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CFX Transient time step

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Old   September 11, 2007, 13:23
Default CFX Transient time step
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I need a advice for select a time step for a simulation in a centrifugal pump.Where i begin? What i have that consider for this?


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Old   September 11, 2007, 16:20
Default Re: CFX Transient time step
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To start, try a timestep that is at least 1/20th of the time it takes for one blade passage. The following expressions will return the appropriate time for a rotor with 11 blades at 30,000 RPM with 20 steps per passage

RPM = 30000 [rev/min] Number of Passages = 11 steps per passage = 20 timeStep = 1/RPM/Number of Passages/steps per passage or timeStep = 1/(RPM*Number of Passages*steps per passage)

You can then use 'timeStep' to specify the timestep instead of inserting a value, allowing you to change 'steps per passage' as desired.


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