High-speed visualization of interface phenomena: single and double drop impacts onto a deep liquid layer

Single and double drop impacts onto a deep pool were observed with a high-speed camera. The early stage of drop impact was investigated to detect the evolution of the interface between the fluid of the impacting drop and of the target pool. A new flow regime for the single drop impact was detected, due to a superposition of partial coalescence and crater formation. The closure of the crown above the crater was observed for some impact parameters. The submerged flow geometry generated by the simultaneous impact of two identical drops was also reported.