Effect of Ramp Leading Edge Blunt on the Performance of a Mach-4 Scramjet Intake

This numerical study is primarily focused on the performance enhancement of scramjet intake model by introducing blunt in the leading edge of the ramp instead of a sharp leading edge. A scramjet intake model developed by Saied Emami et al. (1995)[1] is adopted as baseline model in this study. Ansys Fluent 18 is used to perform numerical simulations to study the flow through baseline model and modified models. A comparison is made between the available pressure data in the existing literature and in the present numerical study to validate the computational methodology followed. This study involves with scramjet intake models having ramp leading edge blunt radii of 0.0025 in., 0.005 in., 0.0075 in., and 0.01 in. The changes in the velocity boundary layer and thermal boundary are studied. A little reduction in the flow separation is observed from the wall shear stress plot. The shock pattern in the isolator section improves and is seen clearly from numerical schlieren. Considerable improvement in the total pressure recovery is achieved. The Mach number at the isolator exit has also increased due to the ramp leading edge blunt.