## 1 Introduction
[13] verified the effectiveness of numerical methods by comparing the RANS results obtained from the commercial code, STAR-CCM+, with those obtained from the experiments in the large cavitation tunnel (LCT) of Korea Research Institute of Ships and Ocean Engineering (KRISO). The effects of the wall boundary layer profile on the contraction part of the LCT, located before the test section, were analyzed by applying the same flow distribution as the measured one on the inlet flow of the test section. Then, the wake distribution, propulsion performance, and cavitation phenomena of several propellers were estimated to focus on the hull effects. In addition, the influence of turbulence models on the TVC of a NACA662-415 elliptical wing was also investigated. It was found that the use of the realizable k-\(\epsilon\) model resulted in the overestimation of the turbulence viscosity inside the TVC by over-predicting the turbulence production. However, the Reynolds stress model (RSM) well described the vortex structure and variation in flow momentum by accurately predicting the laminar region inside the vortex core [14]. [PERSON] et al. [15] performed the LES simulation using open-source code, OpenFOAM, to simulate the TVC of the elliptical wing of NACA662-415 cross-section and compared the simulation results with the measure ones. The Rayleigh-Plesset equation and the minimum pressure criterion based on the single bubble assumption were used to predict the cavitation inception, which revealed the importance of the water quality effect affecting the nuclei distribution. [PERSON] et al. [16] simulated the tip leakage cavitation of a NACA000 wing using the LES and analyzed the interaction between tip leakage vortex and tip-separated vortex structures in terms of Lagrangian coherent structures. It was shown that the combination of two vortex structures generated the induced vortex, and the stretching effect of vorticity was dominant in the tip leakage cavitation flow. [PERSON] et al. [17] simulated the cavitation flow on the sharp wedge using the compressible LES and homogeneous mixture assumption. The periodic pattern from cavitation generation to collapse was described. Re-entrant jet and bubbly shock wave during the transition from the sheet cavitation to the cloud cavitation were observed. Notably, it was confirmed that the supersonic flow was instantaneously formed when bubbles were collapsed, and the bubble shock wave was triggered by a compression wave generated through the disappearance of the detached cloud cavitation. [PERSON] et al. [18] investigated the designs to delay cavitation inception in the impeller using the three-dimensional incompressible RANS. The impeller wing was simplified to a NACA0006, of which the cavitation inception was compared by varying the design parameters such as the long-short axis ratio of elliptical leading edge shape, the thickness diffusion angle, and the exponent of thickness diffusion angle. It was found that, as the leading edge shape is closer to the thick ellipse, not the arc, cavitation inception was delayed at the cost of loss of less than 5% in hydrodynamic performance. Because LES requires a lot of computational resources and time, it is difficult to carry out the simulation effectively at the design stage. This is why RANS simulations are widely used. However, it is challenging to accurately reproduce the vortex structure convected in the downstream direction without enormous numerical cost by using the RANS solvers. It suffers from being numerically attenuated during its convection, which is caused by two reasons: one is the numerical damping intrinsic to the difference equations obtained in the discretization process of the original governing partial differential equations, and the other is excessive turbulence intensity caused by the use of the turbulence model. This problem can be mitigated by using high order schemes, enough grids, and a high-accuracy turbulence model, but it requires as much computational cost as the LES [15].