hippo

Hippo is a MOOSE app wrapping OpenFOAM's fluid solver. It provides tools for solving coupled conjugate heat transfer problems.

Some simple 1 and 2D validation cases can be found in the tests.

Using Hippo

Hippo's documentation is a work in progress, and can be found here. It includes an example of how to set up a coupled conjugate heat transfer problem.

Install/Build

Note: Only tested with GCC.

OpenFOAM

Unfortunately hippo relies on patching OpenFOAM, there is a script scripts/install-openfoam.sh that will clone OpenFOAM-10, apply the patch, and build it.

First install the build dependencies:

apt install \
    bison \
    flex \
    libptscotch-dev \
    libqt5opengl5-dev \
    libqt5x11extras5-dev \
    libxt-dev \
    make \
    paraview \
    paraview-dev \
    qtbase5-dev \
    qttools5-dev \
    qttools5-dev-tools

Then run the script (use flag -h for help, this will take ~1 hour):

bash ./scripts/install-openfoam.sh

To set the OpenFOAM build options (e.g., Opt or Debug mode), copy scripts/openfoam-prefs.sh to ~/.OpenFOAM/prefs.sh, and update the environment variables within. The variables will be loaded when <path/to/OpenFOAM>/etc/bashrc is sourced (which is done automatically by the install script).

Moose

Follow instructions here to build MOOSE.

Hippo requires MOOSE release 2024-09-05-release or higher.

Environment

Set (recommend direnv for this)

MOOSE_DIR=/path/to/moose/dir
MPI_ROOT=/path/to/mpich/root
MPI_ARCH_INC="-I/path/to/mpi/includes"
MPI_ARCH_LIBS="-L/path/to/mpi/libs -lmpi"
source /path/to/OpenFOAM/etc/bashrc

Build

Once the dependencies are built, then (in theory) you should be able to make in the root directory:

make

Or, for a debug build:

METHOD=dbg make

Tests

Hippo's tests are written using MOOSE's test harness system. Just run ./run_tests.

Note that you must have the required Python packages installed:

pip install -r requirements.test.txt

Quality

Some code quality checks are set up with pre-commit.

Install the pre-commit hooks to run on each new commit:

pre-commit install

Run the hooks manually:

pre-commit run --all

To bypass the pre-commit checks, use the --no-verify (or -n) flag:

git commit --no-verify

Notes

This is a work in progress. So far, Hippo can:

• Create a 2D MOOSE boundary mesh from the boundary of an OpenFOAM mesh.
• Run a fluid solver case via a MOOSE input file.
• Transfer temperatures and or heat fluxes from an OpenFOAM mesh to the MOOSE boundary mesh.
• Set OpenFOAM temperature field boundary conditions using values from a MOOSE mesh.

Floating Point Error Trapping

If you have floating point error (FPE) trapping enabled in OpenFOAM, you may run into errors when running Hippo.

Hippo input files that run a MOOSE case do not require a Kernel or variables. However, MOOSE will still happily go off and calculate a residual. Since there are no variables defined, the residual calculation results in a division by zero and an FPE signal. OpenFOAM will catch this signal and abort the application.

Either of these two workarounds will work:

1. Disable trapping for floating point exceptions. unset FOAM_SIGFPE && unset FOAM_SETNAN.

2. Add a dummy variable to the MOOSE input file. E.g.,

   [Variables]
     [dummy]
       initial_value = 999
     []
   []