Observations of high temperature impinging-jet boiling phenomena

A high-speed video camera and microphone were used to capture the flow behavior and boiling sound of a free-surface water jet impinging on a high temperature surface during quench cooling. It was found that depending on the superheat of the surface considerably different flow patterns appeared. For cases where the initial surface temperature was above about 300 °C an almost explosive pattern appeared. This was in contrast to slightly lower temperatures where a liquid sheet flow structure was apparent. The change in phenomena was accompanied by a sudden change in the boiling sound and an increase in the heat transfer rate.