Numerical simulation of a spinning stabilized projectile aerodynamic characteristics effected by structure errors

Based on the (Shear Stress Transport) SST k-ω turbulent model, the effets of vehicle′s model with structure errors are investigated using computational fluid dynamic (CFD) method. Firstly, the aerodynamic coefficients of the model without structure errors are calculated in the conditions of different Mach numbers and spinning speeds, and the results are compared with that of the experimental data. CFD calculations predicted the drag, normal force, pitching moment, and normal force center of pressure very well, and their errors are within 10% of the experimental data which verified the accuracy and feasibility of the CFD output. Then, the models without structure errors and the models with structure errors including projectile′s mass asymmetry and coaxial error are established, and their aerodynamic characteristics are numerically calculated by CFD. The results shown that the model of mass asymmetry have a great influence on its roll damping coefficient and magnus moment coefficient derivative, and the model with coaxial error have a great influence on its normal force coefficient derivative, pitching moment coefficient derivative, magnus moment coefficient derivative and center of pressure location. Projectiles′ aerodynamic characteristics coefficients may have a prodigious change due to structure errors, and the flight stability of the model may be effected by these coefficients′ prodigious change. The flight trajectory and stability also will be affected accordingly.