Fluctuating residuals at high angle of attack for NACA0018

Anand Thamban · June 19, 2016, 03:06

Hello!

I am currently doing an analysis on NACA 0018 to find the stall angle. I have used k-kl-w turbulence model and Re=100,000. After around 18 degrees, the residuals keep fluctuating and so do the Cl values. Even after increasing the AoA, the Cl values fluctuate at a high value and do not seem to drop, like how it is usually supposed to. Can anyone explain the problem with this? I have tried many types of mesh and still encounter the same problem.

Far · June 20, 2016, 08:58

mostly it is related to mesh. second ally you must do transient analysis.

June 19, 2016, 03:06	Fluctuating residuals at high angle of attack for NACA0018	#1
Anand Thamban New Member Anand Thamban Join Date: Jun 2016 Posts: 1 Rep Power: 0	Hello! I am currently doing an analysis on NACA 0018 to find the stall angle. I have used k-kl-w turbulence model and Re=100,000. After around 18 degrees, the residuals keep fluctuating and so do the Cl values. Even after increasing the AoA, the Cl values fluctuate at a high value and do not seem to drop, like how it is usually supposed to. Can anyone explain the problem with this? I have tried many types of mesh and still encounter the same problem.

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June 20, 2016, 08:58		#2
Far Senior Member Sijal Join Date: Mar 2009 Location: Islamabad Posts: 4,558 Blog Entries: 6 Rep Power: 54	mostly it is related to mesh. second ally you must do transient analysis.