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Journal of Polymer & Composites Original Research Open Access

Effect of Initial Temperature and Diameter of Ethanol Droplet on Evaporation Dynamics in Convective Air Medium

  1. Numan Siddique Mazumder Department of Mechanical Engineering, North Eastern, Regional Institute of Science and Technology, Nirjuli
  2. Pradip Lingfa Department of Mechanical Engineering, North Eastern, Regional Institute of Science and Technology, Nirjuli
  3. Asis Giri

Abstract

Ethanol is a suitable biofuel as it has fewer toxic emissions and higher-octane numbers. For spray combustion applications, the gas phase motion must be considered while numerically investigating the fundamental aspects of droplet evaporation and combustion processes. Hence, we have numerically simulated the evaporation dynamics of an isolated spherically shaped ethanol droplet under a forced convective air environment in the absence of gravity. The momentum transfer between two phases is captured by incorporating the Navier-Stokes equation into the spherical polar coordinate system. The governing equations of species, motion, and heat transfer are solved with the aid of the finite difference method. The variable blowing effect (Stefan flow), unsteady droplet heating, and non-unitary Lewis number are considered in the mathematical formulation. The Reynolds number is considered 100 at an ambient temperature of 600 K. The present work is validated by comparing the d2-curve of an ethanol droplet with the literature. A parametric study was performed to examine the effects of droplet initial diameter and temperature. The diameter is considered in the range of 0.2 mm to 1.0 mm, while the internal temperature is varied from 290 K to 325 K. The results reveal that droplets with a smaller diameter evaporate early, and the heat-up period is less compared to the bigger droplet. Moreover, a droplet with a higher internal temperature has a relatively shorter life span compared to one with a lower internal temperature. Also, the streamline, isotherm, and species concentration contour plots of the evaporating droplet have been shown.

Keywords

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