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How to use a step function in a time-dependent study?
Posted 23 mar 2020, 15:48 GMT-4 Fluid & Heat, Interfacing, Parameters, Variables, & Functions 1 Reply
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Hello everyone! Thank you so much for your precious time.
I have a time-dependent study that runs for 400 seconds. I am simulating flow through a pipe, and I want to change the flow at 100 seconds. For example, the inlet flow is A from 0 seconds to 100 seconds. Then, the inlet flow changes to B at 100 seconds, and stays like this until the end of the simulation.
Could someone explain the meaning of the step function's inputs (location, from, to)?
Thank you!
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Hi,
The step function should then be set up with Location set to 100 (the switch time), From set to A, and To set to B. When you use the step function in the simulation, call it like step1(t[1/s]) (if the step function name is step1). Use the Plot button at the top of the settings for the Step function node to plot the step function and check that it behaves as intended. Also, see the cylinder_flow model in the COMSOL Multiphysics Application Library for an example that uses a step function in an inlet condition.
Best regards,
Magnus Ringh, COMSOL