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- Great progress for revamping fall onboarding, more work still needed to change slides and finalize the plans.
- Igniter redesign in progress, need to do some more research and work on both the mount and switchbox before doing a second test early fall.
8/15/2023 Tue
- Kevin machined the Helios test stand hot fire!
- John made CAD for various igniter positions to light Helios
Test stand:
Helios igniter designs:
Is functionally the same but covers the nozzle entirely so in theory would get ejected as soon as the propellants are throttled (and hopefully ignited). It's good to note that for the Estes C6, it's 18mm so can fit entirely through the ~20mm throat.
I think this design could be dangerous because it could fail to ignite until the propellants build up past the throat and lead to a hard start (or just fail to ignite altogether). We ran at the end of last semester to assess soot buildup in the injector holes using this configuration.
It involves machining a simple aluminum housing for the motor, and machining/tapping a hole in the side of the chamber to screw it in. I'm not sure if this would improve the soot buildup problem, but it clears the nozzle and removes the worry of the lit motor flying off. The main problem here is machining/tapping the hole in the side of the chamber might be difficult?
There was also thought of placing the igniter in the faceplate, but I don't think this is feasible for us since it requires we drill through and seal like 3 components, and comes super close to the injector holes (risk of drilling into one of the injector holes and blocking it/messing up the flow). Although, this probably would be ideal for the soot problem.
This final design is chamber-mounted, and angled away from the injector so might help alleviate the soot issue (but would require testing). The idea is to angle the motor below the point of impingement so as to combust the propellants once they vaporize. The problem here is it's probably super difficult to machine the igniter hole at an angle on the chamber.
8/20/2023 Sun
- Waiting on legal agreements where we want to test
- Onboarding material in progress
- Igniter redesign is in progress
8/23/2023 Wed
- Garett finished machined the Romulus engine!
8/27/2023 Sun
- Alex did inital calculations for making the Romulus testing manifold for a water test without the nozzle
- John finished first onboarding lesson
The idea is to have a manifold with an inlet port that routes the fuel/water to the anulus without having the nozzle so we can see the impingement of the fluids. To accomplish this we can have a volume with a decreasing area as a function of the angle around the circle. This is needed to preserve the fluid velocity so the fluid around circle is uniformly ejected. As mass flow decreases, so does the velocity; we compensate for this by decreasing the cross sectional area. It will not be a linear function, but we might be able to approximate with a linear cut for machining purposes.