Understanding Turbulent Flows and Combustion in Scramjets and Hypersonic Vehicles: A Comprehensive Review

Pradyumna Rangnath Surwase

Abstract: This literature review examines the physics and modeling of turbulent flows in scramjets and hypersonic vehicles, with a focus on the Navier - Stokes equations and the conditions necessary for accurate simulations. It covers the Boltzmann equations for non - equilibrium flows, the significance of boundary layer thickness, and the application of Direct Monte Carlo Simulation, along with other turbulence models such as the Spalart - Allmaras and SST k - ? models. The review also explores the concept of detonation in scramjets, various fuel injection strategies, combustion processes, and heat transfer in the context of hypersonic flows. Additionally, it addresses challenges associated with scramjet engines, including temperature gradients, oscillatory combustion, and shock waves. The paper highlights the complexities involved in modeling and simulating turbulent flows in scramjets and hypersonic vehicles, underscoring the need for ongoing research and advancements in this field.

Keywords: Scramjet, detonation, hypersonics, rarefied gas dynamics, fuel injectors, combustion, Knudsen number, re - entry vehicle