A New Modeling Method for Spray Angle Prediction of Liquid–Liquid Pintle Injector

Abstract

Accurate predictions of the spray angle play a significant role in the design and operation of the pintle injectors. However, existing prediction models are often based on idealized assumptions and expressed as the functions of the jet-to-film momentum ratio corrected by different coefficients, which result in the weak generalization abilities of these models. In the present study, a prediction model for the spray angle of the liquid–liquid pintle injector was established and verified. The initial interactions between the radial jet column and the axial jet film were considered, and the deflected trajectory of the transverse jet column was derived theoretically; then, the spray angle of the pintle injector was thus obtained. Specially designed experiments were carried out, and the spray angles were extracted by using high-speed photography. The comparisons between the experimental and the predicted results clearly exhibit the limitations of the traditional models that are based on the momentum ratio only, and they prove the accuracy of our new model.