Yplus in CFX
Dear Sir,
I was really confused in CFX Yplus. I can check the value of Yplus in CFX-post, but which is good? Yplus>11 or Yplus<11 Thank you in advance. Best Regards Eric |
Re: Yplus in CFX
Refer to Guidelines for Mesh Generation in CFX Help. Basically, Yplus>20 (<200) for wall function. Yplus<2 for low-Re model.
BB |
Re: Yplus in CFX
Hi,
Or use the automatic wall functions approach and let the solver take care of it, then you only have to worry about mesh independance. Glenn Horrocks |
Re: Yplus in CFX
Thank you very much for the kind reply
My simulation is compressible in a pipe. So, If 20 < Yplus <200, the resulte is acceptable. Is it right? Thank you in advance. Eric |
Re: Yplus in CFX
It depends. You still need to validate & verify your solution. You should treat Y+ value as an indicator to minimise the numerical error, not to judge the accuracy of your solution.
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Re: Yplus in CFX
Also you should ideally have 10 nodes or so in the BL.
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Re: Yplus in CFX
Hi, Johnny. This is a general guideline only. You may need a lot more if boundary layer flow is important in your analysis.
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Re: Yplus in CFX
Dear Friends,
Thank you for the reply and the discussion. If y+ plus is not good in my simulation, what can I do? Many thanks Eric |
Re: Yplus in CFX
Make the innermost mesh layer thinner. Y+ is directly proportional to the cell height.
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Re: Yplus in CFX
You have to limit the growth rate between adjacent layers as well.... I usually set it around 1.1~1.3
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renolds number-flow type
hi all,
This is naveen.i am working with the cfx 10,where i am analysing air flow past a circular cylinder.and my reynolds number is 7e+4.i would like to know for such kind of reynolds number ,which fluid flow ( transition flow or turbulence flow ) will influence more on my problem and why? how can i know exact critical reynolds number(transition point) for my case. i want to hear from you, thanks all regards, Naveen |
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