Presenting the calculation process of pitch and roll damping coefficients for a projectile in various flight conditions with numerical method

Computation of flight trajectory and autopilot design are important issues in design of flying objects, requiring accurate calculation of aerodynamic, esp. dynamic, coefficients. This article discusses a general process of calculating roll and pitch damping coefficients with CFD, which can be used to calculate roll and pitch damping coefficients for all flying objects and projectiles. These coefficients are extracted by using Fluent software as well as dynamic mesh techniques. This article also contains grid and turbulence modeling studies to provide appropriate turbulence model for each of these coefficients. In this process, roll and pitch moment coefficients are first extracted by dynamic mesh techniques in Fluent, and then, the dynamic coefficients are computed by using relations that are presented in this article. In order to validate the process, the dynamic coefficients for a projectile are computed and results are weighed against those obtained by foreign valid articles. Acceptable agreement between the results of current work and those of valid references demonstrates the accuracy of the process presented in this article to compute dynamic coefficients.