Numerical Simulation on Aerodynamic Characteristics of Projectile in Rainstorm Environment

Abstract

In order to study the influence of rainstorm conditions on the aerodynamic performance of projectiles, the computational fluid dynamics method was applied to carry out numerical simulation under extreme rainstorm conditions. The flow field was numerically simulated by solving three-dimensional steady compressible Navier-Stokes equation and k-? turbulence model. The trajectory of discrete raindrop particles in the flow field was traced by two-way momentum coupled Eulerian-Lagrangian method. The random diffusion effect of raindrop particles caused by airflow turbulence and the interaction between raindrop particles and projectile surface were considered. The effect of liquid water content on the aerodynamic parameters of M910 projectile and 120 mm mortar projectile was studied at different angles of attack. The results show that the rainstorm has a great influence on the lift coefficient of the two projectiles. When Ma=0.7, the maximum lift coefficients of M910 projectile and 120 mm motar projectile decrease by 14.5% and 21.9%, respectively. The influence degree decreases gradually with the increase of the angle of attack, and the resistance coefficient of the two projectiles is less affected by the rainstorm. Affected by the tail, the influence of rainstorm on the mortar projectile(fin-stabilized projectile)is higher than that of the M910 projectile(spin-stabilized projectile). The non-uniform water film formed on the surface of the projectile and the momentum loss at the boundary of the projectile caused by the collision of raindrop particles are the main reasons that affect the aerodynamic performance of the projectile.