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Old   March 25, 2011, 12:45
Unhappy Problem with initial conditions
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Jaskirat
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Hi!
I am new to CFD and am using CFX 12 (Ansys 12).

I am simulating the flow in an intake manifold. The inlet and outlet boundary conditions have been defined by their mass flow rates.
I first ran a steady state simulation with the boundary conditions at t=0.
Using the steady state results file as the initial condition a transient simulation was run. The transient boundary conditions have been defined wrt time using the 'User Function' option.

The problem is that my results are not as expected. During post processing the velocity contour is similar to the initial conditions profile. But the pressure is uniform throughout the geometry (not at all similar to the initial conditions). What could be causing this and how do I correct it?

Thanks!
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Old   March 25, 2011, 13:31
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Kooky
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Can you post the picture?
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Old   March 25, 2011, 13:58
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Jaskirat
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I ran the simulation for 2 timesteps... At the 2nd timestep:
This is the velocity profile...


This is the pressure profile...

The pressure should also depend on the velocity. Why am I getting such results?

Thanks!
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Old   March 26, 2011, 04:42
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Hey! I got it as soon as I posted the picture... The units are wrong (200m!!! :/ )
Thanks!
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