压缩性对计算空化装置噪声的影响（英文）

The Effect of Compressibility in Computing Noise Which Induced at a Cavitating Device

通过应用混合方法可以简化噪声预测。计算流体动力学计算可以通过求解可压缩或不可压缩的Navier-Stokes方程来确定噪声源的流场变量来完成。正确的假设取决于物理情况和马赫数。虽然在诸如空化孔的空化装置中,通常我们处理的是低马赫数流量,但是空化是一种声学现象并且可能受到可压缩性的影响。在这项研究中,使用大涡模拟(LES)和Ffowcs Williams-Hawkings(FW-H)公式研究了压缩性在计算空化单孔孔口产生的噪声中的作用。这项工作的结果表明,压缩性在计算空化孔口产生的噪声方面具有重要作用,尤其是在研究低频空化状态下产生的噪声。

Noise prediction can be simplified by application of hybrid approach. The computational fluid dynamics calculation can be accomplished by solving either compressible or incompressible Navier- Stokes equations to determine the flow-field variables of the noise source. The proper assumption depends on both the physical situation and the Mach number. Although, in cavitating devices such as a cavitating orifice usually we are dealing with low Mach number flow but cavitation is an acoustic phenomenon and can be affected by compressibility. In this study, the role of compressibility in computing noise generated at a cavitating single- hole orifice was investigated using large eddy simulation (LES) and FfowcsWilliams-Hawkings (FW-H) formulation. The results of this work demonstrate that the compressibility has a significant role in terms of computing noise generated at a cavitating orifice and cannot be ignored, especially when the noise generated by developed cavitation regimes at low frequencies is investigated.