Thermodynamic second law analysis for a gravity-driven variable viscosity liquid film along an inclined heated plate with convective cooling

Abstract

The inherent irreversibility and thermal stability in a gravity-driven temperature-dependent variable viscosity thin liquid film along an inclined heated plate with convective cooling is investigated. In this study, both the isothermal and isoflux heating of the plate are considered. The free surface of the liquid film is assumed to exchange heat with the surroundings following Newton's cooling law and the fluid viscosity model varies as an inverse linear function of the temperature. Analytical solutions are constructed for the governing boundaryvalue problem, and important properties of velocity and temperature fields such as thermal stability criterion are obtained. Expressions for volumetric entropy generation numbers, irreversibility distribution ratio, and the Bejan number in the flow field are also obtained and discussed quantitatively.

Entropy Generation Analysis of Open Parallel Microchannels Embedded Within a Permeable Continuous Moving Surface: Application to Magnetohydrodynamics (MHD)

“…In this study, the Bejan number is defined as the ratio of heat transfer irreversibility to total irreversibility due to heat transfer, fluid friction and magnetic field for the laminar MHD boundary layer flow. Mathematically, Bejan number is given as [45,46] (30) where ĭ is the irreversibility distribution ratio which is defined as: ility irreversib fer Heat trans ility irreversib field Magnetic ility irreversib friction Fluid ) (31) As the Bejan number ranges from 0 to 1, it approaches zero when the entropy generation due to the combined effects of fluid friction and magnetic field is dominant. Similarly, Be > 0.5 indicates that the irreversibility due to heat transfer dominates, with Be = 1 as the limit at which the irreversibility is solely due to heat transfer [47].…”

The Marangoni convection induced by acetone desorption from the falling soap film

“…It is well known that the Marangoni convection has an important influence on the engineering application related to the mass and heat transfer [1][2][3]. Meanwhile, as a strong nonlinear phenomenon with the coupling motion-convective diffusion transfer, it is also of high interest for the fundamental theory research [4][5][6].…”

Thermodynamical Analysis of the Flow and Heat Transfer over a Static and a Moving Wedge

“…Makinde [11] discussed the irreversibility effects in variable viscosity channel flow with convective cooling at the walls. Second law analysis for a gravity driven variable viscosity liquid film along an inclined heated plate with convective cooling was made by Makinde [12]. Révèillere and Baytaş [13] studied entropy generation in laminar boundary layer flow over an isothermal permeable flat surface.…”