Upstream BC Types - interFoam (OF 2.3.1)
 

Hello All,

I am developing a model of a fishway and have been wrestling with finding and applying a suitable boundary condition in interFoam that will adequately model a fixed water surface elevation at the upstream end. The upstream and downstream water surface elevations are known (velocities, etc are not). A little assistance with the identification and prescription of suitable type (with example) would be great.

To date I have divided the upstream patch into two sections one for water (alpha.water) between the invert of the channel and the operating design elevation with a fixedValue of 1 (setFields is also set at this level) and the remainder of the upstream inlet wall is defined as alpha.air boundary. The model initiates but crashes after several iterations and I interpret the error message to mean a BC issue - hence why I would like to identify a better BC arrangement which will also allow more efficient

I created the mesh using snappyHexMesh and the checkMesh report was OK, the mesh is a first pass and I will extend and refine in future once I get this model running. Attached are the model case files.

FYI, I have also searched the forum looking for similar cases and while there are several posts they have not helped in addressing this issue.

Any assistance would be greatly appreciated.
Regards JFM

Hi John,

I've been dealing with a similar difficulty. I'm trying to adapt the spillway tutorial to version 2.3.
This tutorial is available in https://www.hpc.ntnu.no/display/hpc/OpenFOAM+-+Spillway+Tutorial and was developed for version 2.1. It uses a water inlet similar to the one that you described.

I wasn't able to make this case run in version 2.3, it always crashed. To make it work I had to replace the water inlet condition with variableHeightFlowRateInletVelocity as is done in the weirOverflow tutorial. This tutorial you can find in tutorials/multiphase/interFoam/ras directory.

I know this is not exactly what you are looking for, because you need fixed elevation but at least you can make the simulations run.

Best Regards,
Paulo