# Simlab Transient Heat Transfer Analysis

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Hello,

I am studying the assembly of the brake system to evaluate the temperatures over time, of the system. I have defined inital temperatures, thermal contacts between the assembly and all the relevant heat inputs in the disc brake and the brake pads surfaces.. Now i am stuck in defining the convection loads.. If i use a constant convenction film coefficient the results are fine and admissable, but i open the option Time dependent load, and then i start filling the table points the the time and the amplitude of the load. Does this amplitude acts upon the film coefficient or upon the film temperature. I want it to act on the film coefficient and i decided to use the value 1 on the film coefficient and use the table as a scale factor. The values stoped making sense when i did that. Can anybody help me with that?

I am using Simlab 2019.2

On the image below you can se me using the film coefficient of 5e-6, because my units are W/mm^2.C for the coefficient to give correct values. In the table i used the scale factor compared to the defined value. Does that scale factor acts on the temperature or film coefficient?

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Hi Diogo Ferreira,

Scale factor in convection table is used only for temperature. For film coefficient, it will use the constant value.

Refer the below demo video for Transient heat transfer analysis from SimLab learning center.

Let me know if you need any further help in setting up the analysis.

Thanks & Regards,

Santhoshkumar

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Is there any way to do this scale factor to the coefficient? Because in my case that is changing with the car's speed. The fluid temperature is kept the same.

Best regards,

Diogo

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Time varying convection

Convection coefficients can be specified as time-dependent when a control node (CNTRLND) is specified on CONV card.

The control node must be constrained by an SPCD, which is made time dependent by TLOAD1/TLOAD2. The convection coefficient is multiplied by the value from SPCD of control node.

You could use Hypermesh interface to define this input.

Diogo Ferreira likes this

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