Liquid-Fuel Rocket Motor Test System

ME 493 Final Report – Year 2015

Advisor: Dr. derek tretheway

TEAM MEMBERS: Adam Kiss

Dylan Stephens

Gene Baump

Jason Schrader

Jason Snyder

Samuel Stewart

SPONSOR: Portland State Aerospace Society

Executive Summary

The Portland State Aerospace Society, PSAS, is a student club established in 1997 at Portland State University, building and launching amateur rockets and designing other rocket systems at ultra-low costs. Currently, the rockets that are launched by the club are powered by a solid-fuel, commercially purchased rocket motor. This has been a convenient option for the club to make the launches successful, as they are relatively inexpensive and readily available.

However, with a goal of sending a rocket beyond the Karman Line, a design change in the propulsion of the rocket is required, as the Karman Line lies 100 kilometers above the surface of the earth and marks the boundary between the atmosphere and space. To reach this boundary, the rocket’s propulsion of a solid-fuel motor will no longer work. Therefore, a change to a liquid-fuel mixture powered motor is required. This is due to the additional weight of the motor needed to get the rocket out of the atmosphere.

When building a custom rocket motor, it is more than just machining a body, adding the fuel and oxidizer, and letting the motor propel the rocket without putting the motor under significant and sufficient testing. The testing includes measuring the thrust output of the given fuel-oxidizer mixture, the pressures and temperatures generated in the combustion chamber of the motor, and keeping the overall size of the stand structure within a size that is transportable in the bed of a pickup truck and light enough that two persons can maneuver it accordingly.

Once the system is built and completed, it will need to undergo several testing events to ensure that the plumbing system operates as intended with no leaks and at the correct pressures, and the load cells will need to be verified that they are measuring the strain of the material correctly.

Table of ContentsIntroduction 1

Background 1

Mission Statement 2

Main Design Requirements 2

Top-Level Alternative Designs 2

Final Design 4

Structural 4

Plumbing 6

Design Evaluation 7

Evaluation for Structural Design and Integrity 7

Evaluation for Function and Performance 8

Evaluation for Cost and Financial Performance9

Evaluation for Assembly and Transport 9

Evaluation for Manufacturing and Maintenance 10

Recommendations 11

Conclusion 11

Appendix A: Complete PDS I

Appendix B: FEA Results on Initial Designs III

Appendix C: Plumbing and Oxidizer Selection V

Appendix D: Bill of Materials and Costing VI

Appendix E: CAD Drawing for Load CellVII

Introduction

The deliverable product to the sponsor for this project is a fully self-contained test system that the sponsor, Portland State Aeronautics Society (PSAS), will be able to use for testing liquid-fuel rocket motors for their amateur-class rockets. Currently, there are no off-the-shelf options for the sponsor to purchase for their testing needs, and those that exist as permanent fixtures are enormously expensive to build and require a dedicated location for their usage. By designing and building this test stand, it provides the necessary means for the sponsor to grow their program and goal of being the first university to send a rocket beyond the Earth’s atmosphere and into space.

Background

The Portland State Aerospace Society is a student run and managed rocket club that was established in 1997. Presently, all rockets that are launched by the club are powered by commercially available solid-fuel rocket motors. These types of motors do not have the capabilities to send a rocket to space, as the weight of the number of motors needed exceed the thrust output of the combination of the motors. Therefore, the club, who is also the sponsor, has opted to design a motor that is powered by a liquid fuel and oxidizer combination. This change from solid-fuel motors has 3 major benefits to the club: 1.) a single motor is used to send the rocket to space, reducing costs per launch, 2.) the motor now has a throttle and therefore several different thrust outputs for a single motor design are available, and 3.) the motor is usable for more than a single launch, unlike the solid-fuel motors as they are by design a single-use item.

