Two Conditions in the inlet.

June 27, 2003, 16:58

Hi all. I'm a beginner in CFX 5 /CFD. How can I define two properties in a same inlet condition. ( like static pressure and mass flow )? Is it possible? I wish to define a nozzle with an inlet condition of CO2 liquid with pressure and mass and the outlet will be by atmospheric pressure. Does somebody have worked with a nozzle like that? I'll have two phases.

June 28, 2003, 09:09

Hi Lucio,

The pressure difference between your inlet and outlet, along with your wall boundary conditions, will determine the mass flow rate. Attempting to specify pressures and the flow rate is overspecifying the problem and cannot be done.

The exception to this is a supersonic inlet, in which case velocity and pressure must be specified (since the downstream pressure is not communicated upstream in a supersonic flow).

Regards, Robin

June 27, 2003, 16:58	Two Conditions in the inlet.	#1
Lucio Guest Posts: n/a	Hi all. I'm a beginner in CFX 5 /CFD. How can I define two properties in a same inlet condition. ( like static pressure and mass flow )? Is it possible? I wish to define a nozzle with an inlet condition of CO2 liquid with pressure and mass and the outlet will be by atmospheric pressure. Does somebody have worked with a nozzle like that? I'll have two phases.

June 28, 2003, 09:09	Re: Two Conditions in the inlet.	#2
Robin Guest Posts: n/a	Hi Lucio, The pressure difference between your inlet and outlet, along with your wall boundary conditions, will determine the mass flow rate. Attempting to specify pressures and the flow rate is overspecifying the problem and cannot be done. The exception to this is a supersonic inlet, in which case velocity and pressure must be specified (since the downstream pressure is not communicated upstream in a supersonic flow). Regards, Robin

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