Measurements of fuel vapor concentration in a diesel spray by image analysis of a reconstructed hologram. 2nd report. Results at high-temperature and high-pressure atmosphere.

Abstract

Diesel spray in a high-temperature and high-pressure atmosphere was recorded by pulsed-laser holography. The schlieren and shadow images of the identical spray obtained from a reconstructed hologram were analyzed. The concentrations of the fuel vapor and droplets were estimated by using the photographic densities of these images. In the radial distribution of the fuel vapor, the concentration shows an anticlastic pattern and is maximal between the center and edge of the spray. As the time advances from the start of injection, the fuel vapor concentration begins to show an angle pattern, and is maximal at the center of the spray. In the axial distribution of the fuel vapor, the concentration averaged in the cross section of the spray is maximal at the axial location a little upstream from the tip of the spray.