In order to design the motor so it operates successfully and with a high degree of certainty and reliability, it is essential that static tests be performed on the prototype before being used in the airframe of the rocket

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or near the flight control components. As such, the sponsor has determined that the stand needs to be an all-inclusive testing system, capable of not only holding the motor, but measuring selected outputs such as thrust, combustion temperatures and pressures, as well as the flow rates of the fuel and oxidizer being delivered to the motor. The product of this project will then give the sponsor the device they need to conduct the necessary tests to ensure a correct and safe configuration for the rocket motor.

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Mission Statement

The mission of this project is to build a testing system capable of holding and measuring outputs of the liquid-fuel motor, compact and self-contained in design and operation so as to be transportable and operated by two persons. The system is designed in such a way as to guard against damage and injury to surrounding environments and personnel, and be built in a way that if a failure does occur, affected components or systems are easily replaceable.

Main Design Requirements

The sponsor of the test system project, PSAS, had several requirement that they wanted in the finished product. The complete PDS matrix is provided in Table A1 in Appendix A, but a few of the important design requirements include:

Maneuverable by two persons Able to be set up in less than two hours All operations performed remotely Safely test and measure thrust output up to 10-kN Contains a failsafe that renders the system inoperable for safety and

maintenance

For each design iteration, we applied the requirements and preferences via a matrix to the particular design and considered the pros and the cons if the design. Through this process we were able to settle on one particular design that met a majority of the requirements, and the ones that were not met, we informed the sponsor to get their approval before continuing on with the project.

Top-Level Alternative Designs

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During the brainstorming sessions, several different design ideas were given consideration and evaluation to see the feasibility of the concept and if the design would meet the requirements of the sponsor. One of the critical points of interest in the structural design is the orientation of the nozzle. There are three main orientations: nozzle-up, nozzle-down, and nozzle-horizontal. The nozzle orientation indicates the direction the exhaust stream flows out of the motor nozzle relative to the ground.

The nozzle-up orientation would be the easiest to work around as the ground is the support against which the thrust of the motor works against. However, this particular orientation has one significant drawback; the oxidizer potentially will pool in the combustion chamber, which carries an enormous risk of generating a catastrophic explosion if it were to ignite. Based on this risk the team and the sponsor decided this would not be a viable option, even though it would be easy.

The nozzle-down orientation is the most preferable as it models how the motor is mounted in the airframe of the rocket. The drawback to this configuration is the amount of heat rejection capability needed to adequately deal with the exhaust gas temperatures. The team also discontinued with this concept when the calculations for the heat generated was on the order of tens of mega-Watts of heat, requiring hundreds of thousands of liters of water to cool sufficiently as not to destroy the stand or surrounding area immediately.

For the initial design concept for the horizontal nozzle-horizontal orientation, we came up with a sled to which the motor would be mounted. The design, shown in Figure 1, did not incorporate the tanks within the structure itself, and therefore didn’t meet the sponsor’s requirement for self-containment.

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The PDS was the tool in which each design was measured against to determine whether it would be a useful and buildable design. For the different iterations of the stand with this orientation, Finite Element Analysis, FEA, was done on each design. This was completed to see how the stand is predicted to perform under the loading conditions and met the sponsor’s requirement on the stresses developed.

We also used this as a method to determine if particular members were not necessary, and thereby making the stand lighter and more easily transportable. Appendix B provides figures of the FEA results on the initial design concepts. As each design concept was evaluated, we discussed the shape and placement of the members to make an assessment if the design would be feasible to build, with our given experiences. The end choice design met many of the requirements, is in the nozzle-horizontal orientation, and is described in further detail in the next section.

Final Design

Structural

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Figure 1: Stand design concept to use a sled to mount the motor to. This structure does not have self-contained tank mounting capabilities.

