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Heat transfer in actively-cooled composite

Posted Nov 20, 2024, 8:27 a.m. EST Fluid & Heat, Heat Transfer, Results & Visualization 0 Replies

Toby Wilcox

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I have set up a heat transfer in solids and fluids model to mimic an experiment and I am having trouble getting accurate temperature results.

In my experiment, I have a composite sample with three hollow channels embedded within it. I heat the bottom surface of the sample with a heater mat which is controlled by power input. I then actively cool the sample by pumping water through the channels. I capture the before and after surface temperatures using an IR camera.

My model has been set up in the same way. I have a boundary heat source at the sample/heater mat interface and surface-to-ambient radiation on all other surfaces. In the flow case (10-30ml/min) I have maximum and average temperatures in good agreement with my experimental results at the same heating rate (within 10%). However, in the no-flow case, the temperature in my model is 240% higher than my experiment (exp ~ 50 degrees at 3W; model ~ 120 degrees at 3W). Does anyone know the reason for this large discrepancy?

I have tried changing the heat source from domain to boundary and from heat rate to heat flux. I have also tried modelling open surfaces as external free convection or with convection coefficient instead of surface-to-ambient radiation. Whatever I try seems to give a similarly high spike in the results.

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3 Channel.mph

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