Difference in lift, inviscid comp. to viscid
 

Dear all,

I am simulating 2D-airfoils in a subsonic flow. Relevant for me is the total lift (force in y-direction). The strongly differing results from inviscid calculations compared to k-epsilon calculations (10 to 20% depending on the airfoil and angle of incidence) surprised me. I would expect some increase in pressure due to drag but not this much.

Do any of you have experienced the same and maybe know a percentage figure of the difference that is to be expected? Are there more reasons for this difference?

Thank you in advance for your help

Greetings Stephan

Re: Difference in lift, inviscid comp. to viscid
 

Dear Stephan,

Are you comparing two different turbulence models?

Opaque

Re: Difference in lift, inviscid comp. to viscid
 

Dear Opaque,

thanks for answering. The purpose of my simulations is to find out whether I can use the inviscid (Euler-) solver to get the lift distribution without a major error or how big this error would be. The only turbulence model I used so far to compare the inviscid results to was the k-epsilon (realizable) model.

Greetings Stephan