Effects of Hole Width on Spray and Mixing Characteristics of Adjustable Pintle Injectors

This study utilized the Volume of Fluid (VOF) numerical simulation method to construct a simplified planar thrust chamber model incorporating a liquid-liquid adjustable pintle injector unit. By varying the hole width, the study investigated its impact on the atomization and mixing characteristics of the injector. The spray field exhibits a fan-shaped structure, divisible into distinct zones, where changes in hole width significantly influence liquid film thickness, spread angle, and initial breaking distance. A horseshoe vortex is observed to form as a result of jet edge interaction with the liquid film, with turbulence intensity diminishing as the hole width increases. Furthermore, the study reveals that as the hole width broadens, the leakage rate of liquid oxygen decreases while that of kerosene increases, subsequently leading to a decline in the kerosene utilization rate. An optimal mixing ratio and the highest kerosene utilization are predicted at a hole width of 1.2 mm, suggesting improved atomization and mixing performance.