[hx293]

Hello everyone,

I just started learning CFD with the channel flow case. I tried different RANS models and LES SGS models on predicting the velocity profile at the channel outlet, and I found most RANS results agreed well with former experiments and DNS results, but LES results did not.

Is there any idea why the LES results deviate the exp. and DNS results so much?

Attached figs contain results and illustrations of the BC settings. The Reynolds number of the problem (defined by channel height and velocity at the channel center) is around 10,000, and the simulated channel length is enough to reach fully developed turbulent flow at channel outlet. The y+ value of the near wall mesh is around 0.2. The delta x+ (streamwise) value of the near wall mesh is around 6, and the delta y+ (pitchwise) value is around 4. The solver I used is Fluent.

Thank you for your attention.