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Internal and external natural convection seperation
Posted 9 gen 2013, 18:54 GMT-5 Fluid & Heat, Heat Transfer & Phase Change, Computational Fluid Dynamics (CFD) Version 4.3 0 Replies
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Firstly I would like to say thanks to everyone who so regularly contributes to these forums and breathes life into them; namely Ivar.
I have been setting up a relatively complex (for me) heat transfer problem in COMSOL. The aim is to get to modelling some complex 3D geometry with conduction, internal natural convection in the inside and external natural convection on the outside. The COMSOL forums have been a huge help to me so far so thank you all.
I am trying to model complex 3D geometries with multiple parts interacting together. There are also no symmetry planes that I can use in the part. The computer that I am using is limited to 16GB of RAM which is a very limiting factor for how I go about modelling it in 3D.
What I am trying to do at the moment (in 2D for proof of concept) is separate the internal and external convection and solve them with a segregated solver. I am trying to accomplish this by using two Conjugate Heat Transfer (nitf) physics modules (for want of a better word); one solves the conduction and internal convection, and the other solves the external convection. I am relating these two sets of physics together by making the temperatures at the boundary equal in each module. I am equating the temperatures together by defining the temperature at the boundary at each module. So for nitf I set the temperature as T2 and for nitf2 I set the temperature as T. I can't get the solver to converge in a fully coupled solver and when trying to use a segregated solver [step 1 = u,T,p; step 2 = u2,T2,p2] I get the error:
The following feature has encountered a problem:
Constraint found for variables in different segregated groups. Try to merge these groups.
- Feature: Stationary Solver 1 (sol1/s1)
- Error: Constraint found for variables in different Segregated groups. Try to merge these groups.
I was wondering if anyone has any suggestions of how to get the two calculations working in a segregated solver, or ways in which I could reduce the memory usage.
Please tell me if I need to attach anything, or reword any explanation or describe another aspect.
Thank you all in advance!
Josh
Hello Josh Bate
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