Liquid-liquid mixing for the breakup of accelerating drops

Studies have been made on the fragmentation of liquid metal drops falling through a waterglycerine mixture containing small amounts of nitrogen bubbles owing to the passage of a strong shock wave. The apparent drop volume increased with lime, but neither stripping of small droplets nor misty wake formation was observed in the high-speed photographs. The drop flattened initially into a spherical cap which increased in radius, but remained smooth, within the time period of interest. Hence the Taylor instability is not the principal fragmentation mechanism at these Weber numbers (5-644). Entrainment of liquid into the drop was the cause of breakup, and was postulated to be due to turbulent mixing resulting from vorticity generation near the plane of separation. A hydrodynamic fragmentation model was developed which predicts the rale of drop volume increase reasonably well. The breakup time constant was presented, and drop trajectory can also be predicted from the model.