The design that was selected based on the fact that it fulfilled a majority of the PDS requirements, including the overall weight of the system, the

envelope size, and the transportability of the unit by two persons, and is shown in Figure 2. Due to strength-to-weight considerations and costs, a 1”x1”x0.065” steel square tubing was chosen as the structure material over other options such as aluminum, and resulted in an approximate structure weight of 120 lbs. The selection of steel also made manufacturing easier as welding is easier on steel than aluminum. A consideration that presented itself to the group during the construction of the structure is the thickness of the tubing made it prone to

burn through during welding. However, with some effort the team was able to weld the structure together with little problems after doing some practice.

The third orientation in the horizontal direction resolves both the problems of the other orientations, but has one of its own. The first major issue is that because the thrust vector is horizontal,

there is the propensity of the stand wanting to move across the ground or want to rotate due to the thrust being generated. The sliding concern is easily dealt with by designing in ground supports to absorb the force generated. Four holes are incorporated into the base of the stand for earth screws, and two legs extend out from the outer frame for additional lateral support during testing. The locating of where the motor will attach to the

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Figure 2: SolidWorks CAD model of the final design selected. Approximate weight from the model is 120lbs. The base plate is not shown, where the earth anchors pass through.

system in the horizontal orientation is the important consideration to prevent the stand from wanting to rotate during the testing. If it is mounted too low, the radiant heat from the exhaust stream would burn the surrounding ground, potentially creating a fire hazard. If the mounting is too high, the force generated by the motor will make the system want to tip over. The decision was therefore to determine the approximate location of the center of gravity of the system and locate the mounting point below this location, but as high above the ground point at practical.

The motor itself will be mounted to the stand via a ring machined to the same dimensions as what the sponsor uses on the rocket airframe. The ring is attached to the frame by being pinned to the load cells, and the load cells are screwed to the frame. Figure 3 shows the ring attached to the structure

of the test system, on top of the load cells.

The load cells that are used on the stand were designed by the team members using the bending beam-style load cell concept. Figure 4 shows a CAD model of the load cells used in the testing system. There are four of the cells used on the stand to help support the motor when installed into the ring and as well as to measure the thrust more accurately from any potential misalignment in the mounting.

The sponsor will have several spare load cells available, and the technical drawing is provided in Appendix E. As the needs increase for greater thrust output of the motors, PSAS will have the

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Figure 3: Motor mounting ring attached to the structure by the load cells.

necessary information to machine new load cells to accommodate the larger force generation. This gives them the expansion requirements for future development of motors and reduces the need to redesign the system for such an event.

Plumbing

In any bi-propellant motor in a rocket, the primary task of the plumbing system is to provide the propellants to the motor in a precisely controlled and consistent manner. Variations in fuel ratio or total mass flow rate can cause poor performance or damage the components of the system. However, while the system is on the ground, failure can lead to damage to the surrounding area and harm to the operators and those in the general

area. Furthermore, failure is more likely to occur in the developmental stages of the motor design; this makes safety the primary concern of the plumbing system installed on the test stand. Figure 5 shows the overall plumbing

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Figure 4: CAD model of the bending beam load cell with a hole drilled in the center and a slit cut to form a bridge. The load will compress the material at the slit causing strain in the side opposite of the slit, thereby creating a voltage signal in the strain

system, with various components and mechanisms and their respective locations in the system.

The system has three total fail-safe mechanisms, all of which are actuated by different mechanisms. The primary failsafe of the system is a pressure relief valve; a spring loaded mechanism which releases pressure from the propellant tank once a desired threshold of pressure has been reached. These components generally perform consistently, however can freeze in cryogenic conditions. The secondary safety component is the solenoid operated vent valve, a remotely operated valve that purges pressure from the propellant tanks. The primary function of this component is to reduce the rate of nitrogen diffusion into the liquid oxygen and isolate the pressure before the system is approached by an operator. The vent valve in conjunction with the tank pressure transducer functions as the secondary failsafe of the system. In the event that the pressure relief valve does not actuate under the desired pressure the, the vent valve is remotely

actuated to purge the system. If both the primary and secondary fail-safes do not

function, a component known as a burst disk ruptures relieving all pressure and rendering the system inoperable until the burst disks are replaced.

