A Probability Density Function Model for the Calculation of Scramjet Flowfields

A proposal for the development of an advanced probability density function (PDF) model for the analysis of scramjet combustion is presented. The effects of turbulence chemistry interactions can have a pronounced effect on the ignition process, particularly for supersonic combustion applications where the residence time for fuel and air mixing is limited. Semi-empirical models have little hope for accurately predicting the ignition process due to the highly non-linear nature of the chemical source terms, therefore a computational methodology based on the physics of the flow is preferred. In Phase I, efforts will focus of 1) Development of a Monte Carlo based algorithm for solving the evolution PDF transport equation for supersonic combusting flows, 2) Comparison of the evolution PDF results with newly designed assumed PDF formulations, and 3) validation of the models with available experimental data for simple geometries. BENEFITS: This research effort encompasses state-Of-the-art turbulence-chemistry interaction models or scramjet applications. The proposed model, while emphasizing scramjet applications, can be applied to subsonic flows as well. The broad range of applicability of the model can be readily commercialized.