The Presentation of a Mathematical Model for Aerodynamic Coefficients Extraction in Supersonic Aeroballistics Projectile Test

The precise method for aerodynamic parameters measurement in aeroballistics labs, is the free flight method. It can be used to test different models at a wide range of flight speeds including subsonic, transonic, supersonic and hypersonic speeds, and in the millimetric to metric range dimensions. It can be utilized to measure the path-equation related parameters and the aerodynamic and aeroelastic parameters. Moreover, it has the capability for checking the performance of designed control systems, testing material temperature tolerance, testing structural strength and addressing high-speed collision and re-entry problems. In this lab, stations for measuring flight model data are located at certain distances that extract data using imaging and telemetry techniques. The main goal is to provide a suitable mathematical model with precise accuracy in order to extract aerodynamic coefficients from raw data measured according to the number of measurement stations and their intervals. Therefore, for the purpose of using imaging data, an overview of aerodynamic coefficients extraction in the aeroballistics test is carried out. The results show that static and dynamic coefficients are not independent in extraction and should be calculated simultaneously. Dynamic coefficients cannot be ignored if the magnitudes are significant. The measurement accuracy required when the dynamic coefficients cause the damping of the oscillations is about 0.1 degree with 20 stations, while the accuracy of 0.1 degree with 10 stations is inadequate and higher than that is required.