绕细长体空化器的垂直超空化流分析

Analysis of vertical supercaviting flow around slender cavitator

对于绕轴对称细长体空化器的超空泡流问题,提出了一种积分方程方法.用奇异性离散化方法对积分方程进行了求解.在垂直来流时,考虑了Froude数对定常和非定常超空泡长度和形状的影响;比较了不同形状细长空化器的超空泡长度和横截面尺寸.应用时间有限差分离散化方法,计算了空化数变化时超空泡形状和长度的非定常变化.计算表明,空泡的形状变化具有时间滞后性和波动性.用Logvinovich空泡横截面独立膨胀原理对扰动波形沿空泡表面的传播过程作了定性分析.

A method of integral equation to calculate a length and shape of axisymmetric steady and unsteady supercaviting flow around axisymmetric slender cavitator is developed. The integral equation is solved using singular discretization numerical method. In case of vertical incoming flow, the effection of grivaty on steady and unsteady supercavitaty shape and length is considered. The supercavity shapes and length introduced by cavitatior of different shapes is compared. The unsteady supercavity shape and length is calculated by using the finite difference time discretization when cavitation number changes. Calculation shows that the unsteady behavior of supercavity shape have properties of time lag and of wave-shape oscillations. The propagation of unsteady perturbed wave shape along cavity surface is analyzed qualitatively based on G. V. Logvinovich＇s principle of independence of the cavity section expansion.