[bienxanh1901]

Hi everyone, I am running Echangeur geometry with LES model with Reynolds range from 500 to 5000. the boundary condition is full periodic condition.
But in the laminar-turbulent transition zone (Re 1500-2000), it take long time to reach the turbulent status. Then i want to add a noise in the flow to have earlier turbulence to save the CPU time.
Does anyone give me some advice?
Here is the GradP of Re1500 and Re5000.goo.gl/Gihp8O
Many thanks

[FMDenaro]

Originally Posted by bienxanh1901

Hi everyone, I am running Echangeur geometry with LES model with Reynolds range from 500 to 5000. the boundary condition is full periodic condition.
But in the laminar-turbulent transition zone (Re 1500-2000), it take long time to reach the turbulent status. Then i want to add a noise in the flow to have earlier turbulence to save the CPU time.
Does anyone give me some advice?
Here is the GradP of Re1500 and Re5000.goo.gl/Gihp8O
Many thanks

Generally, you can add any type of small perturbation, no matter you set it you must wait enough time such that the solution forget the initial state ...
SOme example of forcing some specific wavenumber is in:

http://journals.cambridge.org/action...ine&aid=394792