Characterization of a kerosene liquid jet injected in a high temperature Mach 2 supersonic crossflow

TL;DR

This study experimentally investigates the behavior of a kerosene liquid jet injected into a Mach 2 supersonic crossflow at high temperatures, providing new high-resolution data on atomization, penetration, and shock structures.

Contribution

It offers novel high spatial and temporal resolution measurements of kerosene jet atomization and penetration in high-temperature supersonic flows, expanding understanding under realistic conditions.

Findings

Detailed characterization of liquid jet atomization and droplet trajectories.

Measurement of jet penetration and shock wave structures.

Insights into the influence of temperature and injection ratio on jet behavior.

Abstract

Near field liquid structures and penetration of a kerosene jet injected in a Mach 2 crossflow were studied experimentally in the LAPCAT-II Dual Mode Ramjet Combustor at Onera, using high spatial and temporal resolution imaging techniques. The experiments performed in this study provide measurements in high temperature conditions, with kerosene as liquid fuel to bring new data in these conditions. The fuel spray is injected through a single orifice, perpendicularly to the supersonic flow, at temperatures from ambient to 1500 K and jet-to-crossflow momentum flux ratio from 3.1 to 8.6. Five different test cases are defined to show independently the influence of the injection ratio and the supersonic flow temperature on the liquid jet atomization. A high spatial resolution imaging system is used to detail the characteristic spatial scales of this atomization process in the supersonic crossflow. The surface waves and droplets produced in the windward side of the liquid jet are characterized qualitatively. High-resolution visualizations bring a new insight of the droplet trajectories in the leeward region of the jet. Schlieren imaging is used to detail the complex shock wave structures in such a supersonic flow. Penetration of the kerosene jet is measured by shadowgraphy and schlieren imaging in five test cases and compared to other studies of the literature whenever it is possible. High-speed schlieren performed at 210 kHz is also performed to capture the temporal dynamics of the shocks and measure the liquid jet velocity.