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carno May 28, 2004 00:09

-ve pressure
 
Hi All

I am doing one simple simulation involving pressure calculations. But my problem is that I am getting -ve abs pressures at zones where there are high velocities (region of small gap).

I have tried refining the mesh. (all tets). But still I fail to get good solution. Kindly guide. Fluid is water. Pressure difference at inlet and outlet is 60psi(~4bar).

What shall I do?

thanks

Jörn Beilke May 28, 2004 04:28

Re: -ve pressure
 
Are you sure that your flow is non-cavitating in the reality?

carno May 28, 2004 08:27

Re: -ve pressure
 
Thanks Jörn

Right now I have no idea, but I have restarted the run with reduced pressure differential. This is working fine. Slowly I will ramp the pressure to my desired value. Lets see. Velocities go around 24m/s for water in 0.25mm gap. (where I get -ve pressure)

Anyway, if the flow is cavitating, what is the option? Shall I solve it with cavitation model?



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