The square pointy bit broke the air up before it hit the square flat bit?Interesting results. I would like someone to attempt an explanation as to why the crazy shape of #10 did best, while elliptical fins (#1) did worst by a wide margin. Not what I would have guessed, that's for sure!
Hey, don't get all technical with me.The square pointy bit broke the air up before it hit the square flat bit?
Do you really think round fins would actually *invert* the standings?I believe if they were all rounded ( OP points out the difficulty with identical rounding ) your instincts would have been pretty close.
For #10 that really is my best guess.Hey, don't get all technical with me.
Do you really think round fins would actually *invert* the standings?
I really am curious to understand these results. Short of a wind tunnel test I suspect we'll be left to speculate.
Ah, I was wondering about that too. Cool experiment for sure.all the fins had an area of 4.09 square inches
I would have picked "anything other than #10".I would have picked #9.
I did not do that .. just built then flew
The rocket weighed 4pounds 3oz...
Hey, don't get all technical with me.
Do you really think round fins would actually *invert* the standings?
I really am curious to understand these results. Short of a wind tunnel test I suspect we'll be left to speculate.
I'm spitballing here but lets say that motor performance can vary +5% (There is an official figure but I'm not sure what it is off hand).
Some research on the ThrustCurve's site shows that NFPA 1125, Code for the Manufacture of Model Rocket and High Power Rocket Motors, allows an alarming amount of motor deviation from stated values....
That's why running all these through a simulator would be great.
- The total impulse must not have a standard deviation greater than 6.7%.
- The ejection delay must not vary more than 1.5 second or 20% (whichever is greater, up to 3s) from average.
- The average thrust must not vary more than 20% (or 1N for model rocket motors, 10N for high-power motors, whichever is greater) from average.
Add the impulse deviation and the average thrust deviation and we end up with results that vary so wildly that it's hard to gather any useful data from a test unless some sort of on-board electronics are used to evaluate that actual motor performance during the test.
Hey, I told you I liked 10!Cool!
With ten different flavors, how many flights are you doing on each to get statistically relevant data?
I really like #10!
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