Physical and mathematical (system of differential equations in private
derivatives) models of heat and mass transfer were developed to investigate
the evaporation processes of water droplets and emulsions on its base moving
in high-temperature (more than 1000 K) gas flow. The model takes into account
a conductive and radiative heat transfer in water droplet and also a
convective, conductive and radiative heat exchange with high-temperature gas
area. Water vapors characteristic temperature and concentration in small
wall-adjacent area and trace of the droplet, numerical values of evaporation
velocities at different surface temperature, the characteristic time of
complete droplet evaporation were determined. Experiments for confidence
estimation of calculated integral characteristics of processes under
investigation - mass liquid evaporation velocities were conducted with use of
cross-correlation recording video equipment. Their satisfactory fit
(deviations of experimental and theoretical velocities were less than 15%)
was obtained. The influence of radiative heat and mass transfer mechanism on
characteristics of endothermal phase transformations in a wide temperature
variation range was established by comparison of obtained results of
numerical simulation with known theoretical data for ?diffusion? mechanisms
of water droplets and other liquids evaporation in gas.
On the Relationship between the Coherent Structures and Heat and Mass Transfer Mechanism near a Free Surface in a Fully Developed Turbulence.
