Behavior of buoyant moist plumes in turbulent atmospheres

Abstract

A widely applicable computational model of buoyant moist plumes in turbulent atmospheres has been constructed. To achieve this a one dimensional Planetary Boundary Layer (P.B.L.) model has been developed to account for atmospheric turbulence while the two dimensional time dependent fluid mechanics equations which govern plume behavior are numerically integrated. A cloud microphysics model has been incorporated into the basic numerical code to account properly for the water content of the plume. The overall dynamics of the plume is quite general. The buoyancy source in the plume include both the sensible heat and the latent heat absorbed or released in the plume. The turbulence of the plume accounts for buoyancy generated or destroyed turbulence and a universal k-E model has been set up along with the k-0 model.

The model is validated against complex field cases to demonstrate its ability to reproduce solutions to problems that are known. Comparisons to visible plume data show that both the dynamics of the plume are calculated with an acceptable accuracy. Comparisons with "conventional" entrainment model show that the model can simulate plumes better since it takes into account more physical phenomena.