Sunday, March 18, 2007

Good Test Results...


The testing went well on Saturday.
We fired 1/4 of a vehicle. We had some software sequence problems that caused it to start roughly but we ran it for 16 seconds with no burn through or other damage.
The Video is here: Video

Sunday we disassembled the motor and analyzed the data. There is good news/bad news.
Good news, the regen motor shows no signs of melting. The bad news is we looked at the data and the presurization problem was more severe than we thought. We never got up to operating pressure. The operating pressure is supposed to be 80 to 250PSI we ran it from 40 to 120 during the test. So we did not run it anywhere near full throttle. This is actually useful data as it shows the engine is stable at low feed pressures, all the way down to 50 PSI. We got no load cell data.











We also fired the 650 Lb Ablative we tried to fire a few weeks ago.
That video is here

4 Comments:

Blogger kert said...

hey, the real hot flamey stuff ! nice progress

12:59 PM  
Blogger Carl Tedesco said...

Paul,

You said that you may have opened your propellant valves before you had completely pressurized the propellant tanks. If you're using software to sequence these events make sure you verify the tank pressure is correct before you proceed to opening the valves. If you still don't get correct Pc, look closely at your regulators and make sure they have ample Cv. What regs are you using?

--- Carl

7:31 AM  
Blogger Paul Breed said...

The sequencing was supposed to be manual for this test. Alas I had
missing "break"; in my command parser and it proceded from Presurize to Run with no time interval in between.

I've also determined that the step in the chamber pressure graph was from the fuel orifice plate around the pintile shifting. I'm making a new one of slightly different construction.

7:37 AM  
Blogger Carl Tedesco said...

How did you determine it shifted?

1:03 PM  

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