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Time step in Transient simulation

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Old   February 2, 2011, 17:31
Default Time step in Transient simulation
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how should we calculate time step in case of transient simulations ? I am simulating slurry flow (water and sand) in pipes ? Has anyone done simulation of slurry flow ? Had some queries ? Thnx.
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Old   February 2, 2011, 21:56
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In transient simulations, the time step is set, not calculated. A rule of thumb is that if your transient simulations are converging in 5-7 time steps (after the initial few, which may take slightly more), your time step is small enough.

Two phase (solid-liquid, solid-vapor) transport of granular solids can definitely be modeled in Fluent. The appropriate drag law is important, as is the characterization of the type (mono-disperse, poly-disperse) of particles you're flowing.

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Old   February 3, 2011, 00:55
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Thanks for the reply. I am trying to simulate water sand slurry using Eulerian and Mixture model. Do we have to patch the initial sand fraction before iterating ? I am trying both the models.
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