初生空化数比尺效应的修正

Correction of incipient cavitation number for scale effect

在初生空化位置写出了随流运动的球泡动力方程， 估计了方程各项在空化初生时的近似值； 以现有的实测资料为依据， 选择了能识别的气核失稳的临界半径 Ｒｃ 的大小； 给出了原型初生空化数与模型初生空化数的简单关系式； 列出了碧口水库孔板洞４ 个不同比尺减压模型的实测初生空化数， 这些模型初生空化数的值相差很大， 但由这４ 个模型初生空化数和本文给出的换算关系得到的原型初生空化数很接近， 这原型初生空化数与原型观测结果定性一致．

Based on the dynamic equation of bubble, a simple relationship between incipient cavitaion number of prototype and model is established with the approximation of the terms in the equation taken into account. A typical radius of bubble during cavitation inception is determined according to the observation data. The relationship is verified by the model test results of a spillway tunnel with different scales.