Experimental investigation on the DDT run-up distance and propagation characteristics of detonation wave in a millimeter-scale spiral channel filled with hydrogen-air mixture

Abstract

An experimental study on flame acceleration (FA) of hydrogen–air premixed gas in a millimeter-scale Archimedean spiral channel is presented in this paper. Experiments were performed in a transparent rectangular cross-section channel and the flames were recorded by high-speed photography. The flame propagation characteristics under different equivalent ratios and different initial pressures was compared. Results show that the minimum LDDT (DDT run-up distance) are obtained at stoichiometric ratio. With increasing the initial pressure, the smaller LDDT is observed. Moreover, Due to the combined effects of the chemical reaction, wall dissipation, and geometric curvature effects, the flame velocity showed a significant oscillation pattern. Decreasing initial pressure and keeping away from the stoichiometric ratio increasingly favour the low velocity mode. The current conclusions of this study are helpful to the development of new pre-detonator and evaluate the danger of hydrogen detonation in micro systems.