Thermodynamic effects on cryogenic cavitating flow in an orifice

Abstract

Temperature depression in a cavitating orifice flow was experimentally investigated with liquid nitrogen in order to clarify the influence of turbulent flow around a bubble on thermodynamic effects on cavitation. The temperature began to decrease at the outlet of the orifice when the cavitation number decreased below 0. Moreover, the temperature depression became larger as the cavitation number became smaller. In addition, the temperature depression also became greater as the flow velocity became lower when the cavitation numbers were equal. Based on theoretical considerations and experimental results, the difference of temperature depression can be considered to be caused by the enhancement of thermal transport around bubbles due to the turbulent flow. In addition, if thermal transport is enhanced as mentioned above, the temperature in the area where the cavitation collapses can become higher than that upstream of the orifice due to the temporary breakdown of the heat balance between the inception and collapse of cavity bubbles.http://deepblue.lib.umich.edu/bitstream/2027.42/84237/1/CAV2009-final36.pd