For an incompressible flow, I use the velocity inlet and outflow condition. How can I set the inlet pressure(7bar)?

In Define --> Operation condition The pressure in boundary condition(if you defined) is based on this pressure, i.e. gauge pressure.

default value is 1bar in operating pressure. I want to make the pressure 7bar or above is it possible without any treatments

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.

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?

when I set the material, fluent questions whether overwrite the air or make new material. I made it new. is it wrong?

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

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?