Droplet evaporation plays a critical role in a wide range of industrial and technological
applications, from combustion engines to spray coating and refrigeration. While Eulerian-Lagrangian
models are widely used for predicting droplet behavior, they often assume a uniform
internal temperature, which may not be valid under high-temperature and high-pressure
conditions. This study compares the traditional lumped parameter model (LPM) with
a novel one-dimensional model employing a staggered grid (1D-SG) approach. Both models
are applied to water droplets in air over a broad range of initial diameters, relative
velocities, and ambient pressures and temperatures. The analysis evaluates deviations
in droplet lifetime and evaporation rate between the two approaches, emphasizing the
influence of Biot number, which is more sensitive to pressure than to temperature.
Results show that LPM remains accurate for small droplets and low convection conditions,
with deviations under 1 %. However, for larger droplets and enhanced convection, discrepancies
in evaporation rate and lifetime reach up to 6 % and 8 %, respectively. The findings
demonstrate that while LPM is computationally efficient, its applicability depends
on droplet size and flow conditions. The proposed 1D-SG model offers a more physically
consistent alternative when higher accuracy is required, providing guidance for model
selection in spray-related simulations.
