Cavitation Inception in Still Water Caused by Gradually Decreased Static Pressure : (Effects of Air Content and Temperature in Water)

Abstract

Cavitation is principally considered to occur when the pressure is reduced to a certain critical value and is maintained for a certain duration. The present study is therefore intended to investigate an extreme case of maintaining the low pressure for sufficiently long duration. To do this, the pressure in a sealed water container is gradually lowered so as to produce cavitation. The air content and the temperature of the water are systematically varied. The results of the investigation can be summarized as follows. (1) The pressure at the cavitation inception is nearly equal to or less than the published data of vapor pressure of water, and decreases with the air content in water. (2) The superheat increases with decreasing water temperature, and the difference between the vapor pressure and the inception pressure increases with the temperature.