初生空化数公式的优化研究

Optimization research of incipient cavitation number formulas

初生空化数是衡量过流体型是否发生空化的判别标准。传统的托马公式认为液流负压值达到液体饱和蒸汽压时即发生空化。近来研究表明,气核和液体抗拉强度等对初生空化有重要影响。有学者认为把托马公式中的液体饱和蒸汽压替换为临界压强更为合理。本文在已有研究的基础上,对空化初生机理和影响空化初生的因素进行分析。认为空化仅是气核克服表面张力和液体饱和蒸汽压膨胀而形成的,并没有克服液体抗拉强度,且在空化源附近的液体几乎不具有抗拉强度,并基于此提出新的初生空化数公式。

The incipient cavitation number is a measure of the fluid through the criterion whether the occur-rence of cavitation type.Thomas traditional formula that considers the flow of negative pressure occurs when the liquid reaches the saturation vapor pressure cavitation.Recent studies show that the gas core and liquid cavita-tion tensile strength have a significant impact on newborn.Some scholars believe that the Thomas saturated va-por pressure of a liquid formula to replace the critical pressure is more reasonable.Based on existing research on the mechanisms and effects of cavitation inception cavitation inception factors were analyzed.Cavitation is considered only nuclear overcome the surface tension of gas and liquid saturation vapor pressure of the expan-sion and the formation of the liquid does not overcome the tensile strength and cavitation near the source of the liquid has almost no tensile strength ,and based on this proposed new born cavitation number formula.