From supercritical hydrodynamic expansion to explosive phase change: Thermodynamic evolution of water during its interaction with high-intensity infrared nanosecond-pulsed laser

A predictive hydrodynamic model has been developed for high-intensity infrared nanosecond laser-water interactions. The model is first tested by comparing with experimental measurements for laser-induced pressure and shock wave propagation. Then the verified predictive model is applied to quantitatively understand the water thermodynamic state evolution, which has not been sufficiently studied in literature. It has been found that for the studied intense infrared nanosecond laser-water interaction, the major phase change process during the early stage is the supercritical hydrodynamic expansion followed by an explosive phase change process that occurs as the water thermodynamic-state curve approaches (from outside the binodal curve) and starts touching the critical point in the phase diagram. The model shows that the explosive phase change occurs at a delay time of similar to 150 ns after laser pulse starts, which is quantitatively consistent with previous experimental observations.