| This is my second
attempt with this fuel in a 38mm motor. Test #1 was at a KN of 147. It
resulted in a 40 second burn time. It was incredible to watch. It also
answered the question how low is too low of a KN for this fuel.
Attempt #2 was at a KN
of 313. This is in the range that this fuel likes. I also tried
out a new ignition method on this motor. I cast a 3/8" slug of 65% KNO3
- 35% Dextrose - 1% RIO fuel at the top of the forward grain. The motor
lit within .6 seconds. That is 4 - 6 times faster than before. I will
try this trick again with the next static test.
I was also able to
collect some useful data from the firing. The numbers look too
good to believe, so for now I choose not to believe them until I can
test again. I will post them to make it easier to compare later.
131.5 gram of fuel fired
in .75 seconds. 184.05 Newtons of total thrust. 230.06 Newtons of
average thrust. Anyone familiar with sugar motors is saying " no way
you got that thrust from 131.5 grams of fuel." I am saying the same
thing. My test stand was calibrated before firing and that is what the
numbers worked out to. Only another test will tell. I expected a better
than normal ISP, but not this good.
38mm x 112mm static test 2-14-07
Overall it was a fun
day. This is the reason I love Experimental Rocketry.
|
