A numerical investigation concerning wall-nucleation effects of the inception of sheet cavitation

Abstract

In this study, a multiscale Euler–Lagrange method is proposed, integrating a new wall nucleation model tailored for predicting sheet cavitation dynamics. Differentiating from the previous homogeneous wall nucleation model, our approach calculates nucleation diameter based on local flow conditions. Specifically, within the flow attachment region, the nucleation diameter is dependent on the flow shear rate, whereas in separation zones, it correlates with the thickness of the low-momentum region. Transition corrections are incorporated into the delayed detached eddy simulation (DDES) model to enhance accuracy in predicting flow separation. Rigorous validation is conducted, focusing on Lagrangian bubble dynamics and predicting laminar separation. The method is then applied to investigate cavitation flow induced by an axisymmetric headform body. Predicted cavitation scenarios are compared with experimental observations, Euler cavitation simulations, and multiscale simulations employing the wall nucleation model introduced by Hsiao et al., (2017). Results demonstrate that our model accurately predicts cavity morphology and inception index, closely matching experimental findings. Moreover, our model offers a coherent explanation for the detachment position and inception index of sheet cavitation, emphasizing the pivotal role of wall nucleation in precise prediction of sheet cavitation phenomena.