Seung-Min JEONG, Jae-Eun KIM, Jeong-Yeol CHOI
DOI Number: 10.60853/07a4-dk14
Conference number: HiSST-2024-00350
This study numerically investigated the reactive flow dynamics of a laboratory-scale gaseous hydrogenfueled scramjet combustor depending on a number of injectors. The main goal of the present study is not only to investigate a flame structure and combustion dynamics by changing fueling schemes but also to reveal the effect of injector schemes on combustion performance. A numerical simulation was performed using an improved delayed detached eddy turbulent model (IDDES) and Jachimowski’s hydrogen-air reaction mechanism. The simulation utilized high-order accuracy-based numerical schemes to ensure high-resolution and fidelity results. For a quantitative comparison of the effect of injector schemes, single and multi-injectors with five equivalence ratio cases in one set were considered. Numerical results found an intricate coupled fluid-combustion dynamics and its transition depending on the number of injectors and global equivalence ratio. Comprehensive numerical results showed completely different fluid-combustion dynamics by injector schemes. Specifically, a counter-rotating vortex pair of the multi-injector case was not maintained, resulting in decreased fuel/air mixing and combustion. Due to this phenomenon induced by an interaction between the injector-injector and injector-wall surface, it was revealed that the combustion efficiency is significantly reduced for the multi-injector compared to the single-injector under the same global equivalence ratio. These findings indicated that increasing the number of injectors cannot guarantee an increase in the mixing and combustion performance of a scramjet combustor.