[oozcan]

Hi all,

velocity inlet and pressure outlet are boundary conditions.

Velocity inlet :

Velocity magnitude: 1.4m/s,
Supersonic/Initial Gauge Pressure (pascal) :0
Temperature 300K ,
Operating pressure :101325 Pa (reference pressure location X,Y,Z=0, gravity is deactivated )


Pressure outlet :

Gauge Pressure (pascal) =0
Backflow Total Temperature :323.15K
Operating pressure :101325 Pa (reference pressure location X,Y,Z=0, gravity is deactivated )

[oozcan]

this is very urget issue.

I have tried giving ''Supersonic/Initial Gauge Pressure (pascal)'' :150000 Pa (1.5 bar) in velocity inlet as a static pressure.Still ,there's nothing new

[CeesH]

backflow is not necessarily a problem, it could be that it's a physical phenomena in your setup. If you do regard it as an issue, maybe the placement of the domain boundaries is wrong; you may have to extend the domain a bit.

Anyway, why is it giving you problems?

[oozcan]

Originally Posted by CeesH

backflow is not necessarily a problem, it could be that it's a physical phenomena in your setup. If you do regard it as an issue, maybe the placement of the domain boundaries is wrong; you may have to extend the domain a bit.

Anyway, why is it giving you problems?

Thank you Cees for approach to issue

volumetric flow rate (velocity_inlet) has been constant following 50. iterations. ''Supersonic/Initial Gauge Pressure (pascal)'' :150000 Pa (1.5 bar) has worked! (volumetric flow rate has been increasing thanks to temperature in outlet_pressure (because pressure inlet_velocity and pressure in outlet_pressure was equal)

''the placement of the domain boundaries '' are correct
''approach to physical phenomena in setup is right way for answer. (attention should be paid for initial gauge pressure )

I am going to let you know what it happens.

Thank you

[oozcan]

Originally Posted by CeesH

backflow is not necessarily a problem, it could be that it's a physical phenomena in your setup. If you do regard it as an issue, maybe the placement of the domain boundaries is wrong; you may have to extend the domain a bit.

Anyway, why is it giving you problems?

The problem has came up again, domain having outlet_pressure is going to extended.

[oozcan]

The reason why flow direction is not as I have modelled or thought on is relevant to turbulent viscosity ratio in pressure outlet? pressure outlet is actually affected by inlet pressure value and turbulence flow. Moreover, pressure outlet is open to atmosphere at the same time.

Question is that is there any missing input I have written above?

and, what is turbulent viscosity ratio value in pressure_outlet (according to scenerio I have told)? (beta; 0,1 or 0,2 , I have specified ''5'' in BC)