Numerical and Experimental Investigation of the Tip Vortex Flow Induced by an Elliptical Foil

This collaborative paper within the AVT-320 joint research activity compares Computational Fluid Dynamics (CFD) results from diverse methods across research partners, validated against Experimental Fluid Dynamics (EFD) investigations in two test facilities. Focusing on non-cavitating tip vortex flows using an elliptical foil as a test case, the study reveals flow fluctuations and highlights the synergy between research institutions and advanced measurement technologies. The evaluation of CFD methods, including hybrid RANS/LES-numerical approaches, provides insights into turbulence modeling for tip vortex flows. Strong interactions between the tip region and trailing edge flow are observed, contributing to refining our understanding of these complex fluid dynamics. The study includes a comprehensive analysis of the tip vortex behavior of the the elliptical foil NACA 662 -145, which has been investigated over the past three decades. The collected data encompasses the distribution of 19 flow variables on 17 cross sections, with a detailed analysis and comparison performed on four planes. Experimental results elucidate the effects of wandering correction on variable distribution. Two approaches to model turbulence are employed in CFD computations: scale-resolved simulation models to characterise the local flow and the eddy viscosity-based k − ω SST model. The hybrid turbulence model ensures consistency in velocity and pressure in the core region, serving as a robust reference for cavitation inception.