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以水的气化压力(Pv)作为判别水流初生空穴的临界压力,以及在此基础上建立的计算初生空穴指数的托马公式σ_1=P_∞-P_v/1/2ρV2,迄今仍在气蚀研究中普遍使用。但是大量的试验结果证实,σ_1常常是不稳定的,即使同一个扰流体本身的σi也可能有高达三倍以上的差别。合理的空穴临界压力不应仅仅只与温度有关,而且还应与杂质及气体含量、压力、流速、史前条件等因素有密切的关系。本文将叙述用抗拉强度(P_T)作为临界压力的物理基础和实际应用的可能性(以公式(?)计算初生空穴指数的初步研究成果。)
The vapor pressure (Pv) of water is taken as the critical pressure to discriminate the primary hole of water flow, and the Toma formula σ_1 = P_∞ -P_v / 1 / 2ρV2 which is used to calculate the primary hole index is still in the air Erosion studies are commonly used. However, a large number of experimental results confirm that σ_1 is often unstable, and that the σi of the same disturbing fluid itself may be as high as three times higher. Reasonable hole critical pressure should not only only be related to temperature, but also with impurities and gas content, pressure, flow rate, prehistoric conditions and other factors are closely related. This article will describe the physical basis of tensile strength (P_T) as a critical pressure and the possibility of its practical application (preliminary results of the calculation of primary hole index by the formula (?)).