Abstract: The characteristics of the spray produced by impinging jets atomization is theoretically analyzed.Depending on Weber number,two breakup regimes of sheet are considered with transition occurring at Weber numbers between 500 and 2000.In the low Weber number regime ( We ≤2000),the sheet breakup is due to Taylor cardioidal waves.While in the high Weber number regimes,the sheet disintegration is caused by growth of Kelvin-Helmholtz instability waves.The model uses an analogy with the oblique impact of a liquid jet on a wall.At Weber number less than 2000,mathematical expressions to predict the sheet thickness and shape during formation of nonviscous liquid sheet are derived from mass conservation and momentum conservation equations by reference to theoretical results and empirical correlations reported in the literature.The numerical results are in good agreement with experimental data available in the literature.Predictions of the spray droplet size and distribution formed by the disintegration of the viscous liquid sheets are also obtained by use of the mathematical formulation developed for fan spray injectors.This model can be used to estimate the size range and distribution of droplets formed by impinging jets atomization in quasi static surroundings.