Free Courses

[FAQ]

When running the SBES model, the “Shielding function for SBES” switches between the RANS (=1) and the LES (=0) region. The “Blending Function for DES model” does not enter into the turbulence model, but switches the numerical treatment from Upwind Biased (=1) to Central difference (=0). The name is historic – it should be called “Blending Function for Numerics”. The numerics blending is taken over from the DES model (CFX-Thoery documentation: 2.6.4 “Discretisation of the Advection Terms). A closer agreement of the numerics blending to the enhanced model blending of the SBES formulation can be enforced by changing the default value of the model parameter: C DES for k epsilon Regime = 0 (default is 0.61) RULES: SINGLETON: SBES COEFFICIENTS Solver Name = SBES Description = Controls blending between LES and RANS for SBES turbulence model. Optional Parameter List = C Shielded DES, Csdes, C DES for k omega Regime, C DES for k epsilon Regime END END FLOW: Flow Analysis DOMAIN: fluid FLUID MODELS: TURBULENCE MODEL: Option = SBES SST SBES COEFFICIENTS: C DES for k epsilon Regime = 0 END END END END END