BUOYANT PLUME RISE IN A LAGRANGIAN FRAMEWORK

For the dispersion of buoyant material, the interaction with the environment by entrainment forms a serious obstacle for a formulation in a Lagrangian framework. Nevertheless an outline is given here on how buoyant plume rise in a Lagrangian sense could be described. Though the method contains a number of heuristic elements. it has all the advantages of a Lagrangian formulation. It is shown that it is possible to formulate a Lagrangian model which both is able to recover the classical formulations for plume rise in a calm environment and to accomodate more recent Eulerian formulations in a turbulent environment, Moreover, the method offers excellent possibilities to include the turbulent characteristics of the plume's, environment and arbitrary stratifications of the boundary layer. These facts make it attractive for various practical applications. Some examples are given which illustrate this.