Numerical Analysis of Tip Vortex and Cavitation of Elliptic Hydrofoil with NACA 662-415 Cross Section

Abstract

This paper provides quantification of the effects of the turbulence model and grid refinement on the analysis of tip vortex flows by using the RANS(Reynolds averaged Navier-Stokes) method. Numerical simulations of the tip vortex flows of the NACA 66 2-415 elliptic hydrofoil were conducted, and two turbulence models for RANS closure were tested, i.e., the Realizable k-ε model and the Reynolds stress transport model. Numerical results were compared with available experimental data, and it was shown that the data for the Reynolds stress transport model that were computed on the finest grid system had better agreement in reproducing the development and propagation of the tip vortex. The Realizable k-ε model overestimated the turbulence level in the vortex core and showed a diffusive behavior of the tip vortex. The tip vortex cavitation on the hydrofoil and its trajectory also showed good agreement between the current numerical results that were obtained using the Reynolds stress transport model and the results observed in the experiment.

Numerical Investigation of Tip Vortex Cavitation Inception and Noise of Underwater Propellers of Submarine Using Sequential Eulerian–Lagrangian Approaches

“…⊗ denotes the tensor product and = τ means the viscous stress tensor. The commercial code STAR CCM+ is used to numerically solve Equations ( 2) and (3) [12,14]. The numerical discretization is based on a finite volume-based solver.…”

“…It was found that the use of the realizable k-ε 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]. Asnaghi et al [15] performed the LES simulation using open-source code, OpenFOAM, to simulate the TVC of the elliptical wing of NACA66 2 -415 cross-section and compared the simulation results with the measure ones.…”