Prediction and Analysis of the Aerodynamic Characteristics of a Spinning Projectile Based on Computational Fluid Dynamics

Abstract

Numerical simulations of a spinning projectile with a diameter of 120 mm were conducted to predict the aerodynamic coefficients, and the CFD results were compared with the semiempirical method, PRODAS. Six coefficients or coefficient derivatives, including zero and the quadratic drag coefficient, lift force coefficient derivative, Magnus force coefficient derivative, overturning moment coefficient, and spinning damping moment coefficient, which are important parameters for solving the equations of motion of the spinning projectile, were investigated. Additionally, the nonlinear behavior of these coefficients and coefficient derivatives were analyzed through the predicted flow fields. The considered Mach number ranges from 0.14 to 1.2, and the nondimensional spinning rate (PD/2V) is set to 0.186. To calculate the coefficient derivative of the corresponding force or moment, additional simulations were conducted at the angle of attack of 2.5 degrees. The simulation results were able to predict nonlinear behavior, the especially abrupt change of the predicted coefficients and derivatives at the transonic Mach number, 0.95. The simulation results, including the skin friction, pressure, and velocity field, allow the characterization of the nonlinear behavior of the aerodynamic coefficients, thus, enabling better predictions of projectile trajectories.

Comparison of Real and Simulation Aerodynamic Coefficients for 155 mm Ammunition Using Open-Source Code SU2 Software

“…When the velocity of the ammunition is approximately 340 m/s (1 Mach) and above since the air cannot move faster than the bullet due to its inertia, the air becomes compressed in front of the ammunition, and its density increases. Therefore, parallel to the literature [25], it was determined that the angles of the pressure waves at the ammunition nose level at speeds above Mach 1 decrease due to the compressed and increasing density of the air and that the shock wave curve turns into a narrow-angle starting from the direction of the movement direction and starting from the line of the ammunition nose up to Mach 2.8 supersonic speed. In addition, it was determined that the turbulent flow inclination behind the ammunition, which occurs in the subsonic flow region, is high.…”

Numerical study of freestream turbulence effects on the nose cones in supersonic flow

“…This is mainly due to the early transition of the boundary layer that causes the elevation of skin friction drag on the surface. It is noticed that the coefficient of drag varies linearly for the spherically blunted nose cone while somewhat nonlinearly for the parabolic nose cone due to effect of skin friction drag flucations (Ko et al , 2020). This clearly depicts that the influence of shock wave and turbulence interaction mainly depends on the shape of the nose cone: …”

Numerical Simulation of Chemical Storage Tank Area Leakage and Explosion Accident Based on FLACS

“…e arrangement of combustible gas detectors should conform to the law of gas di usion, but the external environmental conditions such as wind direction, wind speed, and temperature, as well as the obstruction of equipment in the tank area make the process of gas leak di usion more complicated. e development of information technology [3][4][5][6][7], computational uid dynamics (CFD) [8][9][10][11][12], and their integration has brought new opportunities to numerical simulation of chemical storage tank area leakage and expansion accident.…”