Abstract
A dual-wavelength laser absorption-scattering (LAS) technique was developed by use of the second harmonic (532nm) and the fourth harmonic (266nm) of a pulsed Nd: YAG laser as incident light and dimethylnaphthalene (DMN) as the test fuel. By applying this technique, imaging was made of DMN sprays injected into a high-temperature and high-pressure constant volume vessel by a single-hole nozzle and a common rail injection system for D.I. Diesel engine. The line-of-sight optical thickness of both fuel vapor and droplets in the sprays was obtained from the sprays images. The quantitative information of the distributions of the vapor concentration and droplets density was further deconvoluted using the onion-peeling model.
