Simulating a separation bubble on a blade

j-blindi · August 18, 2012, 07:56

Hello,

I am simulating a blade with Re=210,000 and a turbulence about 2%. According to experimental data, a separation bubble should occur at about half of the blade chord but in my simulation I only get a big separation.
I am using SST for turbulence and my y+ is less than 1 (except for the leading edge).
I already run a many simulation on that case, but I don't even come close to a separation bubble.

Do you have any suggestions what could influence the bubble?

Thanks a lot.
Regards
Jason

PS: I'm not very experienced in CFD yet.

ghorrocks · August 19, 2012, 19:17

Is the separation you are looking for a laminar separation bubble? You will need the turbulence transition model to capture this.

In the Re range you quote it is quite possible it is a laminar separation bubble.

August 18, 2012, 07:56	Simulating a separation bubble on a blade	#1
j-blindi New Member Jason Join Date: Aug 2011 Posts: 10 Rep Power: 14	Hello, I am simulating a blade with Re=210,000 and a turbulence about 2%. According to experimental data, a separation bubble should occur at about half of the blade chord but in my simulation I only get a big separation. I am using SST for turbulence and my y+ is less than 1 (except for the leading edge). I already run a many simulation on that case, but I don't even come close to a separation bubble. Do you have any suggestions what could influence the bubble? Thanks a lot. Regards Jason PS: I'm not very experienced in CFD yet.

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August 19, 2012, 19:17		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,703 Rep Power: 143	Is the separation you are looking for a laminar separation bubble? You will need the turbulence transition model to capture this. In the Re range you quote it is quite possible it is a laminar separation bubble.