Simultaneous measurement of three-dimensional flame contour and velocity field for characterizing the flickering motion of a dilute hydrogen flame

Abstract

In this paper, an experimental method for simultaneous measurement of three-dimensional flame contour and velocity field is described for characterizing the flickering motion of a dilute hydrogen flame. The three-dimensional flame contour is measured by three CCD cameras around the flame with a digital-image reconstruction technique, while the velocity field is measured simultaneously by a planar PIV technique, which is supported by flow visualization with a reactive Mie scattering method. The visualization result shows that the flame structure consists of an inner flame, where the tracers follow the fuel flow, and an outer surrounding flame, where the diffused fuel reacts with oxidants. It is also found that the velocity field varies periodically during the flickering motion of the flame, which is clearly observed near the top of the flame, oscillating vertically with a phase of the velocity field. These results suggest the usefulness of the present experimental technique.