Accession Number : ADA181726

Title :   Transient Spray combustion Computations.

Descriptive Note : Rept. for Oct 85-Oct 86,

Corporate Author : CALIFORNIA UNIV IRVINE DEPT OF MECHANICAL ENGINEERING

Personal Author(s) : Sirignano,William A.

Report Date : SEP 1986

Pagination or Media Count : 5

Abstract : Many practical combustion devices involves direct injection of liquid fuel into the combustion chamber, e.g., gas turbine engines, diesel engines, rockets and ramjet engines, and furnaces. Typically, the fuel is of sufficiently low volatility that vaporization is an important or controlling factor in the rate of combustion. It is desirable, therefore, to analyze the trajectories, heating, and vaporization of the large number of droplets in a fuel spray and to account for the exchange of mass, momentum, and energy between the liquid and gas phases in order to predict combustor performance, stability, and pollutant emission. A review is made of one-dimensional, unsteady and axisymmetric, unsteady spray combustion calculations. Proper formulation of the governing two-phase equations are discussed. Problems of ignition and flame propagation are examined. Since droplet lifetime is of the same order to magnitude as time for heat transport through the droplet, transient heating of the droplets is considered together with effects of internal droplet circulation due to shear forces on the droplet surface. Keywords: Sprays, Combustion, Ignition, Fuels, Droplets, Vaporization, Drag.

Descriptors :   *COMBUSTION, *COMBUSTION CHAMBERS, *FUELS, *FUEL SPRAYS, COMPUTATIONS, DIESEL ENGINES, DRAG, DROPS, EMISSION, ENGINES, EQUATIONS, EXCHANGE, FLAME PROPAGATION, CIRCULATION, FURNACES, GAS TURBINES, GASES, HEAT TRANSFER, HEATING, IGNITION, INJECTION, INTERNAL, LIQUIDS, MASS, MOMENTUM, PERFORMANCE(ENGINEERING), PHASE, POLLUTANTS, RAMJET ENGINES, RATES, ROCKETS, SPRAYS, SURFACES, TRAJECTORIES, TRANSIENTS, TWO PHASE FLOW, VAPORIZATION, VOLATILITY

Subject Categories : Combustion and Ignition
      Fuels

Distribution Statement : APPROVED FOR PUBLIC RELEASE