Modelling spray drift using a modified air pollution Gaussian tilting plume model

The objective of this research is to evaluate a Gaussian tilting plume model that takes into account the spray characteristics of agricultural nozzles to predict drift. The application of this type of model has proved to be effective for aerial pollution applications. To be applied successfully to the spray drift, the model has to give accurate predictions of the deposits regarding the spray and material characteristics as well as the weather parameters. To reach this objective, the model parameters must be correctly set based on appropriate theoretical basis and experimental data.
Based on wind tunnel measurements, the effect of the most important characteristics of spray droplets from an agricultural nozzle has been modelled using a Gaussian tilting plume approach by discretizing the different droplet classes.

Although the theoretical basis of the model is simple, the predicted drift appeared to be in relatively good agreement with the experimental results.

The discrepancies could be explained by poor fitting of the dispersion model parameters. Further work is required to optimise the value of the model parameters.