Detached-Eddy Simulations for Cavitating Flows

The horseshoe vortex generated around the sail-body junction of submarine has an important influence on the non-uniformity of submarine wake at propeller disc. The flow characteristics in the horseshoe vortex generated area are analyzed, and a new method of vortex control baffler is presented. The influence of vortex control baffler on the flow field around submarine main body with sail is numerically simulated. The wind tunnel experiment on submarine model is carried out, and it is proved that the vortex control baffler can weaken the horseshoe vortex and decrease the non-uniformity of the wake at propeller disc. It is shown from the experiment results that the effect of vortex control baffler depends on its installation position; with a proper installation position, the non-uniform coefficient of submarine wake would be declined by about 50%; the Reynolds number of submarine model has an influence on the effect of vortex control baffler too, and the higher the Reynolds number is, the better the effect of the vortex control baffler is.

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“…Refs. [10][11][12]). As the state-of-thepractice of CFD progresses toward routine use of unsteady, time-accurate simulations, even for static configurations [5], DES might not be the panacea many expect it to be.…”

Section: Introductionmentioning

confidence: 97%

A Scale-Adaptive Variant of the Spalart-Allmaras Eddy-Viscosity Model

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2015

22nd AIAA Computational Fluid Dynamics Conference

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A method is presented for introducing scale-adaptive capabilities into the SpalartAllmaras one-equation turbulence model that allows it to resolve large-scale turbulent flow features. Unlike detached-eddy simulation, scale-adaptive methods dynamically respond to the resolved turbulent content without an explicit dependency on the local grid size, and the compatibility of the relevant length scales makes it more resilient to modeled stress depletion. The formulation is based on existing scale-adaptive models, comparisons of the relevant length scales in boundary-layer flows, and the desire to preserve the existing steady RANS capabilities of the model when appropriate. Results are presented that demonstrate the capabilities of the scale-adaptive Spalart-Allmaras variant and are compared to results using traditional unsteady RANS and detached-eddy simulation. Nomenclatured = distance to nearest wall k = turbulent kinetic energy L = turbulent length scale LvK = von Karman length scale Re = Reynolds number Reθ = momentum-thickness Reynolds number S = strain-rate magnitude uj = Cartesian velocity component xj = Cartesian coordinate Δ = characteristic grid size ε = turbulent dissipation κ = von Karman constant μ = molecular viscosity μt = turbulent eddy viscosity ν = kinematic viscosity  = modified eddy viscosity Ω = vorticity magnitude ω = turbulent specific dissipation

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Detached-Eddy Simulations for Cavitating Flows

Cited by 19 publications

References 3 publications

Numerical simulation and control of horseshoe vortex around an appendage–body junction

Numerical simulation and control of horseshoe vortex around an appendage–body junction

Experimental study on effect of a new vortex control baffler and its influencing factor

A Scale-Adaptive Variant of the Spalart-Allmaras Eddy-Viscosity Model

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