Perturbation\Disturbance, Please Guide

Colin

Hi,

In my simulation, I want to add a perturbation to the inlet velocity profile to see its influence on the flow.

I am using a K-E model, I wonder if this perturbation is allowed to be added to the K-E model?

Because K-E model takes the time-average value, I was suggested that the perturbation would be erased off by the model and it is not proper to add a perturbation to a K-E model. Is this true?

Please Guide. Thank you.