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 sunilpatil March 12, 2013 09:00

Wall Heat Transfer Coefficient

Hello sir,
I want to write CEL Expression for wall heat transfer Coefficient to calculate
wall heat flux (Q) but in my problem wall is at middle of an encloser i want to calculate Q for both sides of wall how to specify particular surface to calculate
Wall Heat Flux (Q) in CFX.
Thank you sir.

 JuPa March 12, 2013 09:46

If you're going to deduct wall heat transfer coefficient then I believe (one of the more experienced CFD engineers can correct me on this) you must have adequate refinement at the wall in order to resolve the thermal boundary layer, which is usually smaller than a viscous boundary layer!

 sunilpatil March 12, 2013 11:17

Wall Heat Transfer Coefficient

Hello Sir,
i want to calculate heat transfer coefficient at wall side 1 and side 2 and also heat transfer rate if we subject wall for different temperature conditions or varying Temperature
Thank you sir.

 JuPa March 12, 2013 12:45

Hi,

1. What your boundary conditions are.
2. Working fluid (water, air, or other).

It looks like a simple problem but without more thorough information I can't be of any help.

 ghorrocks March 12, 2013 18:18

Are you simulating this as a conjugate heat transfer simulation? That is, including heat transfer in the wall?

 sunilpatil March 13, 2013 07:44

Wall Heat Transfer Coefficient

Hello sir,
i am simulating this as a conjugate heat transfer problem
Boundary conditions are
1.Varying Temperature With Time To middle Wall
2.Material Working Medium-air at 25 C , Wall = Copper
Thank You

 ghorrocks March 13, 2013 17:29

What do you mean by "varying temperature with time to middle wall".

 sunilpatil March 14, 2013 01:24

Varying Wall Temperature

Hello sir,
I am applying This(http://s23.postimage.org/plc9nhfcb/cfd.jpg) type boundary
condition to Middle Wall

In that
x-axis Time in Seconds
Y-axis Temperature in Kelvin
(all this for transient case)
Thank you sir

 ghorrocks March 14, 2013 06:28

If you already know the temperature of the middle wall then why are you simulating the middle wall as a CHT solid? Just impose your temperature function as a temperature boundary and nothing else is required.

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