The secondary task of the system is to control the fuel ratio and flow rate of the system. This is performed by controlling the nitrogen pressure in each tank by pressure regulators. Nitrogen gas enters each regulator from the nitrogen supply at 3500 psi, and is reduced to a desired level between 0 and 500 psi. However the outlet pressure of the regulators does not stay consistent as the supply pressure decreases due to an inherent design flaw of pressure regulators. This is known as the supply pressure effect, which causes the inlet pressure to increase as the outlet pressure decreases. To reduce this effect, the test system uses dual stage regulators. These are effectively function as two regulators in series and reduce the supply pressure effect from 1.5% to 0.2% of the change in inlet pressure.

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Figure 5: Plumbing diagram showing how the compressed nitrogen tanks are plumbed to the LOX and the fuel, pressuring the system to send the mixture to the motor. Various valves and safety mechanisms are also included in the diagram to show how the fuel/LOX is controlled.

Once the tanks are pressurized, the system is armed and ready to release the bi-propellants into the motor. This release of the bi-propellants is performed by the ball valves operated by high powered DC electric motors. Initially, the valves are opened slightly to create a small controlled ignition within the combustion. Once combustion has become stable and consistent, the electric motors fully open the valves allowing the rocket motor to reach its full performance capability.

This system design is a pressure-fed bipropellant system in its simplest and most reliable form. By using the regulators to control the fuel mixture, the need for an additional valve to meter flow is eliminated. The system could be further improved by implementing v-port balls into the ball valves. General ball-valves with circular balls have an exponential increase in flow as the valve is opened. Using v-port balls would allow the propellant flow to be throttled linearly increasing control of the motor and fuel mixtures.

Design Evaluation

Evaluation for Structural Design and Integrity

The design of the stand to contain the fuel and oxidizer tanks as well as the system pressurizing tank was critical to the sponsor. The design of the structure puts the fuel and oxidizer above the motor which left room on the bottom for the nitrogen tank.

The sponsor wants the stand to be able to withstand a force of up to 10-kN from the motor. To successfully meet this requirement, the stand’s steel tube structure cannot exceed the yield strength of the tubing and must have a total

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deflection of less than 1 cm. A Finite Element Analysis (FEA) software was used to compute the Von-Mises stress and displacement of our stand designs, including the initial iterations of the final design. As Figure 6 shows, the stresses developed from a 10-kN point load are well under the yield strength, by a factor of approximately 3.7. The displacement of the point of loading is approximately 0.8 mm, considerably under the requirement of 1 cm.

The PDS dictates that the sponsor wants the tanks for the fuel and oxidizer, as well as the pressurizing tank, to be incorporated within the design of the

structure. This required the overall design of the stand to be somewhat taller than the sponsor had initially

thought. Explaining that having the ethanol and LOX tanks above the motor will give the best arrangement, they understood that this was necessary.

Evaluation of Function and Performance

The functionality and performance of the testing system could not be performed fully as the plumbing system was not completely defined and installed in the structure. This was due to delays in learning the requirements necessary to use the LOX and integrating it into the system. As this design is a prototype and nothing like this currently exists, many of the components had to be special made or cost between a few to several hundred per component.

The sponsor is very comfortable with the progress made in the testing system, and have expressed understanding that the design is an investment in capital and time. The goal for the team is to complete the finalizing of the plumbing components and run a water test by the end of June. This will check the complete plumbing system from the nitrogen tanks to the point where the motor will attach. The tanks that are currently installed for the

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Figure 6: FEA completed on selected design shows the stress developed with the 10-kN load is 58.9 MPa. This is under the yield stress of 220 MPa by a factor of about 3.7.

ethanol and the LOX will be filled with water. Once this is done, the nitrogen tanks will then pressurize the water in the tanks, and the plumbing system will be functional as in a real setup. This will verify that the fittings don’t leak, that the gauges and valves work as designed, and that the pressures seen at the inlet and the outlet of the pressure regulator meet the specs of the design.

