loss coefficient

wilson · December 16, 2009, 13:40

I performed a laminar flow computation on a turbulent flow and found a loss coefficient of 3.54. Using the k-e model, the loss coefficient was 3.80. Why are these different? I think it is something to do with the dissipation of energy but I am looking for a better explanation.

Thanks

ghorrocks · December 16, 2009, 16:46

There are many reasons why if you magically make a flow laminar it could have lower loss coefficients. The main reason is probably due to the much reduced shear stress in the boundary layer leading to reduced drag, but there could be other reasons. For more information see a turbulence textbook.

December 16, 2009, 13:40	loss coefficient	#1
wilson New Member Mike Join Date: Dec 2009 Posts: 14 Rep Power: 16	I performed a laminar flow computation on a turbulent flow and found a loss coefficient of 3.54. Using the k-e model, the loss coefficient was 3.80. Why are these different? I think it is something to do with the dissipation of energy but I am looking for a better explanation. Thanks

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December 16, 2009, 16:46		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,700 Rep Power: 143	There are many reasons why if you magically make a flow laminar it could have lower loss coefficients. The main reason is probably due to the much reduced shear stress in the boundary layer leading to reduced drag, but there could be other reasons. For more information see a turbulence textbook.