Numerical Simulation of Supersonic Nonpremixed Turbulent Combustion in a Scramjet Combustor Model

Abstract

Nonpremixed turbulent combustion is studied in situations relevant to those encountered in advanced airbreathing engines operating at high flight Mach number values. Accurate simulations would require modeling both finite rate chemical kinetics and molecular diffusion effects (mixing) as well as the complex compressible flowfield structure associated with the presence of multiple shock and expansion waves that significantly influence combustion. The chemical kinetics are modeled by using a Lagrangian framework for turbulent combustion that has been recently extended to reactive high-speed flows. The corresponding framework incorporates both finite rate kinetics and turbulent molecular mixing rates with minimal additional parameters. An efficient anisotropic mesh adaptation strategy is used to obtain a satisfactory description of both nonreactive and reactive compressible flowfields. The present study confirmed that the proposed approach provides a well-suited framework for future developments devoted to nonpremixed turbulent combustion modeling in high-speed flows. A detailed comparison with data gathered from an experimental study of a laboratory scramjet model indicated the validity of the approach.