Once the electronics portion of the system are completed, then the load cells will undergo some compression testing to verify that the strain gauges record the strain of the cell properly and that the data acquisition system will record and retain the data properly. These data will create the baseline calibration of the load cells, so when the motor is finally tested, the true thrust measurements will be recorded.

Evaluation for Cost and Financial Performance

The overall cost of the stand has exceeded the maximum budget requirement of $4,000, coming in at a total so far of $4,533.75. The sponsor set the budget not knowing fully how expensive the cost of the cryogenic components are and the valves used to control the flow of the fuel and oxidizer. All current cost overruns have been approved by the sponsor. The breakdown of the complete costs incurred thus far is in Appendix D, with some components still not completely defined or priced out. The sponsor will take responsibility for the remaining components, as their funding permits.

Evaluation for Assembly and Transport

The final design of the stand incorporates all of the major systems to be within the steel frame, and therefore requires very little assembly, per the set-up time requirement. Once the stand is deployed, the user inserts and

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sets the four earth anchors and extends the legs for additional support. The tanks are set into position and hooked into the plumbing system, and the electrical connections made for recording the measurements.

The outside envelope of the stand measures 6.5 feet tall, 3 feet wide, and 2 feet deep excluding the wheels, and fits within a standard long-bed pickup truck, which meets the requirements dictated in the PDS. The wheel casters on the stand facilitate the loading and unloading of the stand, as well as making it easily transportable from the pickup to the testing site by two persons. The most difficult portion of transporting the test system is loading it into the pickup truck. It will require some heavy lifting to get the front end up onto the truck bed.

The evaluation for the transporting of the tanks needs to still be determined. The aspects of transporting LOX in the limited volumes required hasn’t been answered by personnel within the cryogenic fluids field, and the Department of Transportation does not have any readily available documentation at the time of this report. This is a critical item that will need to be resolved before the test system is deployable as designed. Some thought was given to determining if gaseous oxygen was going to be easier for purchasing and transportation, but the decision matrix provided in Appendix C shows that the benefits lie with the choice of using LOX.

Once the stand it completed and tested, a User’s Manual and Standard Operating Procedures will be written up for the sponsor and the future users of the system.

Evaluation for Manufacturing and Maintenance

The manufacturing of the stand was much more difficult than anyone had anticipated. The addition of the legs at the mounting point to the rear of the stand is the main contributing factor to the difficulty of the build. The

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angles were not easily determinable, and required several dry fits and reworking to get them to the correct position. Also, with the welding, the stand became very rigid, and while generally a positive aspect, it became somewhat of an issue when attempting to get even the most slightly misaligned components to mate up properly. The welded design was chosen over a bolted design though as the bolted frame would be considerably more expensive due to the hardware required and the thicker material needed would add weight to the system.

The welding was a learning experience for the team as well. We got some help from several other more experienced welders, but the weld beads still required significant grinding and working to shape them into the stand better. Several hours were dedicated to this process. However, with the experience gained from this, future works and repairs will not require as much finishing work as the initial weld will be smoother and less bulky.

Recommendations

During the construction of the test system, several opportunities presented themselves to help make the device more useful and friendly. We suggest that the stand be powder coated to help protect the metal structure from the elements and also to give the stand an aesthetically pleasing look. This will also provide some protection while the device is in storage by not letting moisture in the air contact the steel surfaces. A small storage box for the earth anchors and spare load cells would also be a good suggestion so they are readily available and easily located.

When conducting testing on the motor, a close-up view of the running motor jet stream may be desirable for the sponsor. One solution is to incorporate a boom or vertical member to which a webcam can be mounted to stream

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back live video feed of the motor’s performance. This also makes recording the visual data possible for future replay.

Due to the significant costs associated with cryogenically-rated valves, the valve currently used on the stand is much larger in diameter that it need be. A replacement valve with the appropriate line diameter would be a better fit and will reduce the need for reducers in the lines. This is more for aesthetics and similitude of fitting sizes.

