Detached Eddy Simulation

Maged Ismail

Hi all

I am using the Detached Eddy Simulation model for predicting the three-dimensional flow field of a round jet in crossflow. The velocity range is from 15-20 m/s and the domain dimensions are 0.75x0.3x0.3 m. I am using a relatively coarse grid of about 90000 nodes, because the simulation is done on a PC. The unsteady parameters that I have used are:

Time Step Size: 0.0001 No. of Time Steps: 1000 No. of Iterations per Time Step: 20

I have compared the mean results of the DES and results from steady RANS based simulation using standard k-epsilon model against experimental data, and I found that the steady k-epsilon simulation results are slightly in better agreement with the measurements; however both methods highly over-predicted the velocity profiles (with an error of about 250% for the wall-normal velocity).

I would like to know, whether this model (DES) is appropriate for my case and could I get better results by using smaller time step?

Thanks a lot. Maged