TY - GEN
T1 - Numerical investigation of cloud cavitation and its induced shock waves
AU - Ushioku, Takahiro
AU - Yoshimura, Hiroaki
N1 - Funding Information:
TU is supported by JST CREST (JPMJCR1914). HY is partially supported by Grants-in-Aid for Scientific Research (A) (17H01097), Waseda University Research Projects (SR 2019C-176, SR 2019Q-020), JST CREST (JPMJCR1914), MEXT Super Global University Creation Support, and the Organization for University Research Initiatives (Evolution and application of energy conversion theory in collaboration with modern mathematics).
Publisher Copyright:
© 2021 American Society of Mechanical Engineers (ASME). All rights reserved.
PY - 2021
Y1 - 2021
N2 - 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.
AB - 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.
KW - SPH method
KW - bubbly water-jet
KW - cloud cavitation
KW - collapse
KW - multiphase flow
KW - shock wave emission
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U2 - 10.1115/FEDSM2021-65731
DO - 10.1115/FEDSM2021-65731
M3 - Conference contribution
AN - SCOPUS:85116603678
T3 - American Society of Mechanical Engineers, Fluids Engineering Division (Publication) FEDSM
BT - Fluid Mechanics; Micro and Nano Fluid Dynamics; Multiphase Flow
PB - American Society of Mechanical Engineers (ASME)
T2 - ASME 2021 Fluids Engineering Division Summer Meeting, FEDSM 2021
Y2 - 10 August 2021 through 12 August 2021
ER -