Deflagration to detonation transitions in hexane and heptane mixtures with oxygen

TLDR: In this paper, a detonation transition was measured by timing the change in light intensity of the reaction front and the measurement was supplemented by pressure detected by transducers along the tube.

Abstract: Mixtures of hexane with oxygen and heptane with oxygen have been initiated in a detonation tube by a controlled electric spark. The equivalence ratios investigated were 0.54 to 1.74 for hexane and 1 to 1.9 for heptane. Initial pressures investigated were 100–650 torr for hexane and 95–250 for heptane. Time and distance of deflagration to detonation transition (DDT) were measured as a function of the concentrations, initial pressures and spark energy. The occurrence of DDt was measured by timing the change in light intensity of the reaction front. The measurement was supplemented by pressure detected by transducers along the tube. Good agreement has been found between experiments and CJ calculations.