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-   -   Pressure based and Density based Solver (http://www.cfd-online.com/Forums/fluent/112412-pressure-based-density-based-solver.html)

taekyu8 January 28, 2013 12:05

Pressure based and Density based Solver
 
Hi.

I have run transient gas expansion problem. Initially I opened a cap of pressurized vessel.


When I ran with 7 MPa pressure. pressure-based solver does not work, only density-based solver works

However, when I lowered the pressure to 0.5 MPa, pressure-based solver also works.

I know the the pressure-based approach was developed for low-speed incompressible flows, while the density-based approach was mainly used for high-speed compressible flows. However, recently both methods have been extended and reformulated to solve and operate for a wide range of flow conditions beyond their traditional or original intent.

Both 7 MPa case and 0.5 MPa case have chocked flow at the opening. Therefore, I thought if the 0.5 MPa case works with pressure-based solver, the 7 MPa case should works too.

Does anyone explain what cause this problem?

Thanks


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