Abstract
The behavior throughout all over a plane forced plume is predicted by a differential and integral hybrid model. The differential boundary layer equations are used to develop an integral formulation which can describe the streamwise variations of mass, momentum and buoyancy fluxes. The eddy viscosity coefficient connects with the entrainment coefficient in this theoretical derivation. It enables to derive a relationship between the entrainment velocity and the Richardson number theoretically. It shows that the entrainment coefficient increases from 0.065 for a jet to 0.156 for a plume with an increase of the Richardson number. It is found that this model reasonably predicts the distributions of mean velocity, mean buoyancy and Reynolds stress and their streamwise variations.
