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having trouble understanding the Flow Direction option in periodic boundary

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Old   March 18, 2016, 14:45
Post having trouble understanding the Flow Direction option in periodic boundary
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Hi
can any one help me on "Flow Direction" option in periodic boundary condition ?
i didn't understand what is it and how set it
thanks
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Old   March 19, 2016, 10:27
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Hi
can any one help me on "Flow Direction" option in periodic boundary condition ?
i didn't understand what is it and how set it
thanks
any help ?
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Old   March 19, 2016, 10:38
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what do you mean by flow direction?
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Old   March 19, 2016, 11:42
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Quote:
Originally Posted by AHF View Post
Hi
can any one help me on "Flow Direction" option in periodic boundary condition ?
i didn't understand what is it and how set it
thanks
I am simulating a turbine and I have Rotational periodic conditions. Here, I think that ""Flow Direction" should be set based on right hand rule.
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Old   March 19, 2016, 12:36
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things are confusing here. You are saying periodic boundary conditions and at the same time you are saying flow direction.!!!!
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Old   March 19, 2016, 12:46
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things are confusing here. You are saying periodic boundary conditions and at the same time you are saying flow direction.!!!!
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Old   March 19, 2016, 12:48
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what type of flow problem you are solving??


It is very much clear. It is direction in which you have pressure gradient. And it has nothing to do with right hand rule... !!!

And are you sure that you need this boundary condition?
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Old   March 19, 2016, 13:15
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Quote:
Originally Posted by Far View Post
what type of flow problem you are solving??


It is very much clear. It is direction in which you have pressure gradient. And it has nothing to do with right hand rule... !!!

And are you sure that you need this boundary condition?
What is your exact meaning of "It is direction in which you have pressure gradient."?

My static pressure contour is as follows:


According to above explanations, how do I set this direction?

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Old   March 19, 2016, 23:20
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do not make any settings for this boundary.
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Old   March 19, 2016, 23:56
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Quote:
Originally Posted by Far View Post
do not make any settings for this boundary.
Why?

Can you explain more about that?

Thanks
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Old   March 20, 2016, 06:01
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these settings for some special problems. They are not for the case you are simulating. So just leave these settings on default...
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Old   March 20, 2016, 11:25
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i will be thankful if any body can help me

this is my problem as seen in the picture attacked

rear and front wall are periodic and also this trapezoidal enclosure is incline. ( gamma angle in picture)
i set rear and front as periodic without any special setting . that is enough ?
or i should change flow direction. please attention that trapezoidal enclosure isn't flat and it is incline

thanks
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Old   March 20, 2016, 11:47
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Quote:
Originally Posted by AHF View Post
i will be thankful if any body can help me

this is my problem as seen in the picture attacked

rear and front wall are periodic and also this trapezoidal enclosure is incline. ( gamma angle in picture)
i set rear and front as periodic without any special setting . that is enough ?
or i should change flow direction. please attention that trapezoidal enclosure isn't flat and it is incline

thanks
Please start a new thread.
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Old   March 20, 2016, 14:22
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Please start a new thread.
i myself create this threat

can you help me
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Old   March 20, 2016, 15:06
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flow direction is used when you have pressure gradient in some direction. for example if you have long pipe and you want to model just a some finite length.


So at inlet and outlet, you just put the periodic conditions and provide direction and pressure gradient. So if pipe length is in x direction then you put direction as 1 0 0
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Old   March 22, 2016, 04:18
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Quote:
Originally Posted by Far View Post
flow direction is used when you have pressure gradient in some direction. for example if you have long pipe and you want to model just a some finite length.


So at inlet and outlet, you just put the periodic conditions and provide direction and pressure gradient. So if pipe length is in x direction then you put direction as 1 0 0
so , if i have periodic condition without pressure gradient , its unnecessary to define flow direction ?
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