Enhanced Combustion of Fossil-Fuel Particles and Droplets in Oscillating Flow. Annual Technical Report, 1 September 1978-31 August 1979

摘要

The objective of this research is to determine the effect of oscillating flow on the rates of combustion of fossil fuel particles or droplets. Under certain conditions, an oscillatory (pulsating) flow may produce significantly increased rates of burning of fuel particles or droplets and thus provide more effective fuel utilization, with reduced excess air and improved combustion efficiency. The combustion intensity (energy released per unit volume) is known to be considerably higher in pulsating than in ordinary combustion chambers, so that for the same thermal power output, the chamber volume and cost can be significantly reduced. This would be an important advantage both for large powerplants and for those intended for special applications where space or weight are limited. Despite the technological advantages of pulsating combustion, the process is not well understood. The dependence of burning rate on the amplitude and frequency of the pulsating flow is not known; in fact, the literature contains limited and somewhat conflicting data on the magnitude of the effect of pulsations on burning rate. The present research was undertaken in order to determine the burning times of particles under conditions of controlled amplitude and frequency, and to develop theory to aid in interpretation of experimental data and to predict the effect of pulsations under other conditions. The apparatus built for the experimental work is described. Also a theory is developed and a solution obtained for limiting cases. (ERA citation 06:019051)