initialising a thermal boundary layer

yamifm0f · October 22, 2018, 08:10

I want to initialise a thermal boundary layer with a temperature profile but I do not know how.
I have been looking at the Prescribing Constant Temperature in Fluid Cells but it is not clear to me. I have tried it for a fluid only domain. To use Prescribing Constant Temperature in Fluid Cells I need to have a volumetric heat source, which I do not have.
Is there any other way to initialise the thermal boundary layer?

me3840 · October 22, 2018, 17:54

If you want to do this as a field and your flow is turbulent it would be very easy to assign a field function with the layer profile using the wall distance field function as the position in your profile.

yamifm0f · October 24, 2018, 10:26

Quote:

Originally Posted by me3840

If you want to do this as a field and your flow is turbulent it would be very easy to assign a field function with the layer profile using the wall distance field function as the position in your profile.

thanks for your reply

I am using a laminar flow model with no velocity inlet, just two pressure outlets.

can you explain a bit more on how to implement it.

me3840 · October 29, 2018, 18:09

You would have to turn on a turbulence model first. Then create a field function with your desired boundary layer profile, using the wall distance field function as the independent variable. Initialize the simulation, then switch the physics from turbulent to laminar, and then run.

I haven't tried doing that before, so it might break, but you'll have to see.

October 22, 2018, 08:10	initialising a thermal boundary layer	#1
yamifm0f Member fa Join Date: Nov 2013 Posts: 30 Rep Power: 12	I want to initialise a thermal boundary layer with a temperature profile but I do not know how. I have been looking at the Prescribing Constant Temperature in Fluid Cells but it is not clear to me. I have tried it for a fluid only domain. To use Prescribing Constant Temperature in Fluid Cells I need to have a volumetric heat source, which I do not have. Is there any other way to initialise the thermal boundary layer?

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
CFD analaysis of Pelton turbine	amodpanthee	CFX	31	April 19, 2018 18:02
GETVAR Error in Multiband Monte Carlo Radiation Simulation with Directional Source	silvan	CFX	3	June 16, 2014 09:49
Error finding variable "THERMX"	sunilpatil	CFX	8	April 26, 2013 07:00
Convective Heat Transfer - Heat Exchanger	Mark	CFX	6	November 15, 2004 15:55
errors	Fahad	Main CFD Forum	0	March 23, 2004 13:20

October 22, 2018, 17:54		#2
me3840 Senior Member Join Date: Nov 2010 Location: USA Posts: 1,232 Rep Power: 24	If you want to do this as a field and your flow is turbulent it would be very easy to assign a field function with the layer profile using the wall distance field function as the position in your profile.

October 29, 2018, 18:09		#4
me3840 Senior Member Join Date: Nov 2010 Location: USA Posts: 1,232 Rep Power: 24	You would have to turn on a turbulence model first. Then create a field function with your desired boundary layer profile, using the wall distance field function as the independent variable. Initialize the simulation, then switch the physics from turbulent to laminar, and then run. I haven't tried doing that before, so it might break, but you'll have to see.