Computational Investigation of Damage by High-Speed Droplet Impact

The role of compressibility on impacts produced by high-speed (supersonic/hypersonic) liquid droplets is not well understood. The development of high-speed projectiles requires a better understanding of the forces imparted on the object and of the consequences of such impact. In this work, the impact of a 3D initially spherical water droplet at Mach numbers greater than 1.5 on a rigid wall is computationally investigated. Numerical simulations are performed using a high-order accurate, shock- and interface-capturing scheme with adaptive mesh refinement. As the speed of the droplet increases, the role of compressibility becomes increasingly important and the potential for damage increases. Larger droplet Mach numbers lead to pressures greater than the pressures found by the water hammer shock equation. The location of the maximum pressure seen on the wall is found to be away from the center of the impact, potentially due to local compression of the liquid. The size of the damaged region is inferred from the wall pressures.