# Overview
The stackPlume case simulates the dispersion of smoke from a chimney stack in an
atmospheric boundary layer. Lagrangian particle tracking and a 'scalarTransport'
function object are used to simulate the trajectory of the plume and the
deposition of particles at ground level.

# Atmospheric boundary layer
The atmospheric boundary layer is based on a logarithmic velocity profile with
parameters defined in 'setAtmBoundaryLayerDict'. The atmospheric boundary layer
is applied to the flow both as an initial condition and a boundary condition on
the sides of the domain.

# Plume structure
A function object 'Uyz' is used to extract the y and z components of velocity
and create a new field 'Uyz'. Uyz can be used to visualize the components of
velocity normal to the trajectory of the plume.