Conclusion

While the test stand is not fully completed, we are pleased with the progress of the project. The hurdles overcome in learning how to fuel a bipropellant rocket motor have been a valuable learning experience for both the team and the sponsor. The sponsor is ecstatic to have a testing system for the development of their rocket motor, and we feel great that we had the opportunity on this unique project and were able to deliver to them a product they are happy with.

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Appendix A

Table A1 – PDS for the Rocket Motor Testing System

Priority Customer Target Target Basis Verification

••• PSAS 10-10,000 Customer Defined Testing

••• PSAS 0-6.894 Customer Defined Testing

••• PSAS -200 - +540 Customer Defined Testing

••• PSAS ±1.5% Customer Defined Testing

••• PSAS 2 Group Decision Analysis

••• PSAS 0-50 Group Decision Analysis

•• PSAS Sealed Group Decision Testing

•• PSAS < 300°C / 3min Group Decision Analysis & Testing

•• PSAS >10 Customer Defined Analysis

••• PSAS 2 Customer Defined Analysis

••• PSAS <254 Customer Defined Analysis

••• PSAS <180 Customer Defined Analysis

•• PSAS 1,112-1,334 Customer Defined Analysis

••• PSAS N/A Customer Defined Testing

• PSAS <3 Customer Defined Research

• PSAS 1 Customer Defined Testing

•• PSAS No Customer Defined Testing

••• PSAS <1 hr Customer Defined Testing

•• PSAS 2 Customer Defined Testing

• PSAS 2 Customer Defined Testing

••• PSAS >20.684 Customer Defined Testing

••• PSAS <1 Customer Defined Testing

••• PSAS 0 Customer Defined Testing

••• PSAS N/A Customer Defined Testing

••• PSAS N/A Customer Defined Testing

••• PSAS 99% Customer Defined Testing

•• PSAS 305 Customer Defined Testing

•• PSAS 70dB - 305m Customer Defined Testing

••• PSAS 38°C - 1/3m Customer Defined Testing

••• - High Priority, •• - Medium Priority, • - Low Priority

Requirement Metric

Performance

Measure Thrust Curve N

MpaMeasure Thrust Chamber Pressure

Measure Temperature In Various Locations °C

Measure Strain In Test Structure m/m

Environment

Weight

N

Life In Service

Size and Shape

Heat Shield

Statically Stable Under Load Movement (cm)

Remote Operable Reliability %

Flashing Red Light Visibility (m)

Intensity at Distance

Temperature at Distance

Emergency Kill Switch

Dust

Dry Grass

Portability

Width

Maximum Weight

N/A

Shut Off Valves

Air Raid Siren

# Of People Required To Move

cmLength

cm

Resist Forces Due To Thrust FOS

Temperature °C

No Accumulation

Temperature/Time

Years

N/A

Fuel & Oxidizer Flow (cm 3̂/s)

Purge Lines

Installation

Setup

Necessary People

# Of People Required

MPa

Time

# Of People Required

Ergonomics

Operation

Safety

Explosion Resistance

Maintenance

Interchangeable Test Devices N/A

Availability Of Parts Weeks

# Of People RequiredServiceability

Tools Required Specialty Yes/No

I

Appendix A – cont.

Table A1 – PDS for the Rocket Motor Testing System – continued.

