.. _inputs_multiphase:

Section: MultiPhase
~~~~~~~~~~~~~~~~~~~~

This section is for the MultiPhase physics module, which is required for flows that solve air and water together using the volume-of-fluid method.

.. input_param:: MultiPhase.density_fluid1

   **type:** Real, optional, default = 10.

   Density of the liquid phase, i.e. the one that the vof variable refers to. Recommended value for water is near 1000.

.. input_param:: MultiPhase.density_fluid2

   **type:** Real, optional, default = 1.

   Density of the gas phase, i.e. the one that the vof variable does not refer to. Recommended value for air is near 1.

.. input_param:: MultiPhase.verbose

   **type:** Integer, optional, default = 0

   Verbosity of the ``MultiPhase`` physics output. Verbosity greater than 0 will output conservation statistics, recording the
   total water volume and air volume in the domain, the differences between these and the initial volumes, and the difference
   between the initial momentum and the current momentum. These quantities can be used to confirm conservation properties
   in periodic cases without source terms.

.. input_param:: MultiPhase.water_level

   **type:** Real, optional, default = 0.

   Reference water level of the simulated flow. This value is used by the ``MultiPhase`` physics module to create
   a reference density field, which enables the use of a perturbational gravity term through the ICNS source
   term ``GravityForcing``. This parameter is also used to adjust how the ``GeostrophicForcing`` and ``ABLForcing``
   source terms act in the presence of water. However, this parameter is not needed if the ``OceanWaves`` physics
   module is being used because; the ``water_level`` value is automatically populated in that case from the ``OceanWaves``
   setup parameters.