k-e
 

in turbulence case alwayse how do you descide the value of k an e?

Re: k-e
 

On velocity inlets

k=1.5*(turbulence intensity * velocity)^2

and in general

ep=cmu^.75 * k^1.5 / length scale

cmu = 0.09 usually

length scale can be 10% of a characteristic dimension

Re: k-e
 

thanks,but... how is the turbulence intensity ?

Re: k-e
 

turbulence intensity is defined as the fluctuating velocity component divided by the nominal velocity, typically 10% is a combustor 1%-6% in a wind tunnel. Have a look at the values they use in the tutorials or the user guide