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Old   October 5, 2000, 11:21
Default Mass flow inlet B.C. at exit...
Jack Keays
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HI all,

I am specifying a mass flow rate at the exit in my fluent model. As you can only specify a mass flow rate inlet, I have opted to use the "direction specification method" of a "direction vector" and chossen a -1 value for the x-direction flow. This should give a negative flow. HOwever, upon running the solution, the value of the mass flow rate at both the inlet and outlet become 1.23kg/s in the "report fluxes" menu., whereas it is specified as 25kg/s as the boundary condition. Also, in the "surface integrals" menu, the values for mass flow rate at inlet and exit are 3.24kg/s in, and -1.3kg/s out. The solition is unsteady, and uses a sliding mesh. The values the software is giving are not changing with with time steps. Has anyone any idea what my problem is?? Thank you all.
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Old   October 5, 2000, 13:22
Default Re: Mass flow inlet B.C. at exit...
Pierluigi Allegro
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Why you can only choose mass flow rate? You have: outflow for a incompressible flow and pressure outlet for compressible flow.

Best regards, Pierluigi Allegro
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Old   October 6, 2000, 08:39
Default Re: Mass flow inlet B.C. at exit...
Jack Keays
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I know I can use whichever any Boundary condition, but I want to see what use Maas flow has. I have already used velocity Exit flow. What exactly does the outflow boundary condition mean when applied to a fluent problem? Thank you for your help.
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