Conjugate heat transfer problem with Temperature dependent property

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  • Last Post 17 December 2018
ashiadarsh posted this 17 December 2018

I was trying to simulate a conjugate heat transfer problem where the working fluid is water.Physical properties like specific heat,viscosity and thermal conductivity was approximated as a polynomial function of temperature(say third degree polynomial),data taken from NIST

In addition to that if i am giving density also as polynomial function of temperature divergence is detected in the solver-ANSYS FLUENT.How can i overcome this issue?

Actually in my problem over the temp. ranges encountered density varies.

Adarsh

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ashiadarsh posted this 17 December 2018

Ok i will try to simulate the problem with gravity on and will get back...thank you for the reply

rwoolhou posted this 17 December 2018

You need to switch gravity on whenever there is a density difference in the fluid. If the flow is pressure driven, is there enough of a density difference to need to include the effect? Are you sure there isn't natural convection too? 

ashiadarsh posted this 17 December 2018

I have a solid domain and a fluid domain...i didnot turn gravity on...i would like to know in what type of problems do we need to turn on the gravity?is it for natural convection problems only?...in my case the flow is driven by the pressure difference...i will get back to you with pictures added...thank you for the reply

Adarsh

rwoolhou posted this 17 December 2018

Start by checking the mesh and that the polynomials are giving sensible values over the range you're modelling. I assume you have flow boundaries and have turned on gravity? 

Pictures will help, and please add these into the text as staff can't open attachments. 

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