••• PSAS 10-10,000 Customer Defined Testing

••• PSAS 0-6.895 Customer Defined Testing

••• PSAS 0-538 Customer Defined Testing

••• PSAS ±1.5% Customer Defined Testing

••• PSAS Yes Group Decision Analysis

••• PSAS Yes Group Decision Manufacturing

••• PSAS Yes Customer Defined Analysis

••• PSAS Yes Customer Defined Analysis

••• PSAS >3038 / 3 Customer Defined Testing

••• PSAS 100 Customer Defined Analysis

••• OSHA Yes OSHA Defined Requirement

••• PSAS Yes Group Defined Requirement

••• PSAS Yes Group Defined Requirement

••• PSAS Yes Group Defined Requirement

••• PSAS Yes Group Defined Requirement

Lightweight

Simple To Manufacture

Corrosion Resistant Yes/No

Cryogenic Plumbing Yes/No

Heat Resistant °C / min

Operation Manual

LOX Handling Manual

Yes/No

Yes/No

CAD Drawings Yes/No

Documentation

Bill Of Materials Yes/No

Material

Yes/No

Yes/No

MPa

°C

Testing

Load Cell Newton

Pressure Transducer

Thermocouple

Strain Gauge m/m

Yes/No

Quality and Reliability

Reliability Percent Of Time

Applicable Standards

Transport Of Compressed Gas

II

Appendix BThe following figures are our initial design considerations and the resulting FEA for the stress developed and displacement of the frame. All of the designs met the stress and displacement requirements, but the design of the frame was either very complicated or did not incorporate the tanks within the structure.

III

Figure B1: Design Concept 1. This was determined to be too complex to manufacture, and does not accommodate for the tanks within the

Figure B3: Design Concept 1. The stresses developed are 72.8 MPa, well under the yield limit of the material.

Figure B2: Design Concept 1. The displacement is 0.1mm, well under the 1 cm requirement.

Appendix B – cont.

IV

Figure B4: Design Concept 2. This is a sled design frame. While easy to manufacture compared to design concept 1, the tanks are still not integral to the

Appendix B – cont.

V

Figure B5: Design Concept 2. The stresses developed are 30.2 MPa, significantly under the yield limit of the material.

Figure B3: Design Concept 2. The displacement is 0.61 mm, again below the limit of 1 cm.

Appendix C

Table C1 – Design choice matrix for choosing the oxidizer for the motor.

Factor (1-2): 0= No Priority, 2= High PriorityWeight (1-4): 1= Worst, 4= Best

Installation 0.5

Safety 2

Reliability 0.5

2Cost

Transportation 1.75

Total 10

2 3

2 1.5

22.5

3

15.5 21.5

2 3

2

Size 1 1 4

1.25 2 2Maintenance

1 4

Oxidizer Decision Matrix

PDS Category Factor High Pressure GOX Low Pressure LOX

Weight 1

While there are some difficulties in dealing with LOX, such as making sure the liquid does not come in contact with organic material on the ground, the pressures required to utilize GOX are far more difficult to handle.

V

Appendix DTable D1: Bill of Materials and Costing for the test system. The highlighted components still need to be sourced and purchased.

Part Price Quote Quantity needed Total Quantity

PurchasedTotal

PurchasedManufactuer or

Distributor X = Purchased

Wheels $14.99 2 $29.98 2 $29.98 Harbor Freight X Total NeededTotal

PurchasedCaster Wheel $17.99 2 $35.98 2 $35.98 Harbor Freight X $4,598.60 $4,533.75Ground Screw $13.97 4 $55.88 4 $55.88 Home Depot X

Frame Material $85.00 1 $85.00 1 $85.00 Eastside Steel X

Frame Material 2 $17.00 1 $17.00 1 $17.00 Eastside Steel X

Plate and Leg Material $105.00 1 $105.00 1 $105.00 Eastside Steel X

Nitrogen Tank $0.00 1 $0.00 1 $0.00 Luxfer X

7/8" to 1/2" compression fitting $20.80 2 $41.60 2 $41.60 Swagelok X

1/2" to 1/4" tube adapter $11.18 2 $22.36 2 $22.36 Swagelok X

1/4" Branch Tee $28.88 1 $28.88 1 $28.88 Swagelok X

Needle Valve $60.98 1 $60.98 1 $60.98 Dixon X

Tank Hose $32.70 1 $32.70 1 $32.70 Associated Hose X

Pipe Nitrogen $2.57 12 $30.84 12 $30.84 Swagelok X

Ferrule Fittings $7.35 8 $58.80 5 $36.75 Swagelok X

Ferrule Tee $23.40 2 $46.80 2 $46.80 Swagelok XHex Nipple $6.32 4 $25.28 4 $25.28 Swagelok X

