Trying to get the silver vehicle and the new motor ready to test. Its at that very frustrating 90% point. It looks like its done, and all you have to do is assemble everything. In the past I would say we will test on Saturday the 18th then scratch that the 25th scratch that the 2nd. etc… after 4 weeks of this everyone thinks I a flake. I know better now it will be ready to test when its ready to test. (My son still has a fantasy that it will be ready on the 18th)
9 comments:
Paul,
Are you going to use the assembled silver ball for the test stand of the new motor, or it's a matter of putting together a good test stand for some static tests out at FAR?
With the good vertical test stand at FAR the vehicle can be easlily mounted and thus makes a good test stand. This way you are debugging the vehicle at the same time. One development, not two.
Good news - Its starting to get very interesting. I wish you the best for the test firing of the new engine and shake down of the vehicle.
You have not shown the new engine in its completed form - that is with the catalyst pack and peroxide injector section welded on top. It would be a fairly long section?
Any way, good luck and I wish you well on the tests.
Paul,
David - look at his construction photos, particularly http://www.rasdoc.com/blog/ChamberMach10.jpg
The peroxide is being injected via holes in the side of the chamber at the top of the cooling channels, above the cat pack. Paul has mentioned that even with that he will be having a diffuser plate before it hits the cat pack.
As for the cat pack, AFAIK, Paul is keeping that close to his chest for NDA reasons.
Paul - I know you are keeping the catalyst info under wraps due to NDA, but I am curious about how you are doing the injector of the fuel below the catpack. Any hints you could give there? I've been digging around trying to see what people used for the fuel injector in H202 biprops and didn't find a lot of info. Armadillo kinda bailed out of that right when they where starting to investigate various options.
Also, are you planning for an aluminum motor on your electronically pumped version? I really like the idea of using an electric pump with as much off the shelf parts as possible, and having a motor you can make yourself on a CNC lathe/mill setup. Very OTRAG.
Whamodyne - thank you for the comments. I do understand both the points you raised and the NDA restricts what can be discussed. I was mainly interested in:
1) Is the side injection of the peroxide enough or does it need an extra plate for which it redirects the flow for even distribution over the catpack.
2) I was interested in how the Kerosene was going to be injected. I assume the injector plate would have a series of tubes (or even singular central tube) and maybe a spray bar at the end that goes through the catpack.
I have always assumed the silver ball is using the electric pump so the fuel tanks can be full which is necessary for the full flight profile.
Any way, exciting to see the tests. Best wishes.
Carrying on from the previous comment. The kerosene could be directed through the cooling jacket and there for the side injection would be fine and nothing further needed. That also leaves the catpack and peroxide injection on top be applied in the standard arrangement that is currently working so well in the blue ball.
I need to go back over the previous posts for the engine design. This to be would be more logical to me. Downside would be that the engine would be unable to be tested without operating in Bi-prop mode for long.
This is so great getting the old brain thinking about this and that and then researching further - I do thank you Paul. This is fun. Time to do further reading.
This motor does not use the NDA cat. It uses the metal monolith that Armadillo was nice enough to send me. It that does not work I will build another NDA cat to go in it. Injection scheme is that the fuel is injected just below the cat pack via small stainless tubes welded to the bottom spider/spreader. This is fed via a tube up the center. The area where peroxide and fuel run together is solid stainless with no welds or fittings.
Lastly this vehicle is not pumped just pressure fed, we had to triage the pump project for now as we can only do so many things at once.
We spent the weekend at FAR working on our peroxide sparging system. The containers is now wired and plumbed, the hot water heater works and we are only waiting on some components of the dry air system to give it a try. Those parts should be here this week.
paul - thanks for the feedback. If possible, I would love to see pictures of your fuel injector when you get it running, can't quite visualize what you said. Might be due to too much (or too little!) coffee at the moment.
Glad to hear your sparger is coming along. I think it's possible there is a small market for 85 to 90% h202 available out there, more people might start playing with it if there is a steady source in the FAR/Mojave area.
I was doing a mental exercise on the pump engine, trying to figure if an aluminum regen engine at those chamber pressures (700-900 psi) could be done with a garage based CNC machine. I'm guessing yes, with a fair amount of trial and error.
Good luck and know that a fair number of us are following along for the ride and are rooting for you.
Thanks Paul. I agree totally with Whamodyne. So with the stainless insert you could also apply some film cooling as well. With the external pressure tanks we have a flying Mickey Mouse looking construction - get the Disney sign up.
With at least a few other teams doing hops or getting closer to flying now - it will be an interesting year. Fingers crossed that it goes (relatively) smoothly for you Paul.
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