Influence of turbulence closure models on the vortical flow field around a submarine body undergoing steady drift

Abstract

Manoeuvring underwater vehicles experience complex three dimensional flow. Features include stagnation and boundary layer separation along a convex surface. The resulting free vortex sheet rolls up to form a pair of streamwise body vortices. The track and strength of the body vortex pair results in a nonlinear increase in lift with as body incidence increases. Consequently, accurate capture of the body vortex pair is essential if the flow field around a manoeuvring submarine and the resulting hydrodynamic loading is to be correctly found. This work highlights the importance of both grid convergence and turbulence closure models on the strength and path of the crossflow induced body vortices experienced by the DOR submarine model at an incidence angle of 15 • . Five turbulence closure models are considered; Spalart-Allmaras, k − ε, k − ω, Shear Stress Transport and the SSG Reynolds stress model. The SSG Reynolds stress model shows potential improvements in predicting both the path and strength of the body vortex over standard one and two equation turbulence closure models based on an eddy viscosity approach.

Numerical investigation of a fleet of towed AUVs

“…The shear stress transport (SST) turbulence closure model (Menter, 1994) which blends k − ǫ and k − ω was selected for this study. Previous investigations have shown that it is better able to replicate the flow around the ship and submarine hull forms than either k − ǫ or k − ω model, notably with a moderate computer accuracy (Larsson and Baba, 1996;Phillips et al, 2010b).…”

Numerical simulation of flow around a body of revolution with an appendage controlled by electromagnetic force

“…Alin et al 1 and Toxopeus 2 calculated the flow field around bodies of revolution with different appendages using several turbulence models. Phillips et al 3 investigated the influence of turbulence closure models on the strength and path of the crossflow-induced body vortices of body of revolution at an incidence angle of 15 .…”

Application of the VORTFIND algorithm for the identification of vortical flow features around complex three‐dimensional geometries

“…It is worth highlighting that for many typical flows around marine vehicles, the user has sufficient elements to resolve the boundary layer and off‐body vortex structures to a level where selection of turbulence model also has a significant impact on the downstream evolution of the vortex. Selection of standard isotropic two‐equation models leads to more rapid dissipation of vortical structure, compared with Reynolds Stress Models . The generation of a suitably efficient, high quality mesh is not a simple task because the path, strength and radius of the vortex is not known a priori.…”