Accession Number : ADA184679

Title :   Ignition and Flame Propagation in Sprays.

Descriptive Note : Final rept. 1984-1987,

Corporate Author : CARNEGIE-MELLON UNIV PITTSBURGH PA DEPT OF MECHANICAL ENGINEERING

Personal Author(s) : Yao,S C ; Sirignano,W A ; Queiroz,M ; Rangel,R H

PDF Url : ADA184679

Report Date : 10 Jul 1987

Pagination or Media Count : 9

Abstract : A theoretical model of ignition and flame propagation in a spray consisting of a number of parallel droplet streams is presented. The analysis is based on a simplified representation of the fluid-mechanic aspects of the flow while focusing on the details of the heat transfer, vaporization, ignition, and flame propagation mechanisms across the various streams. In this simplified model, the fuel droplets are represented as discrete parallel streams which are continuous in the streamwise direction. With this configuration, steady state analyses are performed to investigate the influence of several parameters such as fuel volatility, droplet size, equivalence ratio, number of streams, and stream arrangement on heat transfer, vaporization, ignition and flame propagation mechanisms in the spray. An experimental exploration of the dynamic nature of the ignition and burning phenomenon and the thermal structure of a planar spray flame was performed. The influence of important spray parameters (e.g., fuel vapor concentration, and turbulence intensity) on the flame front motion was investigated, using sequential photographic information. Then the performance of micro-thermocouples for the measurement of gas-phase temperature in the presence of droplets was studied in a special gas flame as a means to analyze the thermal structure of the planar spray flame.

Descriptors :   *IGNITION, *FUEL SPRAYS, *FLAME PROPAGATION, DROPS, COMBUSTION, HEAT TRANSFER, VAPORIZATION, VOLATILITY, TEMPERATURE, STEADY STATE, MATHEMATICAL MODELS

Subject Categories : Combustion and Ignition

Distribution Statement : APPROVED FOR PUBLIC RELEASE