Spray drop-size distributions across a free shear-layer flow

In the present study we analyze the evaporation and coalescence of fuel droplets suspended in one of the streams in a shear-layer flow. Similarity solutions are presented for the evolution in drop-size distributions across the shear-layer, and the effects of various coalescence rates on the profiles of the SMD (Sauter Mean Diameter) and fuel-vapor concentrations are examined. The investigation presented here has important ramifications for many engineering applications in which sprays are involved. For example, in spray combustion research it is important to analyze the evaporation of the droplets across the shear-layer and the effect of the characteristics of the spray on the spread of fuel-vapors into the co-flowing air stream since the fuel-vapor local concentrations, together with other governing parameters, eventually determine the location and structure of the spray diffusion flame that will result upon ignition. These issues are also discussed in the present work. MINERALOGY IN AIRBORNE DUST E. Azmon* and Z. Y. Offer+ *Department of Geology and Mineralogy, Ben-Gurion University of the Negev, Beer-Sheva, Israel ‘Jacob Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Sede Boquer, Israel The combined utilization of petrographic microscopy and scanning electron microscopy is a technique developed for the identification of heavy mineral grains that are finer than 30 pm in diameter. The same technique was used successfully in identification of airborne dust particles collected in the Negev Desert. Thus crystalline grains of kaolinite, quartz, apatite and others were identified in the dust and were clearly differentiated from organic small particles. 1019