Numerical Simulation On The Nozzle Two-phase Flow Characteristics Of An Internal-mixing Air-assisted Atomizer

The internal-mixing twin-fluid atomizer is widely used in industrial field,because it has lots of advantages,such as low air consumption,hardly blocking,fine droplets,and simple structure,which makes that the atomizing effect of the internal-mixing twin-fluid atomizer is better than the single-phase atomizer.In this paper,the method of combining the experiment and numerical simulation is adopted to investigate the internal flow condition of the atomizer and the effects of structure parameters are also studied.The numerical simulation method is adopted to study the influence of structure parameters and liquid types on the internal and external flow conditions.In order to verify the results of simulation,the experiment method is adopted.Under certain operating conditions,the multiphase flow model and turbulence model is used to simulate,and the simulation results are compare with the experiment results.Finally,the multiphase flow model of VOF and the turbulent model of SST ? are chosen to investigate further more.In this paper,it is necessary to create the geometric model and the grid model at first,the parameter values are determined by the operating conditions.The structure parameters of the spoiler angle,the nozzle length-diameter ratio and the angle between gas inlet and the horizontal axis are adopted to study their influence on average export velocity,external mass flow rate and average turbulent energy.It shows that the spoiler can effectively improve the distribution of the flow pattern inside the nozzle,and has a strong promotion effect on mixing process.The influence of viscosity and surface tension on internal and external flow condition is also studied.It shows that changing viscosity and surface tension has no significant improvement in the distribution of two-phase flow patterns,and the material properties of liquid phase have little effect on flow patterns.