08-15-2009, 01:48 PM
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BARCLONE Rocketry
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Join Date: Mar 2005
Location: Mobile, Alabama
Posts: 5,357
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Quote:
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Originally Posted by blindeye bob
The Master Confesses. What do we left to beleive in?
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Shucks, if you thought that was confession... 
As it turns out, I think I may have tried to do this one in RockSim several years and two versions ago. This design will not simulate. There is still a problem within RS9 when you try to simulate those engine cheek cowls, if they interfere with the engine tube (which happens in this design). RockSim has no way to "ignore" the material of those cowl tubes which intersect with the inside area. When the design is loaded up, the engine finds itself with those tubes running through it, and you get NAN.
Having said that, I think I can still get a reasonable projection of what the design might do. As-is, the design is slightly unstable. This is due to the forward position of those main wings. The design needs 1/2 oz of ballast just behind the nose cone shoulder to get the margin up to 1.41 on a C6-5.
Some adjustments made in the simulation: - The lower sub-fins were enlarged by 20%.
- The rear section of the intake spike (BT-5T) was eliminated.
- The intake cones were changed to BNC-5AX (2.25"), and the shoulders were removed.
- Both spikes can be obtained from one cone.
- The intake tubes were lengthened to 7.75", to account for the additional length of the curved intake pieces.
With the additional ballast, the model should be stable, and should fly reasonably well on B and C power. Until we get some way of forcing RS to ignore the inside material from the intakes, this will continue to give us a NAN simulation.
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