|
[Sponsors] |
Incorrect pressure results and problems with outlet BC's |
|
LinkBack | Thread Tools | Search this Thread | Display Modes |
December 9, 2020, 10:16 |
Incorrect pressure results and problems with outlet BC's
|
#1 |
Member
Jonathan Wells
Join Date: Oct 2020
Location: Indiana
Posts: 44
Rep Power: 5 |
Hello,
I'm fairly new to openfoam, and I've been trying to run a simple shear layer case using rhoPimpleFoam. I have two inlets, one high-speed and one low-speed, one outlet, and the top and bottom boundaries are freestreams with mach numbers corresponding to the adjacent inlet. I will attach a pic for clarity. My first problem is the pressure. I tried to run an RAS to get a decent initial field prior to running LES, and the pressure is just blatantly wrong. The domain is static pressure matched, but the p field in paraFoam shows a lower pressure on the bottom (low-speed). A pic is attached of the results. My other problem is, no matter what I do, the outlet acts as a wall. Once the flow from the inlets reaches the outlet, it doesn't move out of the domain. It just slowly builds backpressure and causes the solution to crash due to negative initial temperature. I thought this was due to making the static temperature equal everywhere in the domain (which is how I've run the simulation in both Fluent and Cobalt with no issues), but setting the outlet pressure to a value of 1 doesn't change this behavior. I will attach my pressure BC file as well. Code:
/*--------------------------------*- C++ -*----------------------------------*\ | ========= | | | \\ / F ield | OpenFOAM: The Open Source CFD Toolbox | | \\ / O peration | Version: v2006 | | \\ / A nd | Website: www.openfoam.com | | \\/ M anipulation | | \*---------------------------------------------------------------------------*/ FoamFile { version 2.0; format ascii; class volScalarField; object p; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // dimensions [1 -1 -2 0 0 0 0]; internalField uniform 1; boundaryField { hsinlet { type waveTransmissive; value uniform 1e5; field p; gamma 1.4; lInf 0.5; fieldInf 1e5; } lsinlet { type waveTransmissive; value uniform 1e5; field p; gamma 1.4; lInf 0.5; fieldInf 1e5; } outlet { type fixedValue; value uniform 1; } upper { type inletOutlet; inletValue uniform 1e5; } lower { type inletOutlet; inletValue uniform 1e5; } faces { type empty; } } // ************************************************************************* // |
|
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Issues on the simulation of high-speed compressible flow within turbomachinery | dowlee | OpenFOAM Running, Solving & CFD | 11 | August 6, 2021 07:40 |
Wind tunnel Boundary Conditions in Fluent | metmet | FLUENT | 6 | October 30, 2019 13:23 |
interFoam (HELYX-OS) pressure boundary conditions | SFr | OpenFOAM Running, Solving & CFD | 8 | June 23, 2016 17:36 |
Pressure results different from Function Calculator and Contour View | mariconeagles96 | CFX | 4 | May 27, 2014 22:09 |
what the result is negatif pressure at inlet | chong chee nan | FLUENT | 0 | December 29, 2001 06:13 |