Quote:
|
Originally Posted by wjwj
You were right! That's why I asked. Thanks for the suggestion.
I was actually going to use either E6's or F10's originally. However, I want to do many launches, and each motor costs over $20 USD. That's as much as it costs me to fill up my car!  |
You can do whatever you want. So do it. Ignore the nay sayer. (I do, as do others around here)
Go with James (Recrystallized Rocketry) semi-positive experience with endburning and build on it.
Make some motors and do the tests, make more motors do more tests and if your results match or exceed those of James' tests, go fly.
Keep in mind that the E6 has an initial kick of ~12N (Red trace), which I suspect is done with a short core before transitioning to end burning.
An example of this short core is shown at the nozzle end in the second pic of a BlackPowder motor (eg, Estes, Quest).
The length of the core will affect the initial thrust and also the length of burn.
You will need to test this, along with nozzle diameter, to tweak your thrust curve.
You may also want to have a look at simulation programs like BurnSim. Will save you lots of time.
I've never actually tried to sim an endburner in BurnSim, but I'm sure there is a way to sim a short core transitioning to end burn. You might have to cheat, with a short Bates grain and a solid grain. Have a play
You've got me intrigued now, I'm going to fire up BurnSim
Edit: If you want the vital statistix for KNSU in Burnsim(they're not included) send me a PM.
More Edit: More reading:
http://www.thefintels.com/aer/exper...ropellants2.htm
MORE edit... BurnSim has a Cored End-Burner option, make life simpler
