Heat Release Rate Analysis of Ultrasonically Driven Pintile Injectors

This study investigates the efficacy of a novel pintle injector design utilizing ultrasonic excitation to enhance the combustion process in a liquid jet in crossflow (LJIC) configuration. Pintiles, or solid obstructions in the flow path, have already been shown to be a promising step towards flow independence for these injection systems, however the additional component of vibration to assist with fuel breakup is considered here. Three metrics for determining the injector’s efficacy in enhancing combustion equivalence ratio uniformity, heat release rates, and flame stability. A highspeed camera equipped with CH* and C2* lens filters allow for flame visualization and combustion. As well as qualitative analysis on the fuel distribution, flame location, and flame shape. From the research performed here, the equivalence ratio was shown to be less uniform when ultrasonically excited, however had the added benefit of deeper penetration, the regions of the flame with highest CH* intensities grew larger and brighter with the addition of ultrasonic excitation, and the flame stability and effective flame speed improved when vibrations were active.