ISSN Online: 2688-7231
ISBN Flash Drive: 978-1-56700-497-7
ISBN Online: 978-1-56700-496-0
Proceedings of the 25th National and 3rd International ISHMT-ASTFE Heat and Mass Transfer Conference (IHMTC-2019)
NUMERICAL INVESTIGATION OF DROPLET DEFORMATION AND BREAKUP IN ISOTHERMAL & EVAPORATING CONDITIONS
Abstract
In the present study, the volatile ethanol droplet deformation
and breakup phenomena were studied for an isothermal and
evaporating case. The parameters varied include Weber number
(We), droplet preheating temperature (Td), and surrounding temperature (T∞) in the range of 10-100, 300-350K and 725-755K. The commercial available ANSYS FLUENT v13.0 platform was utilized to perform all the numerical simulations. First, the Navier-Stokes equations in conjunction with the volume of fluid (VOF) equation were solved and validated with the benchmark
bubble rise case. The solver did not provide any evaporation
model in conjunction with the VOF model. Hence, a new evaporation model based on the kinetic theory of gases was
implemented by using a user-defined function (UDF) to evaluate
the mass transfer. The source term due to evaporation was
modeled in VOF, momentum, energy, and species equation. This
UDF was written and validated with the classical D2 law droplet evaporation case. After successful validations, the same solver settings were used to analyze the hydrodynamic and thermal behavior of droplet by plotting the various in-field parameters. The evaporation rate was found to increase with the increase in Weber number. Finally, the droplet breakup time was compared for isothermal with evaporation cases under various Td & T∞ conditions for a range of We.