A computational fluid dynamics (CFD) investigation of the flow field and the primary atomization of the close coupled atomizer

The gas flow fields of four atomizers were analyzed by both k–ɛ turbulence model and Reynolds stress turbulence model (RSM). The scattering angle of the main part of gas spray increased from 15.0° to 17.4° given by k–ɛ model and 17.2° to 19.0° given by RSM model, as the nozzle intersection angle increased from 5° to 65° at the operating gas pressure of 1.0 MPa, which also moved the merging position of the annular peak. There is a high pressure area downstream of the delivery tube which contributes to the sheet breakup. Comparing the simulation results with the experimental data, it is found that RSM model is more accurate than k–ɛ model and proved that computational fluid dynamics is an effective method to simulate the gas flow of the close coupled atomizer.

► We model the gas flow fields with k–ɛ turbulence model and Reynolds stress turbulence model (RSM).
► We examine the scattering angle of main part of the flow field.
► The primary breakup is controlled by the gas pressure near the delivery tube.
► The results given by RSM model are more accuracy than those given by k–ɛ model.