Changing Wall Heat Flux in CFX-Pre Doesn't Change Wall Heat Transfer Coef in CFD-Post

Nourhan Bahgat · October 15, 2019, 09:06

Thanks alot for your help,
these are Mesh file and output file
https://drive.google.com/file/d/1667...?usp=drive_web

ghorrocks · October 15, 2019, 19:16

Please post images directly on the forum, not on third party websites. I cannot view the google drive link you sent as you did not make it viewable (but don't bother fixing it, just post them directly on the forum).

I note that this has a solid and a fluid domain. Make sure the images show these domains clearly.

Nourhan Bahgat · October 15, 2019, 20:01

Sorry, I have a trouble in uploading this file directly to the forum, now you can access the file on google drive.
Sorry again, I forgot to let the sharing on

ghorrocks · October 16, 2019, 18:38

How many elements do you have in the length (z) direction? Isn't the image just interpolating between your very coarse mesh in the z direction?

Nourhan Bahgat · October 16, 2019, 18:44

Quote:

Originally Posted by ghorrocks

How many elements do you have in the length (z) direction? Isn't the image just interpolating between your very coarse mesh in the z direction?

About 200 element over length 7.8 m

ghorrocks · October 16, 2019, 18:53

Let me clarify my comment: You have inlet and outlet boundaries at either end of the domain. I am not sure how exactly how the heat transfer at the boundaries is calculated and it is likely that the different conditions applied at the boundary condition mean the wall heat transfer is modified. Then combine this with your very coarse mesh in the z direction and you get the different boundary condition values smeared a long way along the domain.

Nourhan Bahgat · October 16, 2019, 18:59

Quote:

Originally Posted by ghorrocks

Let me clarify my comment: You have inlet and outlet boundaries at either end of the domain. I am not sure how exactly how the heat transfer at the boundaries is calculated and it is likely that the different conditions applied at the boundary condition mean the wall heat transfer is modified. Then combine this with your very coarse mesh in the z direction and you get the different boundary condition values smeared a long way along the domain.

Ok, I understand what you say and will modify the mesh element in z direction ...thanks alot for you 🙏🙏

October 15, 2019, 19:16		#22
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,852 Rep Power: 144	Please post images directly on the forum, not on third party websites. I cannot view the google drive link you sent as you did not make it viewable (but don't bother fixing it, just post them directly on the forum). I note that this has a solid and a fluid domain. Make sure the images show these domains clearly. __________________ Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.

October 16, 2019, 18:38		#24
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,852 Rep Power: 144	How many elements do you have in the length (z) direction? Isn't the image just interpolating between your very coarse mesh in the z direction? __________________ Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.

October 16, 2019, 18:53		#26
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,852 Rep Power: 144	Let me clarify my comment: You have inlet and outlet boundaries at either end of the domain. I am not sure how exactly how the heat transfer at the boundaries is calculated and it is likely that the different conditions applied at the boundary condition mean the wall heat transfer is modified. Then combine this with your very coarse mesh in the z direction and you get the different boundary condition values smeared a long way along the domain. __________________ Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.

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