# How can I set the inlet pressure?

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 August 18, 2003, 15:52 How can I set the inlet pressure? #1 moon Guest   Posts: n/a For an incompressible flow, I use the velocity inlet and outflow condition. How can I set the inlet pressure(7bar)?

 August 18, 2003, 16:10 Re: How can I set the inlet pressure? #2 Jason Guest   Posts: n/a In Define --> Operation condition The pressure in boundary condition(if you defined) is based on this pressure, i.e. gauge pressure.

 August 18, 2003, 17:11 Re: How can I set the inlet pressure? #3 moon Guest   Posts: n/a default value is 1bar in operating pressure. I want to make the pressure 7bar or above is it possible without any treatments

 August 18, 2003, 18:02 Re: How can I set the inlet pressure? #4 Jason Guest   Posts: n/a sure you can change it directly. Bearing in mind that the pressure will change gas density and hence velocity if you are using mass_flow_inlet and defining material density as incompressible ideal gas.

 August 18, 2003, 19:08 Re: How can I set the inlet pressure? #5 moon Guest   Posts: n/a I define material density as incompressible ideal gas. when I set the operating pressure 7bar, density become 7times higher than that of 1bar. I just want to use air under the 7bar pressure. How can I make it?

 August 18, 2003, 19:21 Re: How can I set the inlet pressure? #6 moon Guest   Posts: n/a when I set the material, fluent questions whether overwrite the air or make new material. I made it new. is it wrong?

 August 19, 2003, 10:23 Re: How can I set the inlet pressure? #7 Rahul Hiwale Guest   Posts: n/a Hi Moon, If you need density of air at 1 bar then use constant density and give operating pressure as 7 bar. You can also use inlet pressure bc in that case use pressure as 7 bar + kinetic pressure (1/2.rho.v2) for incompressibale flow. Fluent won't ask you to overwrite unless you change fluid/solid name. If you overwrite it will set that new mateial as default material instead of old material. Rahul

 August 19, 2003, 14:17 Re: How can I set the inlet pressure? #8 moon Guest   Posts: n/a Thank you and Jason for your answer. If I have a problem with property variation(air) due to high heat flux and can't use constant density, what must I do? I use an incompressible ideal gas law for density and other properties as a function of temperature. all properties varies mainly with temperature. I use a segregated solver, not coupled. is it wrong?