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Best Turbulence Model for Heat Transfer in Jet Impingement

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Old   July 21, 2014, 16:57
Default Best Turbulence Model for Heat Transfer in Jet Impingement
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ara
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Hi,

I am using STAR CCM+ for modeling Heat Transfer in jet impingement arrangement (I have a jet plane and a target plane). My current model is v2f. As it is written in STAR CCM+ tutorial, this model is good for heat transfer but it seems that it is suitable for low Re numbers (nothing mentioned about what Re should be based on).
In my case, Re number based on first row jet diameter is 125000 which is definitely not low Re regime.

1- Can I use this model for my case?

2- Is it possible to copy a "scene" in one simulation and paste it in another simulation?

Thanks
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Old   July 21, 2014, 20:27
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That's not what is meant by low Re. In reference to a turbulence model, low Re means that particular model resolves the viscous sublayer. Be sure to have a mesh that has a y+ of 1 or lower.

Yes, you can copy scenes from one sim to another. Just open both sims in the same client and move the trees side-by-side.
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Old   July 24, 2014, 19:00
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Thanks for your reply.
I have another question about creating user field function. I want to split one of my boundaries using "Split by Function". The area I want to split is between certain points (-0.142875<=y<=0.142875) and . I use:

($$)Position[2] <= 0.142875)? 1($$Position[2] >= -0.142875)? 2:0)

It does not work and I do not have any idea of what [2] means.
Any help would be appreciated.
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Old   July 24, 2014, 22:46
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$$function indicates a vector quantity. If you want to utilize a certain component of a vector quantity, you need to say $$function[i], where i is 0, 1, or 2, corresponding to i,j,k.

For your function, you could say:

($$Position[1]<=0.142875&&$$Position[1]>=-0.142875)?1:0

Which in english reads:
If position in y is less than or equal to N and position in y is greater than or equal to M then return 1 else 0.
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Old   July 25, 2014, 11:48
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Quote:
Originally Posted by me3840 View Post
$$function indicates a vector quantity. If you want to utilize a certain component of a vector quantity, you need to say $$function[i], where i is 0, 1, or 2, corresponding to i,j,k.

For your function, you could say:

($$Position[1]<=0.142875&&$$Position[1]>=-0.142875)?1:0

Which in english reads:
If position in y is less than or equal to N and position in y is greater than or equal to M then return 1 else 0.
Thanks for your reply. After I use the above command and select position and length as dimension in user defined function, I choose this function in "Split by Function" for the target boundary and select coordinate system(local), But it gave below warning:

The definition for vector function User Defined Field Function 1(User FieldFunction_1) is not a vector value.

Have you faced with this warning before?

Many Thanks
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Old   July 25, 2014, 12:45
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Quote:
Originally Posted by ara View Post
Thanks for your reply. After I use the above command and select position and length as dimension in user defined function, I choose this function in "Split by Function" for the target boundary and select coordinate system(local), But it gave below warning:

The definition for vector function User Defined Field Function 1(User FieldFunction_1) is not a vector value.

Have you faced with this warning before?

Many Thanks
I changed position to scalar and I was able to split the boundary.
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