Experimental study of mixing of directly injected fuel with air in an optically accessible engine using laser-induced fluorescence.

摘要

Most of today's automobiles burn petroleum fuels. A limited supply of these fuels requires that we pursue various avenues to conserve the existing quantities. One way that will help conserve these supplies is by increasing the efficiency of internal combustion engines. For our national economy, it is important to reduce pollution and the gases that influence global wanning. One way to obtain these goals is by improving the efficiency and by better understanding the mixing of the fuel and the air in an internal combustion engine. To help us understand this process, a suitable chemical tracer was added to the liquid fuel. Using a laser to excite this chemical resulted in fluorescence light emission that was quantified through an extensive in-cylinder calibration. This proved to be a good technique since this chemical showed little effect of oxygen quenching, which enabled a realistic engine experiment. In order to perform this type of study in an engine, one needs optical access to the combustion chamber. This was accomplished by constructing a single-cylinder, optically accessible engine. The construction of such a rig and performing a quantitative analysis of the fuel and air mixing are the foci of this work.