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littlelz March 27, 2009 12:26

grid independence study in transition simulation
i am just wondering what variables are supposed to be compared as we do grid independence study for a transition simulation. i Guess transition location on the body is supposed to be one of them, any other key variables?

many thanks

triple_r March 27, 2009 13:04


Have you thought of an integral variable too? (like shear force on wall or something like that)

And also a very simple question, what kind of flow are you trying to simulate using the transition model? Because you know that the transition model in CFX has been tuned for flat plate problem, or external flows at best.

littlelz March 28, 2009 06:15

acturally, we are checking forces and moments too. but the problem is they are changing little, while the transition location change a lot. so I don't know if the mesh is independent or not.

for your info, we are doing transition simulation for external flow.

many thanks for your reply

triple_r March 28, 2009 11:02

I think as for some variables it is harder to achieve mesh independence than the others, you should at the variables that are very important to you, and the variables that you are looking to take out of the simulation.
If the main point of this simulation is to get transition location, then you need to work more on the mesh, and increase its resolution a lot, but if the only important thing (the outcome that you expect) are the forces, then you have reached mesh independence.

littlelz March 30, 2009 07:16

thanks a lot. i got your point and will try more refine mesh.

all the best

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