Guillaume PELLETIER
DOI Number: XXX-YYY-ZZZ
Conference number: HiSST 2024-00121
Reactive Delayed Detached Eddy Simulations (DDES) were performed to investigate the effects of oscillatory hydrogen injection into a confined transverse supersonic flow of vitiated air. The corresponding experimental conditions were studied in the LAPCAT-II combustor, operating in the LAERTE facility at the ONERA Palaiseau Research Center. The core concept underlying this investigation revolves around the application of a fluidic oscillator, a device capable of inducing oscillatory motion in fluid flow, devoid of any mechanical components. In this context, oscillatory injection is harnessed to enhance the mixing efficiency within the combustor. Moreover, the study delves into another effect of the fluidic oscillator, the ability of sweeping injection to delay the onset of thermal choking within the combustor. This phenomenon has been identified as closely related to a specific structural interaction involving the boundary layer, shockwaves, and combustion processes. Improved mixing of fresh gases is demonstrated to mitigate this phenomenon, thus extending the operational envelope of the scramjet engine. The primary focus of this paper centers on the combustor’s response to various fluidic oscillators, encompassing a range of frequencies and sweeping angles. Comparative assessments of mixing and combustion efficiencies are conducted under constant equivalence ratios, and the maximum achievable equivalence ratio before encountering thermal choking is explored.