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Re: Advices to simulate turbulent channel flow


Hi Mathias,rnrnThank you for quick reply. rnrnAccording to the turbulence model, I should use the Shear-Smagorinky model with the “”normal”” parameter (Cs = 0.16-0.13) in order to take into account the presence of the wall, where the Smagorinsky parameter tends to decrease.rnrnThe body force term (gravity in this case) have been decomposed in its x/y directions according to the slope of the channel. The simulation diverges when I take in account both directions (in my case “”y””). So, I use just the horizontal component. Do you know which could be the problem? Do I not compute the gravity body force term right? Should I just take into account the horizontal direction of this force because I do not use a “”Volume-of-Fluid”” approach in order to simulate the water level variation ?rnrnPreviously, I used a smooth start curve (PolynomialStartScale<T,T>) in order to begin from a Re = 300 to Re = 3000. All along the simulation I used the shear-smagorinsky turbulence model. However, the simulation diverged. Is it necessary to begin the simulation at low Re without a turbulence model and then to switch to moderate Re with a turbulence model for low spatial resolution?rnrnBest Regards,rnrnAlejandrornrn