Methods for Examining Anisotropies in Early Combustion Part II: Theoretical Developments

ABSTRACT

This study reports some preliminary steps in the development of techniques for simplifying the problem of analysing spatially propagating reactions in anisotropic multi-phase systems. The target situation is combustion in a spark ignition petrol engine; nevertheless the method described has a much broader range of application.

Both present and future experimental techniques and C.A.D. methods concerned with spatially resolved combustion data are and will be faced with enormous complexity of detail. This is essentially due to the geometry and dimensionality of the problem of the propagation of in-cylinder combustion. However, many features of interest concern the fundamental structural properties of the burning air/fuel system, such as how far combustion has progressed, how a given burning region is linked to others, how robust are these connections with respect to flow field disturbance. These are the type of issues the formalism is best suited to address. The approach is mainly analytical and the combustion description is treated via a set of mathematically tractable special cases of increasing complexity. From these a general computational approach is proposed for real situations.

The background of this work is the recent introduction of a percolation description of combustion.