Evidence of Pressure Build-up in H_2-Air Fast Flames for Deflagration-to-Detonation

摘要

To begin uncovering the unknown mechanisms driving the Deflagration-to-Detonation Transition in largely unexplored environments, such as unbounded systems, a thorough characterization of fast flame acceleration in highly turbulent flow fields must be performed. Fast flames accelerating to detonation generate a complex flow field of highly turbulent and compressible reactants. These regimes have been probed using computational simulations, but require further experimental investigation and validation. The focus of the present work is to examine the intricate pressure dynamics that contribute to producing the conditions for detonation onset. Using a Turbulent Shock Tube with multiple configurations and optical access, schlieren imagery allows focused observation of the propagating flame behavior. High resolution pressure transducers capture highly transient events and identify pressure profiles to aid in identifying intricate compressibility effects in fast turbulent flame propagation. The work ultimately demonstrates a pressure build-up that is produced by a high level, fast flame acceleration.