Technical Report of National Aerospace Laboratory. A Computer Model for theSimulation of Turbulent Reacting Flow in a Jet Assisted Ram Combustor

摘要

A computer code for the simulation of the turbulent reacting flow in a jetassisted ram combustor is developed. Favre averaged Continuity and Navier-Stokes equations, equations for a low Reynolds number k-epsilon model and equations for mixture fraction and its variance are solved to simulate the turbulent reacting flow. A Stretched Laminar Flamelet Model (SLFM) in the mixture fraction space is used to simulate the combustion of Hydrogen and Air using a 28-step reaction mechanism with 10 species. The SLFM is coupled to the turbulent flow through density which is calculated using an assumed Beta-shaped probability distribution function for mixture fraction and a Log-normal probability distribution function for the scalar dissipation. All other mass averaged thermo-chemical variables are computed off-line after a converged solution has been achieved. Solution of the continuity equation and the three momentum equations is achieved using the SIMPLER algorithm. The linearized system of equations for each variable is solved sequentially using a Incomplete Lower Upper pre-conditioned conjugate gradient method. Simulation results showing the recirculation zones, distribution of species and temperature are presented.