Saturday, November 18, 2006, 04:35 PM
Today the propulsion team wrapped up a few remaining plumbing items like repositioning the purge solenoid, bending the steel tubing for the ignitor and combustion chamber pressure sensor, and making room on the tank stand for a fuel tank relief valve:
Later in the work day, Nichole and Amanda walked the students though the process of making composite test panels. Over the next few meetings, the team will be making many different test samples using various fibrous materials and resins in order to find the best combination of fiber and resin to resist heat in the combustion chamber of the rocket motor. After these test panels are cured, we will test the samples by burning the top side of the test sample with a torch while measuring the temperature of the bottom side of test sample using a high temperature thermocouple. This series of tests will show which type of fiber/resin combination is most resistant to heat and will therefore do the best job of protecting the walls of the rocket combustion chamber when the rocket motor is operating.
Here is a picture of a student applying resin to test sample #3:
The test samples were wetted with a predetermined quantity of resin, applied to plexiglas backing material, and then vacuum sealed in a food-grade vacuum sealing machine to increase the density of the finished product:
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Saturday, November 11, 2006, 08:13 AM
Last Saturday we continued our work on the ignitor plumbing, the main plumbing lines, and the failure mode analysis. The rocket motor is nearing completion and it certainly is exciting! At this point, the fuel plumbing is essentially complete – we just need to make the final flare in the main line, the install the purge system line, and add a few nit items. In the following picture, Carl is installing the N2O expansion chamber (a component in the ignition system):
In the next picture, you can see the fuel system and ignitor pluming downstream of the main fuel valve. In the middle of the picture you can also see the motor ignitor on its temporary wooden mount. The liquid oxygen plumbing will lay to the left of the fuel system plumbing:
In addition to hardware work on Saturday, part of the team studied the expected motor operation and brainstormed potential failure modes. With these failure modes in mind, this group designed automatic computer control sequences to "safe" the system if one of these failures occur. These logic sequences were handed off to the computer team to be installed into the rocket motor control system:
Our next work day will be on Saturday the 18th. On that day we will install the liquid oxygen valves and complete the motor plumbing.
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Saturday, November 4, 2006, 05:15 PM
This week, the propulsion team focused our efforts on two major areas: the injector/ignitor and the procedures we will use to safely test fire the rocket motor. The hardware team spent most of the day working on the plumbing immediately upstream of the injector. This area consists of the diversion plumbing that divides the 3/4 inch tube of alcohol into two 1/2 inch tubes which are then plumbed directly into the injector. Ed and Julien worked on measuring and tapping two 3/8 inch NPT holes into the injector in just the right spot to feed the outer fuel manifold of the injector (it was a very tight fit). Here is a picture of Julien measuring the outer fuel manifold of the injector:
Also immediately upstream of the injector is the motor ignition system. Nathan welded the major pieces of the ignitor together on Friday, allowing Carl and Jewel to install the N2O and butane plumbing lines which feed the ignitor. These lines must fit in a very small area of the test stand, must move freely with the motor itself, but must still be accessible to the test firing team - making the installation complicated. The team made good progress on this system, and should be complete next weekend.
Lastly, the team finished the assembly of the low pressure helium system, with the exception of three valves, which should arrive this week:
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