# Test Case for Turbulent Dispersion for More Than Two Phases

## Description

This case is designed to illustrate and test implementation of the turbulent
dispersion force into addonMultiphaseEuler. Water is initialised with a limited
turbulent energy, which is decaying exponentially in time. A region of increased
air volume fraction at the centre of the domain is smeared out due to turbulent
dispersion force as long as water turbulent kinetic energy is still strong
enough.

The case is setup with two phases and with three phases and results are
compared.

## Technical Information

* 1D
* 15 cells
* 1m
* Turbulent dispersion: constant coefficient model with Ctd=1
* kOmegaSST (baseline) turbulence model for water, initialised with constant
  values for k.water, omega.water and nut.water
* Initialised with zero velocity

## Pre-Processing

A region with 50 % disperse air (25 % air1 and 25 % air2) is placed in the
centre of the domain with setFields.

## Post-Processing

Line data are obtained with singleGraph along the domain. Air volume fraction
along this line may be plotted via the gnuplot script in the validation
directory for different time steps. Probe data is gathered in the centre of the
domain via probes. k, omega and nut for the water may be plotted over time with
the same gnuplot script in the validation directory.

For automated testing, air volume fraction data at end time t=100s is compared
to reference data, which is also located in the validation directory.

Line data of alpha.water is compared between the two phase and the three phase
cases.
