30 and the

throat of the nozzle was tightened to an eighth of an inch. More advances in the nozzle

design under way along with more testing.

Design 3 incorporated a bending beam load cell for taking thrust measurements.

Initially load cells used in measuring the thrust of the hybrid rocket were oversized.

Therefore with the third design came the most sensitive load cell thus far. The bending

beam load cell used at the beginning stages of design 3 had a working range of 5lbs.

However mid semester that load cell became non-functional and required replacement.

This gave an opportunity to decrease the operating range once again. This in return

increased the sensitivity. The new load cell has a working range of 600 grams or

approximately 1.3 lbs. This load cell was mounted directly underneath the inlet end of the

rocket motor. The opposite end was held in place by pinned connection. This pinned

support restricted translation in the vertical and transverse direction, but allowed for



translation in the axial direction. With these constraints in place the rocket was able to

produce thrust in the axial direction causing a force to be placed on the load cell. Pressure

data was taken in the same fashion as design 1 and 2.

In these designs the calibration for the testing instruments became key in making

sure the changes in voltage of the instruments actually represent what is really changing in

force, pressure, or temperature. This was done through calibration tests, with the load cell

being the main device that was calibrated.

Figure 1 and 2: Left: Side view of rocket and test stand. Right: Isometric view of rocket and test stand assembly. In both views the pinned supports can be seen on the right side, underneath the nozzle end, and the load cell can be seen on the right side of the test stand under the inlet side of the motor.

The ignition system has been notoriously difficult to work with. As a result a more

reliable solution was sought out in this design. The new system utilizes fuses that ignite

when electrically charged. Each fuse is Halliburton welded into a 3/8”NPT to ¼”PEX

adapter in order to create an air tight seal. The fuse adapter combination could then be

screwed directly into the plumbing assembly. This configuration placed the fuses right into

the back of the combustion section of the rocket. The fuses could then be ignited when

charged with a 12Vdc battery. This method has proven to be very reliable and incorporated

only a small set up procedure.



Safety in the third design has also been revised. This would be the first design to

incorporate an automatic shutdown switch. To do so, a solenoid valve was inserted into the

plumbing system. When electrically charged the solenoid valve is opened and allows the

oxygen to flow into the rocket motor. The switch that provides power to the solenoid valve

has a latch when pressed action, therefore the automatic shutdown switch must be pressed

for the entire duration of the test. Once the switch is released the solenoid valve loses

charge and cuts the flow of oxygen to the rocket. Efforts were also made to integrate the

ignition system with the cutoff switch. Ideally the system will fire with the initial pressing

of the shutdown switch and terminate when the switch is released.

The mass flow controller used in design 1 and 2 is also incorporated in the current

setup. The controller function has yet to be fully integrated because of difficulties

presented with programming the instrumentation. Rather the mass flow controller has

been used as a gauge by providing measurements on flow rate. A second more easily

programmable mass flow controller has been ordered at the beginning of the fall semester

but has yet to arrive. Design 2 Drawings may be seen on the following pages in the Spring

2011 section. The overall rocket and plumbing assembly for the Fall 2011 semester can be

seen in Figure 5.

The DAQ and control system were proven to be the major priority of this Fall 2011

semester. The idea for this system is to control the ignition switch, pressure transducer,

oxygen flow, the load cell, and any other device needed and or wanted. Although, the same

idea is the same as the previous semester the setup has changed and is more compact.

Instead of each device having its own module inserted into a chassis unit and having a

power supply, the unit for this semester still has a power supply but has only one module

that connects all of the devices and connects to a computer through a USB device. Just as

before the program that allows the data to be collected and that will control the system is

LabVIEW.

The LabVIEW Program was designed to interpret data from one load cell, one

pressure transducer, and the oxygen flow rate. The LabVIEW layout below shows the input

from the strain gauge, voltage form the transducer, and the oxygen flow unit running into a

sample clock. The clock tracks the time data and allows the user to set the amount of data

taken per time unit as desired. The timed data is then run into a loop that activates at a

button push and begins to record the data. The data is then exported to a waveform file and

converted in an excel spreadsheet for data interpretation and interpolation. In Figures 3

and 4 the Front Panel and Block Diagram of LabVIEW are shown from this semester.



