Characteristics of Spray Angle and Discharge Coefficient of Pressure-Swirl Atomizer

A widely distributed spray is an important feature for an atomizer which is required in various applications such as gas cooling, gas turbine combustion, and fluidized bed granulator. Pressure-swirl atomizer is an example of atomizer which provides a wide spray angle through the swirling effect inside the atomizer. One of the important parameters affecting spray angle is atomizer geometrical constant, K. Another important parameter of pressure-swirl atomizer is discharge coefficient, Cd. Discharge coefficient describes the throughput of the liquid flow. An experimental test-rig was constructed to conduct the performance test of the atomizer. Acquired images were analysed using image-processing software. It was found that K has inverse relation with spray angle and direct relation with Cd. Prediction of spray angle and Cd using existing correlations also yields similar trends with the experimental results, but some parameters still need to be considered to perform an accurate prediction.