A Burn Model Updated

I decided to put together a simplified burn model to incorporate into the Android App I put together for re-loading and exterior ballistics calculations. It gives me a little better feeling for the overall veracity of the application. The powder mass function was developed with a 4th order Runge-Kutta scheme which can be found in the Open Calculators downloads section of the blog. The velocity was derived from a lumped parameter energy balance model. I used a thermochemical solver for developing some of the powder constants. I'll probably put together a thermochemical solver for here which will also be useful for detonation and explosive properties calculations which I plan to write about in the future.

Powder Mass and Projectile Velocity From The Burn Model

Pressure-Time

The model is set up to burn nearly all (~98%) of the material when the projectile is very close to it's initial position. In this manner it acts almost as pre-burned gun system. The dt and beta terms are chosen such that the total time of interest is relevant to the problem and the beta burns the material at the appropriate rate to achieve the "hardly moved" state.

I have made the burn model a little easier to use, and a little less cluttered. It can be found in the Open Calculators Section of the Google Drive under Consolidated Burn Model.