Friday, October 27, 2006

Simulating the Bullet

While looking at accelerometer options, the question came up on how much acceleration the hardware needs to handle. For example, this DE-ACCM3D is a mighty tidy product but the measurement range is +/- 3G. RockSim to the rescue.

RockSim wireframe representation of my extended LOC/Precision Bullet

It was a little painful to build the extensions to the Bullet in detail, but it's in there now so I just give RockSim the launch conditions and tell it what motor to use and it performs the launch (mathematically speaking). According to RockSim, the Bullet, as I have it, will apogee around 745 feet with the G40W that I plan to use. The peak velocity will be about 200 feet / second and peak acceleration will be 175 feet / sec^2. That's about 5G.

I may want to pull off the electronics bay occasionally: the Bullet would then apogee over 1000 feet and hit nearly 250 feet / second with 6.8G. Or perhaps I'll attempt a Level 1 cert with the extended Bullet using an H55W: 2000 feet averaging 350 feet / second but only 4.5G... or burst off with an H180W: 2000 feet averaging 438 feet / second at 21G! Would be silly to fly an H without an electronics bay. With a Level 1 cert completed, I could then put an I in... too scary to even simulate. :)

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