Abstract

Exact knowledge of the local temperature during the compression of air/fuel-mixtures in engines is crucial for evaluating modeling results of the ignition conditions and the flame development after ignition. Especially in ultra-lean burning modern engines using stratified load and exhaust gas recirculation inhomogeneous mixing takes place and causes inhomogeneous temperature distributions. Thus two-dimensional temperature imaging techniques have to be applied to provide the necessary information for model calculations. Temperature measurements in the compression stroke both before and after ignition have been performed in specially designed optically accessible engines using Rayleigh scattering 1. In more production-like engines, however, due to background scattering the use of Rayleigh scattering for temperature measurements is very limited.

© 1998 Optical Society of America