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AJ June 21, 2005 11:10

CCM+ Natural convection
 
CCM+ HELP! I'm trying to simulate natural convection from a heated fin into air. The air density and temperature around the fin vary as expected, but there seems to be no air movement. The model is setup with a solid continuum and a fluid continuum. The model for the fluid is as follows: Steady, Laminar, Segegrated Fluid energy, Segegrated flow, Gravity, Ideal Gas, 3D, Static, Gas.

I'm probably missing something simple, but any help would be great. Thanks.

som June 21, 2005 23:34

Re: CCM+ Natural convection
 
check gravity direction and run in double precision

Richard June 22, 2005 03:43

Re: CCM+ Natural convection
 
Wouldn't the temperature field in static air be much different to the one in moving air? So if you're getting the right temperature field, the air must be moving? Maybe it's just a post-processing glitch. Can you see that the velocity magnitude is exactly zero, or are the vector arrows just very short?

AJ June 22, 2005 05:04

Re: CCM+ Natural convection
 
The gravity is on, but not sure how to run the model in double precision in CCM+. Can you tell me? I've checked the postprocessing over and over, both graph plots and scalar/vector displays. Both read no velocity. Thanks guys

Richard June 22, 2005 05:50

Re: CCM+ Natural convection
 
You would need to download a separate double precision version. Have you tried the coupled solver instead of segregated?

AJ June 22, 2005 06:48

Re: CCM+ Natural convection
 
Coupled solver comes up with an error message, telling me: "Error: attempt to access nonexistant TemperatureSource field on cells" Does this mean anything to you?


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