Spray detonation in a well-characterized homogeneous mixture

An investigation of two-phase (spray) detonation, and of the parameters that control its behavior, was performed. The goals of this study were to utilize a practical spray---with relatively small droplets and a polydisperse droplet diameter distribution---and to have a well-characterized and controlled homogeneous initial mixture state. To this end, a unique mixing strategy---the opposed-injection configuration---was developed. This configuration employs a sequence of "modules", each with two injectors firing directly into one another, to control mixture characteristics and to achieve a uniform mixture throughout a large volume. The mixture created in this manner was found to be relatively homogeneous within limitations set by the preferential concentration of Stokes number unity droplets by gas-phase turbulence.; The two-phase mixture state was characterized using a number of different methods. Laser diffraction (Malvern) was used to measure the mean diameter of the droplet diameter distributions. Mie scattering was used to image the mixture throughout its development. Statistical analysis of ensembles of these images was used to ascertain mixture homogeneity. Laser extinction measurements were used to estimate the mass of liquid suspended in the gas phase at the time of detonation.; Detonation experiments were performed using a range of parameters. The equivalence ratio, the concentration of O2 and N2, and the Sauter mean diameter of the droplet distribution were varied. In addition, the fraction of fuel present in the gas phase and in the liquid phase at the time of detonation was varied. This was achieved using a dual-fuel scheme utilizing both propane (gas) and decane (liquid) as fuel. The velocity of each detonation was monitored at forty locations and used to generate "velocity profiles" which were then used to characterize detonation behavior.; A one-dimensional model was prepared to supplement the experimental results. This model permitted "what if?" analyses to be performed. Reaction rate, chemical induction time, evaporation rate, and droplet distribution shape---parameters that cannot be readily controlled experimentally---were varied and their effect on detonation velocity ascertained. The conclusions drawn from the experimental and numerical results are presented with supporting data.