|
[Sponsors] |
Issue with Exponential Pressure Increase in rhoCentralFoam |
![]() |
|
LinkBack | Thread Tools | Search this Thread | Display Modes |
![]() |
![]() |
#1 |
New Member
Join Date: Nov 2023
Posts: 17
Rep Power: 2 ![]() |
I'm encountering an issue when trying to utilize a fixed pressure boundary condition instead of a zeroGrad where the value would float. I'm attempting to simulate a supersonic aircraft inlet and what happens when I choke the flow.
For these cases, I have a geometry with mainly walls, 1 inlet, and two outlets. One of the outlets belongs to the downstream portion within the aircraft inlet. I'm using an expanded duct to use a constant back pressure as one of the BCs, from this article on page 40 of the pdf: https://apps.dtic.mil/sti/tr/pdf/ADA291365.pdf With initial cases, I'm allowing the outlet in question to be zeroGrad to let the pressure float to determine what values I should look to test around. I get to uniform values around 700kPa. However, when I try to use a uniform pressure boundary condition on that outlet, I notice an exponential rise in the pressure that grows without bound. I have not ran the simulations beyond .25s so I'm unsure about its stability in the long term but regardless, this is problematic, since I'm using the same pressure value as was seen in the zeroGrad test. I am under the impression that I should be achieving similar results by setting the uniform pressure BC as with the zeroGrad case. I have pictures and plots within my case on github in the README portion which helps visualize it. https://github.com/CChe36/0_22/tree/main Can anyone provide insight as to why this may be happening and what I may be missing? Thank you. |
|
![]() |
![]() |
![]() |
|
|
![]() |
||||
Thread | Thread Starter | Forum | Replies | Last Post |
Increase in flow rate decrease in Outlet pressure. | trovilb1 | System Analysis | 1 | December 5, 2017 07:22 |
Pressure Inlet Boundary Condition Issue | zoeburton1987 | FLUENT | 0 | May 15, 2012 09:20 |
Pressure boundary condition issue | Vijay | FLUENT | 0 | April 6, 2012 13:35 |
Neumann pressure BC and velocity field | Antech | Main CFD Forum | 0 | April 25, 2006 02:15 |
Gas pressure question | Dan Moskal | Main CFD Forum | 0 | October 24, 2002 22:02 |