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The Influence of Turbulence Model on Wake Structure of TSTs when used with a Coupled BEM-CFD Model. Ian Masters, R. Malki, Alison Williams & Nick Croft Marine Energy Research Group Swansea University. Modelling Approach. Moving Mesh Approach. Time-averaged Approach.
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The Influence of Turbulence Model on Wake Structure of TSTs when used with a Coupled BEM-CFD Model Ian Masters, R. Malki, Alison Williams & Nick Croft Marine Energy Research Group Swansea University
Modelling Approach Moving Mesh Approach Time-averaged Approach Source: A. Mason-Jones , PhD thesis Cardiff University (2010)
Model Domain 0.17m 1.54m 0.84m 0.5m 0.25m 0.17m 0.5m 0.84m 1.4m
95% Wake Edges P95% P∞ PWAKE P∞
Turbulence Models k-epsilon • Eddy viscosity from single length scale • Turbulent diffusion occurs only at specified scale RNG k-epsilon • Account for different scales of motion k-omega • Viscous sub-layer flows • Adverse pressure gradients and separating flows
Turbulence Models Shear Stress Transport (SST) • k-ω near boundary • k-ε in free-stream • Adverse pressure gradients & separating flows Reynolds Stress Model (RSM) • Reynolds Stresses directly computed • Directional effects of Reynolds stress fields • More suitable for anisotropic turbulence
Conclusions • Turbulence Models affect Hydrodynamics • Lack of Measured Data for Validation • Possibly better represent turbulence