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having trouble implementing airfoil with Wall Slip condition

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Old   December 22, 2014, 00:02
Post having trouble implementing airfoil with Wall Slip condition
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Mohammad Hossein Khozaei
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Hello every body

I need to solve my problem on airfoil with wall Slip condition.
as i found, i can put this condition in 2 ways:
1. enter a wall velocity
2. enter specified shear on the wall

In both the ways i need to enter velocity or specified shear with 2 components (x & y).
The problem is, as the normal-vector of the wall is changing around the airfoil and the wall-velocity (and specified shear) are both tangential to the wall, I need to have a local-coordinate-system in each point of the airfoil-wall to enter the velocity due to the local-coordinate-systems. (or something like this)
(I don't have the Airfoil-wall-equation)
(I have to check the results in different slip lengths, 10% slip to 50%, not 100% or free slip)
(and then it must be solved in a complicated 3-D geometry, so i can't split the wall into some semi-linear parts.)

I don't know how to do this and whether it works or not.
can any body help me ? please.
I really appreciate it.


PS.
In easy words, 10% slip means velocity on the wall is 10% of free-stream (tangential to the wall) (wall-slip-condition can be defined by 3 (related) parameters: 1. specified shear 2. wall-velocity 3. slip length, the definitions are available in literature, but in CFX and Fluent i just can enter specified shear or wall velocity, you can find them in wall-boundary-detail) (to avoid mathematical equation it's better to define a wall velocity than specified shear)

Last edited by Khozaei4000; December 22, 2014 at 00:57. Reason: Make it more complete.
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Old   December 22, 2014, 12:30
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Gonzalo
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Mmm, in the case you want specify the velocity on each point of your airfoil, I don't think that is phisically posible. Imagine that situation where each point of the airfoil has a specific velocity relative to an inertial reference frame, so it wold be impossible for the airfol for not be teared apart in little pieces. In the case of specifying the Wall-shear, I don't think you can do it by the GUI, but you should try to do it by using an UDF, so take a look at the UDF manual of FLUENT and take alook if you can do it. In that case comment it to us
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