Learning Forum

[umutr]

Hello I have a problem about outlet boundary conditions .  I have C-D type Supersonic Air Inlet I try to solve back pressure ratio. My setup options are Operation Condition 0 , Pressure inlet : Total Gauge Pressure 300000Kpa Supersonic/initial 54660 Pa which is equal to M = 2.0 the inlet has a Normal Shock wave at throat then it will diffuse. Outlet condition is 247676 Pa.  Problem is when the flow pass the throat the flow is increasing mach number also end of the simulations ? cross out the total pressure contours Flow doesnt reach outlet conditions. 

Pic about boundary conditions .

Same Problem.

https://www.researchgate.net/post/How_to_assign_a_Back_pressure_in_supersonic_flow_conditions

 

 

[DrAmine]

What is now the question? What are you expecting?

[DrAmine]

Supersonic outlet you cannot assign anything all info is provided from the solution. You might resolve what happens after the outlet in enlarged chamber.

[umutr]

I expect the flow will remain subsonic after the throat . my outlet is not supersonic outlet it is subsonic outlet .  

[Rob]

Pressure inlet-outlet models means Fluent has to solve the mass passing through the domain: this makes the initialisation conditions important. As Amine suggests you may need to add an exit chamber; you may find using a mass flow inlet helps too. 

[umutr]

Thank you @rwollhou and @abenhadj . I done it. 

Best Regards,