Numerical Investigation of Cloud Cavitation and Its Induced Shock Waves
Numerical Investigation of Cloud Cavitation and Its Induced Shock Waves
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云空化及其诱发冲击波的数值研究
DOI：
10.1115/fedsm2021-65731
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Hiroaki Yoshimura
中科院分区：
文献类型：
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作者：
Takahiro Ushioku;Hiroaki Yoshimura
本文对云空泡的非定常特性进行了数值研究，特别是对诱导激波的发射进行了研究。为此，我们考虑了淹没水射流通过喷嘴喷射到静水中，并通过Navier-Stokes方程对二维多相流进行了数值分析。在我们以前的研究[7]中，我们已经表明，双涡对称地出现在注入水中，这在执行气泡云的不稳定行为中起着至关重要的作用。本文进一步阐明了激波发射的基本过程。首先，我们用SPH方法建立了拉格朗日描述的气液混合物模型，并详细介绍了边界条件的处理。其次，我们给出了多相流的速度场来说明云的起源、增长和崩溃。特别是，我们解释了云的崩溃的机制，鉴于双涡的运动。此外，我们调查的压力场的多相流，以证明如何发射的冲击波与崩溃的云。最后，我们表明，一个小的冲击波可能会被释放之前的主要冲击波发射。
This paper numerically investigates unsteady behavior of cloud cavitation, in particular, to elucidate the induced shock wave emission. To do this, we consider a submerged water-jet injection into still water through a nozzle and make some numerical analysis of two-dimensional multiphase flows by Navier-Stokes equations. In our previous study [7], we have shown that twin vortices symmetrically appear in the injected water, which plays an essential role in performing the unsteady behavior of a cloud of bubbles. In this paper, we further illustrate the elementary process of the emission of the shock waves. First, we set up the mixture model of liquid and gas in Lagrangian description by the SPH method, together with the details on the treatment of boundary conditions. Second, we show the velocity fields of the multiphase flow to illustrate the inception, growth as well as the collapse of the cloud. In particular, we explain the mechanism of the collapse of the cloud in view of the motion of the twin vortices. Further, we investigate the pressure fields of the multiphase flow in order to demonstrate how the shock wave is emitted associated with the collapse of the cloud. Finally, we show that a small shock wave may be released prior to the main shock wave emission.