Modeling Dense Sprays in Liquid Rocket Engines

摘要

Models have been developed to address instabilities inside coaxial injectors and for basic description of primary atomization processes. The coaxial injector simulations have provided a database to quantify the amplitude and frequency of hydrodynamic instabilities within the submerged region of the injector for a variety of design conditions. Results compare favorably with experimental data showing that plume 'flickering' frequencies are correctly predicted by the model. A new nonlinear primary atomization simulation has been developed in a boundary element framework. Here, the influence of the boundary layer at the orifice exit (and hence the orifice geometry) is properly accounted for such that changes in orifice design are shown to affect the subsequent spray. Droplet size distributions have been predicted from first principles with no calibration constants; data agree very well with limited experimental observations.