Turbulent premixed flame propagation in a cylindrical vessel

Abstract

An experimental and theoretical study of premixed flame propagation in a cylindrical vessel, containing turbulence inducing rings is described. The study was undertaken to provide further understanding of flame propagation and the generation of overpressure in explosions and to assess a mathematical model of explosions through comparison with detailed experimental data. Data gathered on flame location and shape, flow velocities, and overpressure during the course of an explosion are used to elucidate the dynamics of the various combustion processes occurring in the different chambers of the vessel. In particular, flame propagation through the vessel, until the flame front vents from the tube, is found to be substantially laminar, with significant overpressure only being generated in the later stages of the explosion due to rapid turbulent combustion in the shear layers and recirculation zones induced by the obstacles. Comparisons between measurements and numerical predictions obtained using an explicit, second-order accurate, finite-volume integration scheme, coupled to an adaptive grid algorithm, demonstrate that the mathematical model used provides a reasonable simulation of combustion within the vessel In particular, good qualitative agreement with observations is obtained for flame speed and shape, with rapid turbulent combustion being predicted with sufficient accuracy to yield reliable results for flow velocities and the overpressures generated.