Transition over airfoil using k-kl-omega model

Spark117 · July 16, 2019, 10:20

Hi !

For my project I'm supposed to study the flow transition from laminar to turbulent around an aerofoil of a racing car.

I've done several analysis using the k-kl-omega model on FLUENT and the thing is, I don't know which variable is the most accurate to say where the transition occurs on the aerofoil...

Should I use the Cp plot, the turbulent viscosity plot, the specific dissipation rate (omega) plot or the turbulent kinetic energy plot ?

And also, is the eddy viscosity contour good to get an idea of where the transition occurs ?

Thank you for your help.

Antoine

PS: I have attached some of the plot and contour I did for a k-kl-omega analysis using a 8deg angle of an Eppler-387 aerofoil.

LuckyTran · July 16, 2019, 11:12

Isn't there an intermittency factor which tells you whether the flow is laminar or turbulent, with values between 0 and 1 representing the transition region?

transition isn't a binary trait, it is a phenomenon. Each of these variables can be used to define a transition (each in a different kind of sense).

Spark117 · July 17, 2019, 05:21

Thank you for your answer !

Well, I have actually heard about this intermittency factor on Fluent but I haven't been able to make it work...

Do you know how to set it up ?

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July 16, 2019, 11:12		#2
LuckyTran Senior Member Lucky Join Date: Apr 2011 Location: Orlando, FL USA Posts: 5,751 Rep Power: 66	Isn't there an intermittency factor which tells you whether the flow is laminar or turbulent, with values between 0 and 1 representing the transition region? transition isn't a binary trait, it is a phenomenon. Each of these variables can be used to define a transition (each in a different kind of sense).

July 17, 2019, 05:21		#3
Spark117 New Member Antoine Join Date: Jul 2019 Posts: 2 Rep Power: 0	Thank you for your answer ! Well, I have actually heard about this intermittency factor on Fluent but I haven't been able to make it work... Do you know how to set it up ?