The Statistical Theory of Turbulent Flames

摘要: The theory stemming from the statistical representation of turbulent flames is presented and developed, major aim being to describe basic processes in relatively simple flames. Starting conservation equations, with assumption low Mach number high Reynolds number, it shown that properties at any point flame can be determined transport equations for velocity U a set scalars : represents species mass fractions enthalpy. However, solution these initial conditions boundary appropriate prohibitively difficult. Statistical theories attempt behaviour averaged quantities terms quantities. This requires introduction closure approximations, but renders more readily soluble equations. A Reynolds-stress equation joint probability density function considered. use (p.d.f.) removes difficulties are otherwise encountered due non-linear functions (such as reaction rates). While p.d.f. provides useful description physics, its feasible only cases. As practical alternative, general method estimating first second moments: also considered therefore. Modelled stresses, dissipation rate, scalar moments fluxes discussed, including effects variations. physical interpretation given modelling unknown presented. It assumes statistically most likely distribution same moments. reactive or non-reactive scalars.