Numerical simulation of reactive flows through two-dimensional burners

Dissertation research is directed towards development of an efficient numerical procedure for solving 2-D chemically reacting fluid flows. The conservative form of the full compressible Navier-Stokes equations for a multi-component chemically reacting fluid flow is solved. Chemical reactions are described by a detailed finite-rate chemistry. A real gas thermodynamic model is employed and allowances are made for variable transport properties.;The numerical model has been used to obtain a detailed understanding of laminar diffusion flames obtained above 2-D methane/air burners. It is observed that the structure and properties of laminar diffusion flames is considerably different from those obtained from the well known Burke-Schumann analysis.;Considerable emphasis has been laid on the leading edge portion of a diffusion flame referred to as the leading edge flame (LEF). Near the initial point of fuel-oxidizer contact, interdiffusion occurs faster than reaction, and a premixed flow develops. The premixed flow experiences an induction period followed by rapid heat release. The region of rapid heat release is called the LEF. The LEF is limited by the kinetics of the fuel and the oxidizer, whereas the rest of the diffusion flame is diffusion limited. The leading edge flame serves as a flame holding site for the rest of the diffusion flame. Preliminary results indicate that the LEF is unique, because it shows a considerably higher concentration of intermediate species, as compared to the rest of the diffusion flame, indicating high rate of reaction. It is also observed that the leading edge portion of a diffusion flame shows the maximum rate of heat release per unit volume. This coupled with the fact that the LEF is located closest to the burner surface makes it mainly responsible for the heat transfer back to the burner surface.;Parametric studies that determine the effects of inflow velocity, pressure and concentrations of the incoming gases on the location and properties of the LEF have been completed.