View Issue Details
|ID||Project||Category||View Status||Date Submitted||Last Update|
|0001700||OpenFOAM||[All Projects] Bug||public||2015-05-20 20:53||2015-06-15 18:51|
|Status||closed||Resolution||no change required|
|Fixed in Version|
|Summary||0001700: Mass conservation in twoPhaseEulerFoam|
|Description||In fluidizedBed tutorial at outlet an increase in air mass flow rate and total mass flow rate (air+particles) is being observed even though the boundary conditions are set in such a way to ensure the zero particles mass flow out of the domain. We can check the increase in mass flow rate by following commands|
patchIntegrate phi.particles inlet = 0
patchIntegrate phi.particles outlet = 0
patchIntegrate phi.air inlet = 0.013
patchIntegrate phi.air outlet = 0.017
|Steps To Reproduce||No specific steps are required to reproduce this problem.|
|Additional Information||The boundary condition for alpha.particles at inlet and outlet are set to fixedValue = 0 (initially zeroGradient) and 0/U.particles/outlet also fixedValue = 0 (initially zeroGradient) to make sure no particle is moving outside the geometry. It shows no particle is moving in and out of the domain but the air mass flow rate increases. |
I was stated in a bug report that this problem has been fixed in 2.3.x but this problem still exist both in 2.3.x and 2.3.1 as well.
Here is the link for previous bug report:
This problem is not present in OpenFOAM2.1.1
|Tags||No tags attached.|
twoPhaseEulerFoam in compressible in OpenFOAM-2.3.x and air is treated as a compressible phase whereas in OpenFOAM-2.1.1 the air is treated as incompressible. So to create the equivalent behavior you would need to select a constant density model for the air.
In the current setup in OpenFOAM-2.3.x the inlet and outlet air fluxes vary over time and will only be equal on average. If you average these fluxes over time for a long enough time after the case has reached a fully-developed state you should find they are equal within the continuity error of the case.