Numerical methods in laminar flame propagation. A GAMM workshop.. Questo articolo non è disponibile.Numerical methods in laminar flame propagation. A GAMM workshop.

This volume collects the results of a workshop held at Aachen, West-Germany, Oct. 12 - Oct. 14, 1981. The purpose in bringing together scientists actively working in the field of numerical methods in flame propagation was two-fold: 1. To confront them with recent results obtained by large ac­ tivation-energy asymptotics and to check these numerically. 2. To compare different numerical codes and different trans­ port models for flat flame calculations with complex che­ mistry. Two test problems were formulated by the editors to meet these objectives. Test problem A was an unsteady propagating flat flame with one-step chemistry and Lewis number different from unity while test problem B was the steady, stoichiometric hy­ drogen-air flame with prescribed complex chemistry. The parti­ cipants were asked to solve one or both test problems and to present recent work of their own choice at the meeting. The results of the numerical calculations of test problem A are challenging just as much for scientists employing numerical me­ thods as for those devoted to large activation-energy asympto­ tics: Satisfactory agreement between the five different groups were obtained only for two out of six cases, those with Lewis number Le equal to one. The very strong oscillations that oc­ cur at Le = 2 and a nondimensional activation energy of 20 were accurately resolved only by one group. This case is par­ ticular interesting because the asymptotic theory so far pre­ dicts instability but not oscillations.

Discussion of Test Problem A.- Activation-Energy Asymptotics of the Plane Premixed Flame.- Theoretical Implications of Nonequal Diffusivities of Heat and Matter on the Stability of a Plane Premixed Flame.- The Effect of Lewis Number Greater than One on an Unsteady Propagating Flame with One-step Chemistry.- Discussion of Test Problem B.- On the Use of Adaptive Grids in Numerically Calculating Adiabatic Flame Speeds.- Results of a Study of Several Trans port Algorithms for Premixed, Laminar Steady-State Flames.- Influence of Transport Models and Boundary Conditions on Flame Structure.- Numerical Solution of Burner-Stabilized Premixed Laminar Flames by an Efficient Boundary Value Method.- Toward the Formulation of a Global Local Equilibrium Kinetics Model for Laminar Hydrocarbon Flames.- Time-Dependent Simulation of Flames in Hydrogen-Oxygen-Nitrogen Mixtures.- Mechanism of Flame Propagation in Hydrogen-Air and Methane-Air Systems.- Flames near Rich Flammability Limits, with Particular Reference to the Hydrogen-Air and Similar Systems.- Experimental Investigation of Internal Combustion of Various Fuels.