|
[Sponsors] |
![]() |
![]() |
#1 |
Senior Member
Brett
Join Date: May 2013
Posts: 212
Rep Power: 14 ![]() |
Hi guys,
I've got an interesting situation. I've got 2 inlet patches, each set to: Inlet1 { type flowRateInletVelocity; volumetricFlowRate constant 65; } Now after monitoring the velocity magnitude at a few slices in the domain im happy the simulation has converged. In the U file at one of these advanced time steps, think its time step 4840. I have this: Inlet1 { type flowRateInletVelocity; volumetricFlowRate constant 65; extrapolateProfile false; value uniform (0 6.02545 0); } All look ok right?? Well if I try this command: postProcess -func 'patchAverage(name=Inlet1,U,p)' -latestTime surfaceFieldValue patchAverage(name=Inlet1,U,p): total faces = 865 total area = 10.7876 Time = 4840 Reading fields: volScalarFields: p volVectorFields: U Executing functionObjects surfaceFieldValue patchAverage(name=Inlet1,U,p) write: average(Inlet1) of U = (0 6.02545 0) average(Inlet1) of p = 101325 End Again this is what I expect. This is where it gets weird: If I run postProcess -func "flowRatePatch(name=Inlet1)" -latestTime I get....... surfaceFieldValue flowRatePatch(name=Inlet1): total faces = 865 total area = 10.7876 Time = 4840 Reading fields: surfaceScalarFields: phi Executing functionObjects surfaceFieldValue flowRatePatch(name=Inlet1) write: sum(Inlet1) of phi = -30.743 End So how can it be a surface of approx 10m2 with an average velocity of approx 6m/s giving my requested flow rate of 65m3/s (approx) but have a flux across it equal to 30.743m3/s??? Any thoughts???? |
|
![]() |
![]() |
![]() |
![]() |
#2 |
Senior Member
Yann
Join Date: Apr 2012
Location: France
Posts: 1,169
Rep Power: 27 ![]() |
Hello Brett,
What solver are you using? First thing coming to my mind would be volume flowrate VS mass flowrate. |
|
![]() |
![]() |
![]() |
![]() |
#3 |
Senior Member
Brett
Join Date: May 2013
Posts: 212
Rep Power: 14 ![]() |
Hi Yann,
Just simpleFoam, so I've not defined the density. Any other thoughts? |
|
![]() |
![]() |
![]() |
![]() |
#4 |
Super Moderator
Tobias Holzmann
Join Date: Oct 2010
Location: Bad Wörishofen
Posts: 2,711
Blog Entries: 6
Rep Power: 51 ![]() ![]() ![]() |
Hi,
without knowing your case. I think you are doing anything wrong - somewhere. I just redone all your steps in the pitzDaily case and everything works fine. No problems at all an all results are as expected. By the way, please use code-tags.
__________________
Keep foaming, Tobias Holzmann |
|
![]() |
![]() |
![]() |
![]() |
#5 |
New Member
Harsh K
Join Date: Mar 2021
Posts: 4
Rep Power: 5 ![]() |
@Bdew8556 I'm having the exact same issue but the ratio of volumeFlowRate and phi is coming out as 30 in my case.
Have you managed to solve this issue? |
|
![]() |
![]() |
![]() |
Tags |
mass balance error, openfoam, scripting |
|
|
![]() |
||||
Thread | Thread Starter | Forum | Replies | Last Post |
Mass Flow Rate Over a Sampled Surface | GRAUPS | OpenFOAM Post-Processing | 8 | April 21, 2021 08:11 |
mass flow rate | majidroozbahani | OpenFOAM Post-Processing | 6 | February 4, 2019 07:59 |
setting OUTLET flow rate equal to INLET flow rate | spitchers | OpenFOAM Programming & Development | 0 | March 22, 2018 06:33 |
No flow rate in outlet with advective velocity | rcastilla | OpenFOAM Running, Solving & CFD | 0 | July 19, 2017 04:34 |
Problems with mass flow rate, pressure and velocity average values | LucasCosta | OpenFOAM Post-Processing | 2 | September 14, 2016 14:07 |