Study on the Development Mechanism of Detonation Wave for the Hydrogen-Oxygen Mixture in a Shock Tube

This paper mainly focuses on the experimental investigation of the gaseous detonation wave build-up mechanism for hydrogen-oxygen mixture in shock tube. Five pressure sensors were used to record the pressures and a high-speed camera was used to capture velocities of flame, shock, or detonation wave. The high-speed camera records the transformation of flame, shock in the ignition phase and the attenuation of detonation wave. The experimental results show that the diagnostic system can effectively measure the DDT. The images of flame propagation show that the flame front is curving and dispersive. It is found that the interaction of shock and turbulent flame is a dominant factor for the onset of explosion. In the smooth tube, experiments indicate that the intensity of shock wave continually increases due to the acceleration of flame. The local explosion occurs in the reaction zone when the intensity of shock wave arrives at a critical pressure pc when some hot spots form in the local explosion centers. At that time, an unsteady detonation wave is formed immediately, and after a period of the propagation or attenuation process, it eventually evolves into a steady detonation wave.