| B6 Engine |
| The Design Specs: - Thrust: 1100lb average - Burn time: 6.33 seconds -Propellant mass: 24.7lb -Total Impulse: 6347 lb*s - Engine mass loaded: 55lb - Engine diameter: 6 inch - Engine length: 33 inch |
| The Design: |
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| The nozzle on this engine will have a graphite insert, dark gray, glued in at the throat area. This is because the temperatures in the throat region will reach around 3000F. The graphite can handle these temperatures without melting or eroding. The graphite insert will thread into the steel nozzle. The graphite and the steel will both be machined at the same time to get a smooth transition. The propellant, red, is a rod and cylinder design. This gives an almost flat thrust vs. time curve with the maximum thrust produced at lift-off. The rod portion of the propellant is cast onto a 3/8" diameter rod which is attached to the bulkhead, the right side of the engine. Both sections of propellant have equal burn times. Both the nozzle and the bulkhead are each held in by 12 3/8" machine screws. The combustion chamber is made out of .25" thick T6-6061 aluminum tube. |
| Analysis: |
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| The following pictures show the analysis of the bulkhead and the stresses generated by the chamber pressure and the propellant grain pulling down due to the rockets calculated acceleration. The maximum stress is 26,000 at the concentrations caused by the sharp edge on the inside. The maximum stress in the rest of the part is 17,000psi. The allowable stress for the aluminum at 400F is 30,000psi. Ignoring the pinpoint stress concentration the safety factor is 1.75. | |
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The temperature analysis of the nozzle shows that the graphite insert will reach 2900F while the steel section will stay under 2000F. Since the steel melts around 2400F the graphite is used to handle the higher temperatures. |
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Thermal analysis of the combustion chamber and the insulation protecting it. This analyasis assumes the worst case scenario of maximum heat transfer on the insulation through the entire burn. In the actual burning the propellant acts as a very good insulation through most of the burn. |
| The Finished Engine |
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The set-up that was used for the drilling, tapping, and countersinking all the bolt holes. The pictures show the nozzle being drilled but all three parts were done in this manner. The nozzle was done on the CNC lathe, the bulkhead was done on the manual mill, and the interior of the combustion chamber was done on the mill with a boring set up. |
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Here are pictures of the finished engine assembled. There hasn't been a propellant grain made yet. The casting set-up to make the rod and cylinder grains is done. The engine stands 33" tall with the nozzle sticking out another 1"-2". The space between the nozzle screws and the end of the combustion chamber are for fin attachment. The fuel grain will be 25.25" long. |
| Testing: |
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The B6 engine was tested on 4-8-06. We collected good thrust data and saw the same lower impulse and longer burn time as seen with all the S3 engine tests. Collected Data:
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The S3 system is designed as a test vehicle for electronics, launch procedures, and recovery methods. The first version was sucessfully launched, decended under parachute, but was then never found. The second version is being designed, build, and flown late spring of 2006. |
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The B6 system is a 6" airframe and engine designed to test supersonic flight and high altitude recovery. The airframe was designed and build by a senior design group that graduaded spring 2006. The engine was static fired spring '06 and awaits modifications before launch. |
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The liquid system will power a sounding rocket carrying 10kg of payload to 100km. |
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Various electrical systems are developed in this project to cover a wide variety of tasks. The STM (static test module) is used to collect the data from static test fires. A data collection package has been developed and flown on several flights by CALVEIN. The flight parameters of our own rockets are measured and the recovery system is triggered by custom designed units. |
The powered dart project involves a collaboration with Lunar Rockets and Rovars of California. The goal is to take the existing Super Loki dart system and integrate an engine into the current unpowered 2nd stage. The powered second stage will increase the altitude and be the first powered dart launched using the Loki system. |
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This section shows everything else that the group has done. The above pictures are from a static fire of a shuttle booster, the SRB, done north of Salt Lake City by ATK Thiokol. |
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