Ferrule Elbows $14.08 2 $28.16 2 $28.16 Swagelok X

1/4" Female Tube Adapter $10.15 4 $40.60 4 $40.60 Swagelok X

1/2" Female Tube Adapter $13.77 2 $27.54 2 $27.54 Swagelok X

1/4" Male Tube Adapter $6.32 7 $44.24 7 $44.24 Swagelok X

Ferrule Cross $42.54 1 $42.54 1 $42.54 Swagelok X

Pressure Transducer (3000 psi) $188.75 1 $188.75 1 $188.75 Ashcroft X

Ethanol Regulator $523.86 1 $523.86 1 $523.86 Swagelok X

Oxygen Regulator $523.86 1 $523.86 1 $523.86 Swagelok X

Check Valves $48.55 2 $97.10 2 $97.10 Swaglok XSolenoids (Nitrogen) $98.10 2 $196.20 2 $196.20 Asco X

Manifold material $62.00 1 $62.00 1 $62.00 Brass & Copper X

Relief Valves $151.49 2 $302.98 2 $302.98 Swagelok X

Bleed Valve $50.82 1 $50.82 1 $50.82 Swagelok X

Vent Valves $123.57 2 $247.14 2 $247.14 Asco X

Pressure Transducers (600 psi) $188.75 2 $377.50 2 $377.50 Ashcroft X

Pressure Gauge (600 psi) $19.44 2 $38.88 2 $38.88 Winters X

Slik-Tite $2.56 1 $2.56 1 $2.56 La-Co X

LOX Dewar $600.00 0 $0.00 0 $0.00 ---

LOX withdrawal device $598.00 0 $0.00 0 $0.00 Technifab ---1/2" Male Adapter $13.77 0 $0.00 0 $0.00 Swagelok X

Tee $46.48 1 $46.48 1 $46.48 Swagelok X

Filters (LOX) 1 $0.00

LOX Tank $372.94 1 $372.94 1 $372.94 Hoke X

1/2" Ferrule Fittings $16.98 5 $84.90 5 $84.90 Swagelok X

3/4" Ferrule Fittings $21.84 2 $43.68 2 $43.68 Swagelok X

Cryogenic Ball Valve $150.28 1 $150.28 1 $150.28 Flowserve X

Valve Pipe Adapter $15.42 2 $30.84 2 $30.84 Merit Brass X

Bleed Valve $50.82 1 $50.82 1 $50.82 Swagelok X

Pipe (LOX) $0.00 1 $0.00 0 $0.00 Swagelok XBurst Disks (1000 psi) 2 0 $0.00 ---

Burst Disk Holder 1 ---

Pipe (Ethanol) $0.00 1 $0.00 0 $0.00 Swagelok X

CGA 320 Nipple $5.03 1 $5.03 1 $5.03 Radnor X

CGA 320 Hex Nut $3.67 1 $3.67 1 $3.67 Radnor X

Ethanol Tank $132.99 1 $132.99 1 $132.99 Luxfer X

Aluminum Nipple $9.99 1 9.99 1 $9.99 Russell X

1/2" Female Adapter $20.29 1 $20.29 1 $20.29 Swagelok X

Tee $46.48 1 $46.48 1 $46.48 Swagelok X

Manually Operated Ball Valve $42.80 3 $128.40 2 $85.60 Sharpe Valves X

Filters (Ethanol) 1 ---Burst Disks (1000 psi) 2 ---

Burst Disk Holder 1 ---

Frame

Plumbing (Nitrogen)

Plumbing (LOX)

Ethanol

VI

Appendix E

Figure E1: CAD drawing for the load cell used on the testing stand.

VII