Improved Flamelet Modeling of Supersonic Combustion

Abstract

This paper has the objective of addressing a few basic issues pertaining to the use of the laminar flamelet method to model turbulence-combustion interactions in supersonic combustion. Specifically, this paper documents the way in which the use of Troe’s pressure-reaction-rate model affects the laminar flame solutions that are used in the generation of the flamelet library for supersonic combustion. For the opposed-jet model of nonpremixed flames, this study also investigates how the laminar-flamelet results obtained using the flamelet equations differ from those obtained from the canonical equations for opposed-jet flame (OJF). The differential results obtained for supersonic combustion predictions in two models of the scramjet isolator/combustor when pressure, in several formulations, is included as an independent variable of the flamelet table are also presented. Lastly, this study investigates the manner in which the use of various interpolations of the reaction progress variable from the S-curve affects turbulent supersonic combustion results. The overall goal of the various studies is to provide an improved flamelet modeling of supersonic combustion. Simulations based on linear progress variable interpolation coupled with the seven-level pressure field in the base flamelet library, using the OJF equations, appear to yield the best results.