Evaporation and burning of a spherical fuel droplet in a uniform convective flowfield

Technical Report · Wed Jan 01 04:00:00 EST 1992

DOI:https://doi.org/10.2172/6915417· OSTI ID:6915417

Madooglu, K

An analytical/numerical model is developed for the evaporation and burning of a spherical fuel droplet in a subsonic crossflow. The external gaseous flowfield is represented using an approximate compressible potential-flow solution, while the internal flowfield of the droplet is represented by the classical Hill's spherical vortex. This allows a numerical solution for the external boundary layer, from which the droplet's effective drag coefficent, rate of mass loss, size, and the shape of the diffusion flame with infinitely fast chemical reaction kinetics are determined. Subsequently, the quasi-steady model with uniform liquid temperature is extended to examine the effects of the transient heating of the droplet interior. Time-dependent calculations are performed with updated droplet Reynolds numbers and updated surface temperatures. Comparisons of model predictions with experimental data are made. To examine the effects of finite-rate chemical reaction kinetics, a one-step formulation of the combustion mechanism is integrated into the gaseous boundary layer equations. Simplifying assumptions for the variation of gas properties commonly used in combustion calculations, are subjected to an examination as to their degree of accuracy. For this purpose, the droplet model is extended to account for the variation of gas properties with temperature and gas composition within the boundary layer. Comparisons are made between the predictions obtained from the different models developed in this study, as well as with existing experimental data.

• Research Organization: California Univ., Los Angeles, CA (United States)
• Sponsoring Organization: DOE; NASA; USDOE, Washington, DC (United States); National Aeronautics and Space Administration, Washington, DC (United States)
• DOE Contract Number: FG03-88ER13910
• OSTI ID: 6915417
• Report Number(s): DOE/ER/13910-T2; ON: DE93002223; CNN: NCC2-374
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400800* -- Combustion
Pyrolysis
& High-Temperature Chemistry
BOUNDARY LAYERS
CHEMICAL REACTION KINETICS
COMBUSTION KINETICS
CONVECTION
DATA
DIFFUSION
DROPLETS
ENERGY TRANSFER
EVAPORATION
FLAMES
FUELS
HEAT TRANSFER
INFORMATION
KINETICS
LAYERS
LIQUID FUELS
MASS TRANSFER
MATHEMATICAL MODELS
NUMERICAL DATA
PARTICLES
PHASE TRANSFORMATIONS
REACTION KINETICS
REYNOLDS NUMBER
THEORETICAL DATA