Thermodynamic Analysis of Entropy Generation Minimization in Thermally Dissipating Flow Over a Thin Needle Moving in a Parallel Free Stream of Two Newtonian Fluids

Abstract

This article is devoted to study sustainability of entropy generation in an incompressible thermal flow of Newtonian fluids over a thin needle that is moving in a parallel stream. Two types of Newtonian fluids (water and air) are considered in this work. The energy dissipation term is included in the energy equation. Here, it is presumed that u∞ (the free stream velocity) is in the positive axial direction (x-axis) and the motion of the thin needle is in the opposite or similar direction as the free stream velocity. The reduced self-similar governing equations are solved numerically with the aid of the shooting technique with the fourth-order-Runge-Kutta method. Using similarity transformations, it is possible to obtain the expression for dimensionless form of the volumetric entropy generation rate and the Bejan number. The effects of Prandtl number, Eckert number and dimensionless temperature parameter are discussed graphically in details for water and air taken as Newtonian fluids.

Effects of MHD and porosity on entropy generation in two incompressible Newtonian fluids over a thin needle in a parallel free stream

“…The physical configuration of the problem is given in Fig. 1 Under the above assumptions, the boundary layer equations in cylindrical coordinates are given by 18,19,[26][27][28][29] :…”

“…Khan et al . 26 recently discussed the entropy generation for two non-Newtonian fluids with first and second law analysis for a moving thin needle and obtained the solution by similarity transformation. From all, the above-discussed problems on thin needle focused on the heat transfer analysis and some recent on entropy generation.…”

“…Under the above assumptions, the boundary layer equations in cylindrical coordinates are given by 18 , 19 , 26 – 29 : …”

“…The entropy generation with heat transfer in the presence of Rosseland radiation for a boundary layer flow over a thin needle has been examined by Afridi et al 25 . Khan et al 26 recently discussed the entropy generation for two non-Newtonian fluids with first and second law analysis for a moving thin needle and obtained the solution by similarity transformation. From all, the above-discussed problems on thin needle focused on the heat transfer analysis and some recent on entropy generation.…”

Constructal Design of Elliptical Cylinders with Heat Generating for Entropy Generation Minimization

“…Many scholars [ 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 ] have performed extensive and in-depth researches on various processes [ 32 , 42 ], cycles [ 28 , 29 , 36 , 37 ], devices [ 30 , 31 , 35 , 40 ] and systems [ 44 , 45 , 46 ] based on EGM. Recently, various fluid flows such as Newtonian flow [ 93 ], carbon nanotube flow [ 94 ] and Darcy-Forchheimer nanofluid flow [ 95 ], microchannel heat sinks [ 96 ], heat exchangers [ 97 , 98 , 99 ], and so on, have been investigated with EGM. The conventional metrics, such as the heat transfer enhancement and pressure drop, evaluate convective heat transfer from the view point of the first law of thermodynamics, while the entropy generation analysis is from the view point of the second law of thermodynamics by uniformly characterizing the irreversibility of heat transfer and fluid friction.…”