Computational study of high-speed liquid droplet impact

We are investigating the fluid dynamics of high-speed (500 m/s) small size (200 μm in diameter) droplet impact on a rigid substrate. Utilizing a high-resolution axisymmetric solver for the Euler equations, we show that the compressibility of the liquid medium plays a dominant role in the evolution of the phenomenon. Compression of the liquid in a zone defined by a shock wave envelope, very high velocity lateral jetting, and expansion waves in the bulk of the medium are the most important mechanisms identified, simulated, and discussed. Comparisons of computationally obtained jetting inception times with analytic results show that agreement improves significantly if the radial motion of liquid in the compressed area is taken into account.