VALIDATION OF Σ−YLIQ ATOMIZATION MODEL IN PRESSURE SWIRL ATOMIZER

Abstract

In many combustion and agricultural applications atomizers are used to increase the surface area of the liquid to ensure high rates of mixing and improve evaporation. The most common, simple, and reliable atomizer is the pressure swirl atomizer. This atomizer is said to have quality and effective atomization compared to others and induces swirling motion to the liquid and gives a hollow cone spray with air core as it emerges from the exit orifice. To enhance the understanding and prediction of the atomizing characteristics various atomization models are used and need to be investigated experimentally. This paper presents a validation of the Σ−Yliq atomization model of two-phase flow in a pressure swirl atomizer using commercial CFD star-cd code and laser-diffraction based drop measurements. To obtain the best results for the droplet mean diameter between the prediction and the experiment in terms of turbulence different k-e models were evaluated. The results show that the computational predictions of Sauter Mean Diameter (SMD) for the model have a good agreement with most of the experimental measurements in the radial positions when standard k-ɛ turbulence was used. However, more divergence was observed between the predictions and the experimental measurements when the RNG and Realizable k-ɛ turbulence models were used in the predictions. It was also observed that the model has good agreement with the mean droplet measurements on the spray centreline and radial axis with a percentage error of less than five percent.