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-   -   Transient heat transfer simulation with variable heat source (https://www.cfd-online.com/Forums/cfx/112760-transient-heat-transfer-simulation-variable-heat-source.html)

 rdr February 4, 2013 21:57

Transient heat transfer simulation with variable heat source

Hi,

I am relatively new to CFX and am trying to simulate the transfer of heat from an electrical component to its surrounding fluid and enclosure.

The component has a duty cycle and hence its power output is a dependent on time.

What is the best way to simulate the fluctuating power output of the component?

Thanks

 Jeremy B. February 5, 2013 08:38

Hi,
It should be possible to use CEL expressions to simulate this fluctuation.

Depending on the informations you have and on what you are modeling, you can use an expression to:
1) Directly control the heat generation of your system.
Or
2) Control the intensity of the current in your system
(you will probably also need to define an other expression if you want a temperature dependant electrical resistance)

I hope I understood your problem.

Edit:
"Time" or "t" are the variable "current time" in seconds in a transient simulation.
"T" is the temperature if you need a temperature dependant electrical resistance.

 ghorrocks February 5, 2013 18:18

You can either:
* Work out the average power output and do a steady state simulation. This is a simplification but is much quicker and easier.
* Model the transient on/off behaviour and run the transient until it reaches a periodic steady state. This will be a much longer simulation.

 mariconeagles96 July 31, 2015 04:33

Quote:
 Originally Posted by rdr (Post 406020) Hi, I am relatively new to CFX and am trying to simulate the transfer of heat from an electrical component to its surrounding fluid and enclosure. The component has a duty cycle and hence its power output is a dependent on time. What is the best way to simulate the fluctuating power output of the component? Thanks
Hi! Im interested in your simulation. Did u happen to solve this one? Wanted to compare my simulation to yours. Thanks! =)

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