Chapman-Kirk Reduction of Free-Flight Range Data to Obtain Nonlinear Aerodynamic Coefficients
ARMY BALLISTIC RESEARCH LAB ABERDEEN PROVING GROUND MD
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The Chapman-Kirk technique for obtaining the parameters in a system of differential equations was applied to time, position, and orientation measurements taken along the trajectories of twelve rounds fired in the BRL transonic Range. The twelve rounds represent four spin-stabilized projectile types the M71, the M329A1 with and without extension and the M329A1E1. The rounds were previously reduced at BRL by standard, linear reduction techniques the Chapman-Kirk reduction was carried out by the General Electric Company under contract to BRL. A comparison of the BRL and GE results shows good agreement in the linear coefficients. The Chapman-Kirk technique has the advantage - particularly for large yaw rounds, where linear analysis breaks down - that it can determine from a single trajectory the values of the nonlinear coefficients present in the equations of motion.
- Ammunition and Explosives