Modelling a Multi-phase Plume in a Cross-flow - an Agricultural Application

A generalized set of equations of motion suitable for modelling a multi-phase plume in a crossow have been identi ed. Simpli cation of the equations is presented for a fully evolved two phase three dimensional plume of low curvature by using radially averaged values of velocity and droplet radius to calculate the tangential momentum balance between the phases. This balance, augmented to include the e ects of an induced boundary layer ow, is then combined with a normal force component generated by the crossow to allow the trajectory of the plume to be determined. Particular attention is paid to use of the equations in conjunction with a liquid droplet ballistics model to simulate the water distributions as produced by medium and large scale irrigation sprinklers, (guns), operating in cross winds.