Flow-Independent Liquid Jet-in-Crossflow Injection Using Physical Obstructions

The present work explores a novel flow-independent liquid injection scheme, incorporating solid obstructions to alter the key mechanisms controlling the liquid breakup and trajectory. These obstructions, designated pintiles, minimize the variability of fuel injection dynamics over a range of operational conditions. To better understand these mechanisms, a variety of solid pintile obstructions are designed and incorporated into a liquid jet in crossflow experiment. The design parameters of interest include the fraction of the liquid jet orifice blocked by the pintile (orifice coverage), the vertical height of the pintile in the liquid stream, and the angle of the obstruction with respect to the injection plate. All pintiles are tested at non-reacting ambient temperature and pressure conditions over a range of engine relevant Reynolds numbers (Re = 171,500-343,000), momentum flux ratios (Q = 4-45), and Weber numbers (We = 20-80) to understand the leading order effects the solid-liquid-gas interaction has on the liquid breakup and trajectory control. The results demonstrate that the most consistent jet trajectories are achieved with pintiles with a high orifice coverage, a large height, and an angle of 45 deg. Other parameters, such as the transverse spread of the liquid jet and droplet size distributions, are quantified to ensure that consistent jet trajectories can be achieved without imparting adverse effects on other relevant combustion characteristics. The results provide a foundational, first-order understanding on how to minimize variability of liquid injection across engine relevant Reynolds numbers, Weber numbers, and momentum flux ratios.

Automated summary

This study introduces solid pintile obstructions to alter the key mechanisms controlling liquid breakup and trajectory, achieving the most consistent jet trajectories. By testing various parameters, a stable method for jet trajectory design is found.