Transport properties

mukundsunil · June 12, 2020, 09:42

I'm simulating an external flow over an airfoil. When I try to change the value of kinematic viscosity in transport properties file for any turbulent model, be it spallart allmarus or k-omega SST, the result will remain the same as that of the original case file. How can I change this?
Regards
Mukund S

Ardali · June 12, 2020, 11:40

What do you mean exactly?
You change a value and the result remain the same. The flow over an airfoil is very abstract. What is angle of attack, what is Re number, which airfoil are you studying?
In general the flow over an airfoil in not that sensitive to small change of nu.
If you have separation and reattachment that is difficult issue which SA or SST have problem in capturing. Anyway, small change of nu does not change anything. In practice, you increase your Re in turbulent region. So what do you expect?

Ardalan

dlahaye · June 15, 2020, 02:22

turbulence model settings in constant/turbulenceProperties
transport properties in constant/transportProperties

June 12, 2020, 09:42	Transport properties	#1
mukundsunil New Member mukund Join Date: Mar 2020 Posts: 3 Rep Power: 6	I'm simulating an external flow over an airfoil. When I try to change the value of kinematic viscosity in transport properties file for any turbulent model, be it spallart allmarus or k-omega SST, the result will remain the same as that of the original case file. How can I change this? Regards Mukund S

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June 12, 2020, 11:40		#2
Ardali Member Ardalan Join Date: Jul 2012 Location: Atlanta, USA Posts: 77 Rep Power: 13	What do you mean exactly? You change a value and the result remain the same. The flow over an airfoil is very abstract. What is angle of attack, what is Re number, which airfoil are you studying? In general the flow over an airfoil in not that sensitive to small change of nu. If you have separation and reattachment that is difficult issue which SA or SST have problem in capturing. Anyway, small change of nu does not change anything. In practice, you increase your Re in turbulent region. So what do you expect? Ardalan

June 15, 2020, 02:22		#3
dlahaye Senior Member Domenico Lahaye Join Date: Dec 2013 Posts: 722 Blog Entries: 1 Rep Power: 17	turbulence model settings in constant/turbulenceProperties transport properties in constant/transportProperties