Jet-in-crossflow is an interaction between a fuel jet and air crossflow commonly found in jet engines. The crossflow is used to break up or atomize the fuel jet for downstream combustion. This interaction between fluids while at low speeds, is predictable, varies greatly at higher speeds. This investigation seeks to (1) create a mechanism for jet-in-crossflow, using mechanical pintles, that is independent of velocity to help increase the predictability and reliability of jet engines and (2) identify key design parameters that will lead to flow independence. Parameters investigated in this experiment include pintle height, angle, and percent of pintle coverage into the jet orifice. Pintles that covered 100 percent of the jet showed a strong deviation from the traditional interaction with no pintle. Relationships were also found between the angle, height, and penetration depth although none as ubiquitous as the jet coverage.

Liquid fuel injection is a critical mechanism for the deliverance of liquid fuel in contemporary aircraft propulsion combustion systems due to its outsized influence in providing optimal combustion conditions and improving overall aircraft efficiency and performance. Despite this, these liquid jet in crossflow (LJIC) systems are highly variable due to conditions in the jet and the surrounding airflow, leading to variability in performance behavior and inconsistency in fuel mixing and combustion efficiency. This has prompted the introduction of solid pintile obstructions of novel designs to provide a more flow-independent fuel injection scheme and decrease variability of the jet properties against a range of crossflow conditions. This thesis will examine the effects of a solid pintile obstruction on the behavior of an LJIC injection in a typical ramjet combustion configuration, with a focus on the face angle variations of these pintiles. Two pintiles, with face angles of 60° and 120°, will be tested against a no-pintile control configuration under a range of relevant operating conditions and observed under a novel method of 3D-imaging in the x-z plane view. The investigation is designed to understand the effects of these pintiles in the context of broad shifts in the momentum flux ratio and Weber number across a broad range of vitiated and non-vitiated environments. Results demonstrate the significance of the pintiles on the trajectory and performance of an LJIC injection. Building upon previous investigations on the influence of various pintile dimensions, the face angle was found to play a similarly critical role in the influence of the LJIC injection. Overall, the 120° wider face angle appears to be most optimal in enhancing crossflow interaction and promoting flow-independence compared to the 60° face angle. Future research on narrower and wider face angles and the relationship between the face angle and other design parameters could further improve LJIC injection performance and flow-independence.