Hydrogen fueled scramjet combustor with a wavy-wall double strut fuel injector

• Published in: Fuel (Guildford) 2021-11, Vol.304, p.121425, Article 121425
• Main Authors: Kummitha, Obula Reddy, Pandey, K.M.
• Format: Article
• Language: English
• Subjects: Combustion; Combustion chambers; Combustion efficiency; Computational fluid dynamics; Computer applications; Efficiency; Fuel injection; Injectors; Internal flow; Oblique shock waves; Reaction mechanisms; Scramjet; Shear mixing layer; Shock waves; Strut fuel injector; Supersonic aircraft; Supersonic combustion ramjet engines; Supersonic speed; Turbulence
• ISSN: 0016-2361; 1873-7153
• DOI: 10.1016/j.fuel.2021.121425

•Scramjet internal flow field in investigated for the basic and a novel strut fuel injector.•The turbulence development and its effect concerning strut design has been evaluated.•The effects of various shock waves and their reflections on simple and wavy wall double struts have been studied.•The rate of reaction was used to assess the combustion rate in relation to strut design.•It has been discovered that the wavy wall double strut have a significant effect on fuel and air mixing enhancement. The demand for the enhancement of scramjet performance is increasing worldwide due to its tremendous and upcoming applications. The major challenge in scramjet engines is the mixing of fuel and air and succeeding combustion at supersonic speed. In a scramjet combustor flow field, the development of high turbulence (flow disturbance), shear-mixing layer, and oblique shock waves are the key factors to magnify the mixing efficiency of fuel and air at the significantly less resident time of air in the combustion chamber. Based on these techniques, an innovative strut fuel injector with a wavy wall surface and double strut has been investigated for possible mixing enhancement of fuel and air. These results are compared with the basic single wedge strut available in the open literature to identify the performance improvement. The computational geometries are modeled with Reynolds-averaged Navier Stokes equations, SST k-ω model, and global one-step reaction mechanism. All the flow modeling has been solved with finite volume and a second ordered upwind discretization scheme. The evaluation of scramjet internal flow structure and numerical results found that the double strut with a wavy-wall shape improved the mixing efficiency and combustion phenomenon significantly. The mixing and combustion profiles reveal that wavy-wall double strut generates an early complete mixing within a distance of 0.17 m with increased mixing and combustion efficiency of 18% and 20%, respectively.