Abstract
Keywords:
DME, Spray development, Spray tip penetration, Spray cone angle
Abstract
This work was performed to investigate the macroscopic spray behaviors of DME injected through a common-rail injection system at similar conditions with the combustion chamber of diesel engine. In order to study the macroscopic spray characteristics of DME, the spray development of DME were analyzed in terms of spray tip penetration, spray cone angle, impingement timing and spray area. The process of spray development was visualized according to the injection duration, injection pressure and ambient pressure by using a spray visualization system composed of a Nd:YAG laser and an ICCD camera. A high pressure chamber with optical window was used to allow the simultaneous observation of the effect of ambient conditions on the spray characteristics of DME. It was also investigated the impingement timing and spray area in the case of in-cylinder condition and compare with that of diesel at the same injection conditions. It was revealed that the sprays of DME have shorter spray tip penetrations, wider spray cone angles and more rapid evaporating processes than those of diesel fuel. In the case of in-cylinder spray development, DME has longer impingement time on the wall and smaller spray area than diesel fuel.