Radiation Absorption by Droplets
This work is part of a collaboration with
Coordenação de Programas
de Pós-Graduação
em Engenharia (COPPE), Brazil
Abstract
Total hemispherical absorption distributions for n-decane and water droplets irradiated
by a blackbody under spherically symmetric conditions are used
in the calculation of transient droplet heating and vaporization. The gas model used is
based on the extended film theory.
Three liquid-phase models have been extended to include thermal radiation
absorption.
The results show that radiation absorption
can be as important as, or more important than, the choice of liquid-phase model.
Based on the effective-conductivity model, two dimensionless parameters
expressing the ratios of radiation absorption and gas-liquid heat transfer
to liquid conductive and convective heat transfer are defined.
It is shown that the first parameter
determines the droplet heating regime.
Over 200 numerical calculations using the
effective-conductivity model
and various initial and ambient conditions have been performed for water and n-decane droplets.
It is shown that the ratio of the two dimensionless parameters evaluated at the
initial time can be used to correlate and predict the radiation absorption
influence on the droplet lifetime.
All cases investigated correspond to the slow heating regime.
Under the conditions analyzed, the non-uniformity
of the radiation absorption has little effect on the overall droplet
heating and vaporization process.
Recent Publications
-
P. L. C. Lage and R. H. Rangel,
"Total Thermal Radiation Absorption by a Single Spherical Droplet,"
J. Thermophysics and Heat Transfer, 7, 101-109, 1993.
-
P. L. C. Lage and R. H. Rangel,
"Single Droplet Vaporization Including Thermal Radiation Absorption,"
J. Thermophysics and Heat Transfer, 7, 502-509, 1993.
-
P. L. C. Lage, C. M. Hackenberg, and R. H. Rangel,
"Non-Ideal Vaporization of Dilating Binary Droplets with Variable Properties,"
Int. J. Heat Mass Transfer, 36, No.15, 3731-3741, 1993.
-
P. L. C. Lage, C. M. Hackenberg, and R. H. Rangel,
"Non-ideal Vaporization of Dilating Binary Droplets with Radiation Absorption,"
Combustion and Flame, 101, 36-44, 1995.
Absorption Pattern
Go to the UCI MHT2F Lab Home page
Go to the UCI School of Engineering Home Page
Go to the UCI Home Page
Go to the UCI Office of Academic Computing Home Page