Application of Laser Diagnostics to an Injected Engine

Measurements taken in a special, single cylinder, direct injection stratified-charge engine are presented. The optical measurement techniques employed include continuous-wave laser Raman spectroscopy for fuel and air concentrations, pulsed laser Raman spectroscopy for density fluctuations, high-speed cinematography for flow visualization, and laser Doppler velocimetry for velocities and turbulence intensities. More conventional data on cylinder pressure, power, and emissions levels are also given. The purpose of the study is to demonstrate the types of detailed measurements that are now possible within an engine cylinder.