For constant density flows, the buoyancy source term is approximated with the Boussinesq model:
|
| (112) |
where
is the gravitational vector and the quantities
and
are the coefficient of bulk expansion and the operating temperature, respectively.
The piezometric pressure is then given by:
|
| (113) |
where
is a position vector, termed the operating altitude, at which the piezometric and static pressures are equal.