Irreversibility Analysis for Nonlinear Flow Models with Thermal and Solutal Transportation

Abstract

Nanotechnology is useful for applications involving crack-resistance paint, thermal transport, engine cooling, heat exchangers, enhance-oil recovery, nuclear reactor cooling, transparent sunscreen, microelectronics, paper production, thermal power plants and architecture and many others. Numerous researchers have focused attention to discuss nanofluid flow behaviors. It is due to its innovance in numerous engineering, biomedical, industrials, biological science, and many other fields. Moreover for higher thermal conductance, the nanoparticles of nano-size (1-100 nm) have been inserted in conventional working materials. Numerous analyses have been carried out about nanomaterials up till now. However, hybrid nanomaterial is a new type of nanoliquid having keen attention to the modern nanotechnology processes investigations. Hybrid nanofluid is a new type of nanoliquid which works for heat enhancement in various applications with improved performance. Hybrid nanoliquid is the nanoliquid which is made of hybridization of two or more different kinds of nanoparticles. These materials combine physical and chemical properties of numerous fluid instantly. Entropy generation is a measurement of dissipated thermal energy and degradation of thermal system performance. Dissipated thermal energy is not used for any significant work. Thermodynamics second law states that total entropy of system cannot decreases for any isolated system and persists constant for any reversible processes while for irreversible process it always progresses, and consequently total entropy of closed system increases. Irreversible action containing Joule heating, radiation, viscosity of fluid, chemical reaction, diffusion and friction among solid surface in the system are important for entropy production. To make the equipment more significant the entropy production is minimized. It is useful in microchannels, chillers, reactors and curved pipes. Entropy generation minimization at present is a hot topic in engineering and thermal sciences. This is used in different fields including solar energy, heat transfer, conversion refrigeration and designs etc. It is a well-recognized fact that entropy production has an important role to reduce essential sources of thermal energy in any thermodynamical system. Heat transport mechanism has gained considerable attention of the researchers during the last few years. It is due to various applications in different fields like engineering, industry, pharmaceutical and coolant in machining, manufacturing etc. In fact, the researchers and scientists have focused their attention to increase the performance of numerous equipment’s by increasing thermal transportation rate and in achieving a good product with anticipated characteristics through rate of cooling/ heating. The combined influences of solutal and thermal transport are further efficient in different natural, pharmaceutical, medical, industrial, climate control, geophysical and engineering fields. Such phenomena comprise thermal insulation, environmental pollution, formation and distribution of fog, geothermal reservoirs, combustion, moisture over agricultural fields, damaging of crops due to freezing, enhanced oil recovery, petroleum reservoirs turbine systems, drying of porous solids, modeling of resin transfer nuclear reactions and many others. Motivated by such facts, this thesis communicates the entropy optimized nonlinear flow with solutal and thermal transport rate. This thesis is structured as follows. Chapter one includes literature review, some basic definitions and laws Material of this chapter is existing in literature. Chapter two explores the study of entropy optimized hydromagnetic flow of nanomaterial by a stretchable surface. Flow in porous space is scrutinized by Darcy-Forchheimer expression. Mathematical modeling for entropy generation regarding radiative flow is computed. Here silver (Ag) and gold (Au) are suspended in sodium alginate ((C₆H₇NaO₆)n) to make two different types of nanofluids (Ag/(C₆H₇NaO₆)n) and Au/(C₆H₇NaO₆)n). Influence of radiation, heat generation, viscous dissipation and Ohmic heating are addressed. The obtained dimensionless systems are computed through numerical scheme (ND-solve technique). The results of this chapter are published in Journal of Petroleum Science and Engineering (J. Pet. Sci. Eng.), 217 (2022) https://doi.org/10.1016/j.petrol.2022.110864. Chapter three discusses the entropy optimized flow of ternary (TiO₂+Fe₂O₃+SiO₂/WEG) nanofluid. Flow generation by an exponentially stretching surface is taken. Titanium dioxide (TiO₂), ferric oxide (Fe₂O₃) and silicon dioxide (SiO₂) are used as nanoparticles. Mixture of water (H₂O) and ethylene glycol (C₂H₆O₂) is employed as base liquid. Radiation, dissipation and Ohmic heating in thermal expression are accounted. Thermodynamics second law is implemented to describe the entropy analysis. Nonlinear partial differential systems are reduced to dimensionless form through non-similarity transformations. ND-solve technique leads to numerical solution. Interpretation of solution is arranged. The outcomes of this chapter are published in Energy Reports (Energy Rep.), 8 (2022) 9997-10005 https://doi.org/10.1016/j.egyr.2022.07.149. Chapter four analyzes the non-similarity solution for chemical reactive magnetohydrodynamic flow of nanofluid with entropy generation. Flow saturates porous medium Flow by an exponentially surface is taken. Radiation, heat source, magnetic force, and dissipation are taken into account. Thermophoresis and random diffusion behaviors have been also addressed. Dimensionless nonlinear system is solved by local non-similarity via the ND-solve technique. Graphical features for entropy rate, fluid flow, concentration and thermal field versus pertinent variables have been addressed. The related observations of this chapter are published in Journal of Computational Design and Engineering, 9 (2022) 1756–1764, https://doi.org/10.1093/jcde/qwac080. Chapter five scrutinizes MHD Reiner-Rivlin fluid flow over stretching sheet with radiation and dissipation. The main objective here is to address such flow in presence of Ohmic heating and Soret and Dufour effects. Besides these aspects the first order chemical reaction is accounted. To examine the thermodynamical system performance the entropy optimization is addressed. Non linear dimensionless systems are developed through suitable transformations. Non-dimensional differential systems have been computed by ND-solve technique. The material of this chapter is published in Int. Commun. Heat Mass Transf., 137 (2022) https://doi.org/10.1016/j.icheatmasstransfer.2022.106297. Chapter six addresses entropy generation in convective hydromagnetic flow of Reiner-Rivlin liquid by stretching sheet. Thermal expression is deliberated with radiation, Ohmic heating, and dissipation. Physical characteristics of Buongiorno model for nanofluid are discussed. Thermodynamics' second law is discussed for entropy minimization characteristics. First-order chemical reaction is scrutinized. Non-dimensional differential systems are developed by appropriate variables. The obtained dimensionless equations are numerically computed by Newton's built-in shooting method. The outcomes of this chapter are published in Alexandria Engineering Journal, 66 (2023) 257-268 https://doi.org/10.1016/j.aej.2022.11.027. Chapter seven is the extension of chapter six for bioconvection, linear thermal radiation and gyrotactic microorganism. The main theme here is to discuss the entropy generation and solutal and thermal transport rates. The computations of nonlinear systems are obtained by ND-solve technique. The results of this chapter are published in Alexandria Engineering Journal, 79 (2023) 81-92 https://doi.org/10.1016/j.aej.2023.07.069. Chapter eight is the extension of chapter six for linear heat flux and entropy generation in terms of homogeneous and heterogeneous chemical reactions and viscous dissipation. Furthermore, the convective condition is considered. Nonlinear ordinary systems is numerically solved by shooting technique The results of this chapter are published in Chaos, Solitons & Fractals, 171 (2023) https://doi.org/10.1016/j.chaos.2023.113424. Chapter nine explores the entropy rate in magnetohydrodynamic flow of Reiner-Rivlin liquid over stretchable sheet. Variable thermophysical characteristics are considered. Solutal and thermal transportation characteristics are studied by Cattaneo-Christov flux models. Entropy rate is discussed. Governing expressions are reduced to non-dimensional expressions by adequate variables. The obtained non-linear dimensionless systems are analytically computed for convergent solution through Optimal homotopy analysis method (OHAM). The related observations of this chapter are published Alexandria Engineering Journal, 72 (2023) 67-82 https://doi.org/10.1016/j.aej.2023.03.079. Chapter ten is the extension of chapter nine in terms of constant thermophysical characteristics, mixed convection, Brownian and thermophoresis diffusions and viscous dissipation. Here main theme is to discuss the thermal and solutal transport characteristics employing modified diffusive flux theory. Resultant non-dimensional ordinary expressions are solved by (OHAM). The contents of this chapter are published in Energy, 278 (2023) https://doi.org/10.1016/j.energy.2023.127805.