heat flux for conjugate heat transfer

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  • Last Post 04 February 2019
pavankonchada123 posted this 02 January 2019

I have 5 layers of solid beneath which PCM is present. I have given heat flux through udf on top surface(550w/m2) but after observing the heat flux out of last layer I am getting very low flux inorder 0.2 W/m2

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pavankonchada123 posted this 02 January 2019

I ve patched the entire 5 layers and pcm with 298.5 K and Supplied heatflux from top layer. PCM solidus and liquidus temp is 298.6 and 300.6 K. Solution method is coupled with pressure, momentum and energy with standard , second order and second order control 

rwoolhou posted this 02 January 2019

Assuming it's a transient model have you run long enough for the wall to heat up and conduction energy into the fluid region? 

pavankonchada123 posted this 03 January 2019

yes 19000 seconds if I remove all 4 layers and keeping the last layer it is working (I mean the temperature of fluid is raising and I am able to see liquid fraction)

5 layers I taken are glass,eva,silicon,eva,tedlar,aluminium and PCM. I have created a part in ansys design modeler, so I got automatically the wall and shadow between 5 layers of different thickness. I have kept material name of adjacent layer material in coupled parameter set up, and hence shadow region also got the same material name ( for example glass has adjacent layer for wall interface I kept material name as glass and automatically for shadow wall with adjacent layer as eva has also got the material name as glass)

abenhadj posted this 03 January 2019

A screenshot of model and boundary specifications in ANSYS FLUENT is mandatory for us to understand. Moreover add some information of the thermal diffusivity as well as the volume of each of you solid zones. 

Best regards,

Amine

pavankonchada123 posted this 04 January 2019

DimensionsProperties

pavankonchada123 posted this 04 January 2019

I have meshed by forming a part for all layers in ansys design modeler. 500 w/m2 flux is given on top of glass surface

pavankonchada123 posted this 04 January 2019

on the outer surface adiabatic is given, with initialization of 298.6 K and patching 298.6K for all layers

pavankonchada123 posted this 07 January 2019

Please do answer me

rwoolhou posted this 07 January 2019

If you've set 500W on the glass and adiabatic everywhere else how does the heat escape? Check you've got a conformal mesh (multibody part) or contact, also please post an image of the temperature field. 

As an aside, the community is covered by a mix of volunteers and ANSYS staff. The latter tend to work Monday-Friday in a range of time zones so please be patient. It's also been the Christmas & New Year holiday period so most have been taking time off. 

abenhadj posted this 07 January 2019

Be patient and provide more screenshots out of Fluent. Add a screenshot of Flux Report 2.

Best regards,

Amine

pavankonchada123 posted this 08 January 2019

yes it is adiabatic I don't want heat to escape out. The heat need to get trapped in the cavity only. I have formed a new part for this geometry along with PCM with shared topology option as automatic

pavankonchada123 posted this 08 January 2019

sorry option I used is default in shared topology

pavankonchada123 posted this 08 January 2019

pavankonchada123 posted this 08 January 2019

rwoolhou posted this 08 January 2019

Sounds right and the mesh looks conformal. Please can you post a contour of temperature. 

pavankonchada123 posted this 09 January 2019

pavankonchada123 posted this 09 January 2019

wall at pcm and aluminium interface

pavankonchada123 posted this 09 January 2019

interface at pcm and aluminium interior, assuming perfect contact between pcm and aluminium

pavankonchada123 posted this 11 January 2019

any update sir, I have given the thickness as zero for surface

abenhadj posted this 11 January 2019

 Please include a Heat flux report here. Please share every single detail of your boundaries as screenshot.

Best regards,

Amine

pavankonchada123 posted this 11 January 2019

pavankonchada123 posted this 11 January 2019

pavankonchada123 posted this 11 January 2019

pavankonchada123 posted this 11 January 2019

pavankonchada123 posted this 11 January 2019

pavankonchada123 posted this 11 January 2019

pavankonchada123 posted this 11 January 2019

pavankonchada123 posted this 11 January 2019

pavankonchada123 posted this 11 January 2019

pavankonchada123 posted this 11 January 2019

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