Mitchell D. Smooke

Solution of burner-stabilized premixed laminar flames by boundary value methods

A numerical technique has been developed for integrating the one-dimensional steady state premixed laminar flame equations. A global finite difference approach is used in which the nonlinear difference equations are solved by a damped-modified Newton method. An assumed temperature profile helps to generate a converged numerical solution on an initial coarse grid. Mesh points are inserted in regions where the solution profiles exhibit high gradient and high curvature activity. These features are discussed and illustrated in the paper, and the method is used to calculate the temperature and species profiles of several laboratory flames.

Toward a comprehensive chemical kinetic mechanism for the oxidation of acetylene: Comparison of model predictions with results from flame and shock tube experiments*

A chemical kinetic model for the oxidation of acetylene is presented. The model is usedto calculate flame speeds for adiabatic, freely propagating flames, composition profiles for lean and moderately rich burner-stabilized flames, and induction times and exponential growth constants for shock induced ignition. These results are then compared to the corresponding experimental results currently available. Rate coefficient information is derived predominantly from reaction-specific experiments. Since the comparisons made here are generally favorable, the kinetic model is consistent with a very large body of experimental, and in some cases theoretical, information. Important aspects of the reaction mechanism are discussed.

Implicit Methods in Combustion and Chemical Kinetics Modeling

Publisher Summary This chapter discusses that the purpose in modeling chemical kinetics is to predict and explain the evolution of chemical species in a reacting flow. There is an enormous payoff to be gained by understanding the complex chemical kinetics processes that govern the production and control of pollutants in combustion. The chapter describes the chemical kinetics equations that are stiff, and implicit numerical algorithms are needed for their solution. The solution of systems of chemical kinetics equations without spatial dependencies is accomplished routinely by the use of well-tested and documented software. The challenge for the future is to model the coupled effects of chemical kinetics and fluid transport. Chemical systems are usually characterized by the presence of widely disparate time scales. This is because some chemical species have reaction times that are extremely short compared with the reaction times of others. It also discusses the numerical solution of the large systems of nonlinear algebraic equations that are present in any implicit method.

ON THE USE OF ADAPTIVE GRIDS IN NUMERICALLY CALCULATING ADIABATIC FLAME SPEEDS

We investigate the effects of using adaptive and equi-spaced grids in an adiabatic flame speed calculation.

Numerical Solution of Burner-Stabilized Pre-Mixed Laminar Flames by an Efficient Boundary Value Method

A numerical technique has been developed for integrating the one-dimensional, steady-state, pre-mixed laminar flame equations. A global finite difference approach is used in which the nonlinear difference equations are solved by a damped-modified Newton method. An assumed temperature profile helps to generate a converged numerical solution on an initial coarse grid. Mesh points are inserted in regions where the solution profiles exhibit high gradient and high curvature activity. These features are discussed and. illustrated in the paper.