Model for three-dimensional distribution of liquid fuel in supersonic crossflows

The spatial oscillation distribution characteristics of liquid jet in a supersonic crossflow were studied experimentally. Two models were built for predicting the oscillation distribution in the longitudinal and three-dimensional space, respectively. The experiments were carried out in a blow-type wind tunnel with Mach number of 2.1, and various conditions were studied, including stagnation pressure of the supersonic airflow (642~1010kPa), nozzle diameters (0.48~2.07mm), distance down from nozzle (10~125mm), practical pressure ranges (0.5~4.5MPa), and jet-gas momentum flux ratio ranges (0.11~10). Pulse laser background imaging method (PLBI) was used to shoot the transient spray distribution structures from the side and PIV method was used to capture the structures in cross-sections. A key parameter (Spray Proportion, γ) was defined to quantify the spatial oscillation distribution of the spray. A longitudinal spray oscillation distribution study was carried out, a spray boundary band model was established, and the model accuracy was verified. In addition, a piecewise function of the egg-shape curve and parabola was adopted to fit the contour line to establish the model for the spatial distribution of the spray in the cross-section. Based on various cross-section distributions with multi-parameters, a mathematical model is proposed to describe the liquid spray spatial distribution.