Investigation On Numerical Simulation Of Nozzle Internal Flow Of An Aeroengine

The internal flow and sheet breakup behavior of the main circuit of pressure swirl atomizer of an aeroengine have been investigated in this paper. The main purpose is to validate different calculation models and to analyze their applicability by experimental data, and to setup reliable calculation models for the design and experiment of fuel nozzles.The significance of investigation and background of numerical simulation of the fuel nozzle have been summarized. Different types of fuel nozzles and atomization mechanism have been elucidated. Theories and engineering application of multiphase models and have been discussed. Three kinds of turbulence models, realizablek ?ε, Reynolds Stress Model (RSM) and Large Eddy Simulation (LES), have been analyzed to certify the numerical method for simulation. VOF method has been used to simulate the spray process of the main circuit of a pressure swirl atomizer, and the internal flow and sheet breakup behavior have been investigated. Atomization parameters such as pressure, velocity, spray angle and breakup length have been abtained by numerical simulations.Realizable k -εmodel and Reynolds Stress Model have been compared in the simulation of the internal flow of the fuel nozzle. The atomization parameter obtained by Reynolds Stress Model agreed well with the experimental data. Large Eddy Simulation, which takes turbulence of fuel and air into account, has been used to simulate the phenomenon of sheet breakup. Vivid gas-liquid interface, instability wave and primary breakup phenomenon have been captured. The shape of the sheet breakup, captured by simulation, changes with different fuel flux. The mechanism of sheet breakup have been analyzed by combining variations of velocity and turbulent kinetic energy with KH instability theory and turbulence on circumference. The breakup length captured by simulation agreed well with the results of the experiential formulas.