A Numerical Study of Forces in High-Speed Droplet Impact

High-speed droplet impact can be a serious threat to the structural integrity of flight vehicles, yet this problem lacks understanding. The forces exerted in high-speed droplet impacts have been rarely investigated, whilst forces in low-speed impacts are very well characterized. A five equation model based diffuse interface method is used to conduct three investigations: firstly, effect of equation of state, secondly, effect of Mach number, and thirdly, effect of two droplets in tandem impact. The results show that the equation of state affects the jet speed and the peak force, the force-time profiles for initial impact loading can be generalized across Mach numbers using water shock based reference time scale, and the second droplet in the tandem impact may apply a higher peak force than the first droplet.