Time-Resolved Mixture Concentration Distribution Measurement of Diesel Spray

-Development of High Speed Tracer LAS Technique-

Abstract

The Laser Absorption Scattering(LAS) technique is used to investigate the fuel mixture formation process．This method is able to measure the liquid and vapor phase concentration distribution in the diesel spray．The conventional LAS method which adapts on Nd:YAG laser with the 266 and 532nm wavelength has a limitation that，only one image of the spray in one injection event can be captured at a given timing．This method requires many different injection events in order to acquire a set of sequential images．To solve this limitation，a continuous laser (532nm) and pulsed LED (266nm) were used as the light sources for the high-speed LAS imaging．To capture the time-resolved image，two high speed video camera were used．One high speed camera detected the 532nm light while the other was coupled with the image intensifier to detect the 266nm light．In addition to that，the results are compared with conventional single shot LAS results．