The Use of Computational Fluid Dynamic Code for Modelling Spray from a Mistblower

Abstract

A commercially available Computational Fluid Dynamics (CFD) code FLUENT has been used to simulate an air jet from one of the most simple forms of air-assisted sprayer, a vehicle-mounted mistblower. The sprayer consisted of an assembly of nozzles incorporated within a single outlet from a centrifugal fan. The CFD simulation was initially set up in two dimensions using standard boundary and turbulence conditions. The predicted flow field was then compared with experimental data, which were measured with a three-dimensional ultrasonic anemometer. The simulation was then improved by extension to three dimensions and by the incorporation of the measured turbulence parameters. Comparisons between three-dimensional simulations and experimental measurements, showed satisfactory agreement for major characteristics of the air jet such as centreline velocity, and horizontal velocity profiles. Drop dispersion simulations indicated that the CFD code should be modified to predict accurately the dispersion of heavy drops over large distances.