Transverse Detonation Waves in Near-Limit Detonations

The occurrence of reactive transverse waves in a narrow channel are studied in stoichiometric mixtures of methane and oxygen with 40-45% nitrogen dilution. Schlieren and CH* chemiluminescence measurements are obtained at MHz rates to study dynamic features of the detonation. Observations are made regarding the different ways that reactive and detonative transverse waves appear. A specific instance of transverse detonation is quantitatively analyzed and it is found that the shocked gas upstream of the transverse detonation builds up until consumed by the transverse detonation. The speeds of the transverse detonation and leading high-speed shock, itself a detonation, are measured to be moving at U_CJ and 1.2U_CJ, respectively.