Simulation on Flow around Cylindrical Projectile in Water Based on DES model

Based on the software Fluent, the flow around a cylindrical projectile in water with high Reynolds number is simulated by using the detached eddy simulation(DES) method. The flow characteristics of the cylindrical projectile are analyzed at the flow rate of 25 m/s, and the lift coefficient, the drag coefficient and the Strouhal number, as well as the periodic alternatively shed Karmen vortex structure, are obtained. The mean velocity of flow field in different cross section and the mean steady pressure coefficient at cylinder circumference are analyzed. The image law is well consistent with that from the known large eddy simulation(LES) method. Further, the projectile drag coefficient and the Strouhal number at different speeds are analyzed, and the results show that with the increase in flow rate, the drag coefficient and the drag against the cylindrical projectile moving in water decrease, while the Strouhal number increases, inferring higher frequency of vortex shedding at both sides of the cylindrical projectile. When the vortex shedding frequency is close to the natural frequency of the projectile, resonance will occur to harm the projectile. This research may provide reference for design of projectile in underwater weapon warhead.