The Effects of Pressure Difference in Nozzle’s two Phase Flow on the Quality of Exhaust Mixture

In most applications of nozzles with gas-liquid two-phase flow, the quality of mixture inthe exhaust of nozzle as well as the flow velocity are the most important parameters. On theother hand, in some industrial applications, such as industrial painting or water injection in forced induction (turbocharged or supercharged) internal combustion engines, the quality of the spray is the main goal of design. In this case, and for improving the injectionperformance the air-water two phase nozzle injection flow is more remarkable subject. There are two options for this purpose, premixed or un-premixed air-water in entrance of the nozzle. In both cases, the nozzle not only has to accelerate gas and liquid to extra high velocity, but also it is supposed to have a high quality mixture in exhaust of nozzle. In this study, the turbulent gas-liquid two-phase premixed/un-premixed flow through the nozzle issimulated by the Eulerian-Lagrangian approach. The gas phase is treated as a continuum by solving the time-averaged Navier-Stokes equations, while the liquid as a dispersed phase issolved by tracking a large number of droplets through the calculated flow field. Thepressure, velocity and Mach number profiles as well as air flow-rates and particle residence time inside the nozzle for various back pressure values have been computed. This work has been validated by comparing pressure profiles and air flow-rates between simulated results and available experimental results for un-premixed nozzle flow

کلیدواژه ها:

Compressible Flow ، Multi-phase Flows ، RANS: Reynolds Averaged Navier-Stokes ، Supersonic ، Turbulence Models ، Two-phase Flows Premixed ، Un-premixed Nozzle Flow