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Square Geometry with Turbulent Flow and Fixed Temperature Walls Help
Posted 25.06.2013, 16:45 GMT-4 1 Reply
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Hello,
I am trying to model a square geometry with air inside and the walls at fixed temperatures. The model I chose was this:
Conjugate Heat Transfer --> Turbulent Flow --> k-e model using stationary.
I built the square easily enough.
For Materials, I choose air at an average of 50C. From there, I took the properties I needed:
Thermal conductivity, density, Cp, dynamic viscosity, and ratio of specific heats.
I applied boundary conditions to the square for the temperature. I made the top and bottom insulated. The right side of the box is at 0C and the left side is at 100C. These are boundary conditions.
My question is this: I made a normal mesh and tried running it but it just doesnt go anywhere. The mesh only has 3000 element and 12,000 dof's. I have done more on my computer so I know it can handle it.
Do I need to apply some sort of conditions for the turbulent part?
I'm just trying to get the walls to heat the flow and look at the fluids movement.
Thanks,
David
I am trying to model a square geometry with air inside and the walls at fixed temperatures. The model I chose was this:
Conjugate Heat Transfer --> Turbulent Flow --> k-e model using stationary.
I built the square easily enough.
For Materials, I choose air at an average of 50C. From there, I took the properties I needed:
Thermal conductivity, density, Cp, dynamic viscosity, and ratio of specific heats.
I applied boundary conditions to the square for the temperature. I made the top and bottom insulated. The right side of the box is at 0C and the left side is at 100C. These are boundary conditions.
My question is this: I made a normal mesh and tried running it but it just doesnt go anywhere. The mesh only has 3000 element and 12,000 dof's. I have done more on my computer so I know it can handle it.
Do I need to apply some sort of conditions for the turbulent part?
I'm just trying to get the walls to heat the flow and look at the fluids movement.
Thanks,
David
1 Reply Last Post 25.06.2013, 17:04 GMT-4
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Posted:
1 decade ago
Yes, turbulent flow normally requires a fairly detailed mesh.
As a guide, and perhaps even you final mesh, try allowing COMSOL to create the initial mesh for you. You can do this by selecting "physics" generated instead of "user" defined mesh. It will end up a free mesh everywhere, overlayed with a boundary layer mesh for the walls you have defined to be turbulent walls. You can then try to solve this, followed by similarly defined user mesh and resolved.
As a guide, and perhaps even you final mesh, try allowing COMSOL to create the initial mesh for you. You can do this by selecting "physics" generated instead of "user" defined mesh. It will end up a free mesh everywhere, overlayed with a boundary layer mesh for the walls you have defined to be turbulent walls. You can then try to solve this, followed by similarly defined user mesh and resolved.