|May 18, 2015, 18:16||
Too small time step?
Join Date: Nov 2011
Posts: 4Rep Power: 6
I'm calculating heat transfer from hot air flow to a thin metal wire. Model is transient, and what I'm trying to find is a temperature response (step response) of mentioned wire.
In theory I should get something like this:
Model is defined quite precisely, but results are strongly depenent on time step size.
Air flow speed is constant almost everywhere and equal to 5m/s.
The smallest cell has size of 0.001mm. It is so small because metal wire is 0.01mm in diameter.
According to this data I set up the time step to 2e-7s, but results were completly ridiculous. I have prepared comparison of solutions with different time step sizes. It seems that solution which is the closest to experimental data is for time step much bigger than 2e-7s.
Could you tell me why it is so, and how should I find the proper time step?
Thank you for any of your help
|time step size|
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