Aerospike

[edwardw]

Finally! I have my aerospike nozzle machined and nearly completed. The only things left to do are drill and tap 9 different holes for retention. The project turned out about as hard as I expected. Took me about 2 hours to get her done, but here she is! I'm hoping to do some low pressure (<500 PSI) in two weeks.

Edward

 

[edwardw]

Here is the base of the spike.

 

[edwardw]

Here is the retaining ring.

 

[rocketsonly]

Nice job! What kind of machinery did that require?!

 

[aksarben10]

Very nice, wish I had a lathe. Can you post some pictures of the lathe as well, so I can dream.

Are you going to run sugar propellents in it?

Scott

 

[edwardw]

I'm going to run it on the standard KNCP at some low Kn's so the pressure is less than 500 PSI. The finish throat turns out to be the equivalent of a 1/2 to 5/8 diameter throat, depending on how I adjust it. Tonight I'm taking the case and nozzle and putting a little dry ice in the case. Then I'm going to watch the flow from the annular port. I haven't decided on a truncation point yet, but when I do I'll get that machined and done I'll add a small port so that it is a little more efficent in theory. It's a 54mm spike, so I'm going to throw it in a 12" casing and make a small J out of it.


Edward

 

[GL-P]

Sorry, I have no experience with motors but what is the difference between an aerospike nozzel and one you'd find on a regular motor. Is it a performance advantage?

Thanks

 

[aksarben10]

This site explains it alot better then I can, but basicly its an altitude-compensating nozzle as the atmospheric pressure changes so does the shape of the nozzle.

https://en.wikipedia.org/wiki/Aerospike


Scott

 

[GL-P]

This site explains it alot better then I can, but basicly its an altitude-compensating nozzle as the atmospheric pressure changes so does the shape of the nozzle.

I get it! I just read it and now I understand the concept! Cool!

 

[edwardw]

Here is another pictures. I got the retainer retention put in today. Each socket head screw has an o-ring below it just to make sure no gasses are leaking. Now I just have to make the retention holes on the sides to the casing.

Edward

 

[edwardw]

Here she is, installed on a 15" 60.5mm case. Now I just need to cast the loads and test away!

Edward

 

[Loki]

Why is it way up inside the case like that? Won't the case act like a traditional nozzle bell and kill the aerospike effect?

 

[edwardw]

I have to cut the case down to within and 1/8 of the spike. I just messed on some measurements, didn't realize the ruler didn't start at the edge and actually started 1/2" in. Oops.

Also, this one I'm not too worried about performance, I want to see if my idea for feeding the annular port will work like I think it will. Once I get some firings, I've got another design (very similar) that I'm going to machine.

Edward