Open Active Contour Model For Front Tracking Of Detonation Waves

Abstract

This paper presents an image processing framework for tracking the front of the detonation wave from a sequence of images. The images are captured by high speed camera during a laboratory gas explosion experiment. By tracking the fronts in two or three consecutive frames, it is possible to calculate the thermodynamic properties like velocity and pressure along the entire wave front. Alternatively, these calculations are limited to measurements recorded by sensors at some fixed, locations. An active contour model having Gradient Vector Flow (GVF) as an external force field is used to track the wave front in each image. The structure and the properties of detonations in combustion physics has been the point of interest since early 80’s. In the present paper, detonation is studied in the stratified layer of combustible gas above a non-reacting layer of air. The recorded images are digitally processed, and the local velocities are calculated based on the tracked fronts. The calculated velocities are then used to estimate the pressure ahead of the wave front with the help of the normal shock relations. The estimated pressure is compared with the measured values from pressure transducers mounted on the top and bottom of the experiment tube.