METHODS FOR EXAMINING ANISOTROPIES IN EARLY COMBUSTION .1. MULTISCALEEXPERIMENTAL DETERMINATIONS

Experimental measures are developed for the description of anisotropic growth in the early stages of the flame kernel development in an oper ating spark ignition internal combustion engine. These measures are de velopments of the support area concept introduced by Bradley and Abdel -Gayed. By applying the technique of multi-scale analysis derived from texture analysis to such anisotropy measures it has shown to be possi ble to obtain time dependent information about the effect of the vario us local length scales in the processes that influence early flame gro wth. The analysis techniques employed are demonstrated to offer very w ide scope for characterising anisotropic time varying combustion and t he basis is laid for a formal development of this topic as presented i n the companion paper. An interesting observation is that for cycles o ther than partial combustions the largest length scale of process effe cting the flame kernel on tends to increase with time during the early flame growth.