Bad Cd results applying k-ε models to hydrofoil

spk · December 9, 2011, 05:17

Hi guys,

I simulated a 2D hydrofoil geometry in non-cavitating conditions.
The tested angles are from 0 to 10 degrees and the velocity is constant.
I simulated this hydrofoil using Spalart-Allmaras, k-ε models and k-ω models. Using S-A and k-ω models i have good results for Cl and Cd comparing with experimental results.
But using the k-ε models (standard,rng,realizable) i have good results for Cl but bad results for Cd (as the angle attack increases Cd decreases!)
Also i used enhanced wall treatment (y+=1).

k-ε models cant solve correctly the drag coefficient in hydrofoils?
Please could you help me?

spk

spk · December 10, 2011, 08:27

The problem is solved!

December 9, 2011, 05:17	Bad Cd results applying k-ε models to hydrofoil	#1
spk Member Join Date: Aug 2009 Posts: 67 Rep Power: 16	Hi guys, I simulated a 2D hydrofoil geometry in non-cavitating conditions. The tested angles are from 0 to 10 degrees and the velocity is constant. I simulated this hydrofoil using Spalart-Allmaras, k-ε models and k-ω models. Using S-A and k-ω models i have good results for Cl and Cd comparing with experimental results. But using the k-ε models (standard,rng,realizable) i have good results for Cl but bad results for Cd (as the angle attack increases Cd decreases!) Also i used enhanced wall treatment (y+=1). k-ε models cant solve correctly the drag coefficient in hydrofoils? Please could you help me? spk

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December 10, 2011, 08:27		#2
spk Member Join Date: Aug 2009 Posts: 67 Rep Power: 16	The problem is solved!