Figure 3: Front Panel

Figure 4: Block Diagram



Since this is a continuation project and it is still in the process of improving everything is subject to change. For this semester procedures are still followed just at a more compact level. Shown below in Figure 5 is the final assembly of this Fall 2011 semester. The main objective of this design is reducing the amount of oxygen based hoses in order to make the plumbing more compact. In this set up the safety factor played a major role as mentioned above.

Figure 5: Rocket and Plumbing Assembly



Facet 6 PROJECT AND DATA ANALYSIS

Project Analysis

Throughout the current semester many portions of this project have been completed. The redesign of the before mentioned items (Facet 4) have been accomplished. The integration of complete electronic controls is still under way due to their complicated nature and constantly changing technology. The current state of the test stand, rocket engine, and electronics are shown below.

Figure 1 : Rocket Test Stand with a platform Figure 2 : Rocket motor consisting of fuel grain and attached load cell on the left side of the stand. to the ignition system and pressure transducer.

Figure 3: Electrical setup with bread board which connects the power supply to the flow meter, pressure transducer, solenoid valve, and load cell.



Figure 4: Complete assembly including rocket motor, test stand, plumbing, and

the electrical setup.

As seen above the test stand and rocket engine have been manufactured to

completion and are currently in working order. The electronics currently control the oxidizer flow to the engine along with data handling and filtering. These subsystems are continually changing to allow for increasingly better and cleaner results. The integration of an electronically controlled ignition subsystem along with more sophisticated data handling hardware and software is currently underway. Approximately four tests have been completed and logged with the current system with acceptable results. A picture of the system while under test situation is shown below.

For every test during this Fall 2011 semester, a test log was kept and an analysis of the data was ran using Excel. Shown below are the test logs for each test and the data collected.



Data Analysis Test 1



For this first test analysis of the results were not essential. This test consisted mostly of testing the nozzle and making sure the pressure transducer’s wires were connected to the breadboard correctly. From the graph above it is seen that no satisfactory data was gathered, meaning the wire connections were not correctly assembled.



Test 2



Test 3



For both the second and third tests the results proved to be satisfactory. Both tests measured the amount of pressure entering the combustion chamber, the oxygen leaving the flow meter, and the amount of thrust the rocket motor produces. Described below are the results for each test. Test Two:

The second test was set at a low pressure which read at an average of 5.5 psi. This produced a thrust of 0.6N. The graph for the oxygen flow showed that the oxygen remained constant from the beginning of the test until the oxygen was shut off. Test Three:

For the third test the oxygen flow was set at a higher rate than test two causing the

average pressure to read at about 8.2 psi. The average thrust measured followed the same trend as the pressure and read at about 0.8N. The graph for the oxygen flow followed the same inclination as test two.

From these results it is concluded that all devices are properly functioning and

synchronized with each other.



Facet 7 DETAILED DESIGNS AND TEST PROCEDURE

Comprehensive Drawing Packages

The following are comprehensive drawings of manufactured parts used in the experiments.



Hybrid Rocket Test Procedure

Pre-Test Check

1. Ensure rocket is completely assembled off of test stand

2. Ensure test stand and all hardware is secured to the base

3. Ensure all oxidizer lines are secure and free from leaks

4. Secure rocket to test stand

5. Ensure all data acquisition hardware is present and free of shorts, crosstalk, etc.

6. Designate person in charge of fire safety (extinguisher) and test recorder

7. Designate person in charge of oxygen shutoff switch

8. Designate person in charge of time clock operation

9. Complete individual component checks (DAQ, oxidizer, electronics, etc.)

10. Ensure test environment is open and well ventilated

11. Perform final safety check

Test Procedure

1. Start oxygen flow and set pressure, allow to reach equilibrium

2. Record initial oxygen flow parameters

3. Begin data acquisition

4. Ignite and start test clock

5. Commence throttling sequence until optimal pressure is obtained

6. Maintain optimal pressure throughout test

7. Record throttled oxygen parameters

8. Throttle down and disengage oxidizer

9. Complete data acquisition

10. Save data

11. Complete test log

rocket team: design package - web.nmsu.edu

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