10 - Optical diagnostics for direct injection gasoline engine research and development

Abstract

The capabilities and applications of optical diagnostics for engine research and development have grown dramatically since early applications were reported in the 1930s. They have long become a crucial component that enables the development of ever better internal combustion engines, making the transition from being esoteric research tools to becoming mainstream tools. A growing interest in developing direct injection engines of all sorts (spark-ignition and compression ignition) has triggered a flurry of developments in optical diagnostics that in turn were crucial in developing and improving new engine concepts. Optimized multiphase flow, stratified charge, partially premixed combustion, spray impingement, soot formation, and other effects that were not important in carbureted and port-fuel-injection gasoline engines have become critical to the success of direct injection engines. Techniques and their applications for measurements of important parameters such as fuel concentration, flow, temperature, and pollutants are presented in this chapter.