This thesis aimed at studying the reacting system of boundary layer flow of CuO-Oil- based Nanofluid with heat generation through a vertical permeable surface.
A boundary layer is formed whenever there is a relative motion between the boundary and the fluid. The details of flow within the boundary layer are very important for the understanding of many problems in aerodynamics, including the wind stall, the skin- drag on an object, heat transfers that occur in high speed flight and in naval architecture for the designs of ships and submarines. The concept of boundary layer was first introduced by Prandtl in 1904 and since then it has been applied to several fluid flowproblems.
The science of fluid dynamics encompasses the movement of gases and liquids, interaction of fluid with solid and the study of forces related to these phenomena. It plays an important role in every aspect of our daily life for example from morning bath to evening coffee. It has potential applications in the field of science, engineering, manufacturing, transportation, environment, medicine, energy and others. Flows are important for the existence of natural and technical world. Properties of the fluid, forces acting on the fluid particles and boundaries of the flow domain determine the resultant flow pattern. Deformation of fluids occurs continuously under application of shear stress which makes them isotropic substances. Navier-Stokes equations are the fundamental equations of the fluid that portray the stream as either Newtonian or non-Newtonian Harlow and Amsden.
There is a broad scope of heat transfer applications in numerous industrial processes involving mechanical, electrical and chemical industry. Achieving higher convective rate of heat transfer in thermal systems and processes has always been the challenges facing Scientists and Engineers. As a result, this process requires an immensity amount of vitality to manage the method of fluid heating/cooling and transport of heat. It is known that cooling is necessary for maintaining the preferred performance and steadfastness of an engine.
Heat transfer fluids like water, oil, ethyl glycol and salt water collect and transport heat from the region with high temperature to the region with low temperature. In Automobiles, piston converts the heat generated as a result of the combustion of the fuel into mechanical work and drives the crankshaft in the course of the connecting rod. Continuous heating of the piston without proficient cooling can lead to elevated fuel and oil utilization, harmful exhaust emissions, reduction in engine power output or undeviating engine damage.
Heat transfer fluids are expected to have high thermal conductivity, high volumetric heat capacity, and low viscosity. On the other hand, the heat carrier fluids have low thermal conductivity and affect the proper functioning of the system. In order to guarantee durability, reliability and extend lifespan of an engine, there is need for use of heat carriers’ fluid with improved heat transfer properties. The innovative conception of nanofluid was proposed as a solution to these challenges.
Nanofluid, an improved heat transfer fluid, is a fluid-dispersed which contains nanoparticles of size range (1-100nm). The fluids such as oil, water and ethyl glycol are some of the fluids used in nanofluid. Materials commonly used as nanoparticles are chemically stable metals (copper, gold), metal oxides (CuO, Al O ) and Carbon in various forms (diamond, graphite, carbon nanotubes). The mixture of concentration of nanopaticles into the heat carrier fluids enhances the viscosity of nanofluids and other thermo-physical properties like thermal conductivity, specific heat capacity and density.
Oil based nanofluids is used in the cooling of electronic equipment, nuclear reactors, power transformers and automobile engines. Oil in an engine cushions the bearings in opposition to the shocks of firing cylinders. It serves as lubricant to neutralize the corrosive elements during combustions and prevents the metal surfaces of an engine from rust. It also serves as coolant agent for parts of engine that are not exposed to the water-cooling system.
Metal oxides are commonly used as thermal additives in Nanofluid due to their outstanding properties such as high thermal conductivity and excellent compatibility with base fluid. Al O , TiO , ZnO and CuO are the most popular metal oxides nanoparticles. Nanofluids containing metal oxides have exhibited special potentials in heat transfer applications. Among various metal oxides nanoparticles, CuO has higher thermal conductivity; it is a monoclinic crystal structure and has many attractive properties. CuO particles have spheroid shapes and most of the particles are under aggregate states. And to have an efficient Nanofluid, the particles should have spherical shape to have a higher critical dilute limit.
Excessive concentration of nanoparticles in base fluid at low temperature leads to increase in the density of nanofluid, which is the compactness of nanoparticles, it results into very thick nanofluid and this leads to viscous nano-oil which provides stronger fluid film and the thicker the nanofluid film, the more resistant it will be rubbed from lubricated surfaces. Nanofluids’ viscosity is the measure of its thickness or struggle to flow. It is directly connected with how well oil based nanofluid lubricates and protects surfaces that it moves through. However, very thick nanofluid offers excessive resistance to flow at low temperatures and as a result may not flow quickly enough to those parts requiring lubrication. It is therefore crucial that for nanofluid to be effective, it must exhibit moderate concentration of nanoparticles and the right thermo-physical properties at both the highest and the lowest temperatures which are necessity for proper functional of the engine.
Table of Contents
1. INTRODUCTION
1.1 Background of the Study
1.2 Statement of the Problem
1.3 Justification/ Motivation
1.4 Aim and Objectives
1.4.1 Aim
1.4.2 Objectives
1.5 Scope of the study
2. LITERATURE REVIEW
2.1 Definition of terms
2.1.1 Heat
2.1.2 Heat Transfer
2.2 Metal and Their Properties
2.3 Lubrication
2.4 Porous Channel
2.5 Nanofluids
2.6 Differential Equation
2.7 Initial and boundary value problems
2.8 Steady and unsteady flow
2.9 Governing Equation of Fluid
2.10 Review of Some Works on Porous Media
2.11 Review of Some Works on Chemically Reacting Systems
2.12 Review of Some Works on Nanofluids
2.13 Review of Thermophoresis and Brownian motion
2.14 Review of Some Works on the Density
2.15 Review of Some Works on the Specific heat capacity
3. METHODOLOGY/MATHEMATICAL FORMULATION
3.1 Research Methodology
3.2 Governing Equation
3.3 Case 1: Temperature dependent thermo physical properties
3.4 Case 2: Concentration of particles dependent thermo physical properties
3.5 Numerical procedure
3.6 Shooting method of boundary value problem
3.7 The Runge-Kutta
4. RESULTS ANS DISCUSSION
4.1 Numerical Results
4.1.1 Results for temperature dependent Thermo-physical properties (case 1) on Nusselt number, Sherwood and skin friction
4.1.2 Discussion of Results of case 1
4.1.3 The Results of Concentration of Nanoparticles dependent thermo-physical properties (case 2) on Skin Friction, Nusselt Number and Sherwood Numberat the Plate
4.2 Discussions of Results
5. CONCLUSION, RECOMMENDATIONS AND CONTRIBUTIONS TO KNOWLEDGE
5.1 Conclusion
5.2 Recommendations
5.3 Contributions to Knowledge
Research Objectives and Topics
This thesis aims to study the reacting system of boundary layer flow of CuO-oil-based nanofluid with heat generation through a vertical permeable surface, focusing on the influence of thermo-physical properties under temperature-dependent and concentration-dependent conditions.
- Mathematical modeling of steady, two-dimensional nanofluid flow.
- Transformation of partial differential equations into nonlinear ordinary differential equations.
- Numerical analysis using the fourth-order Runge-Kutta method and shooting technique.
- Investigation of thermo-physical properties (viscosity, density, specific heat, thermal conductivity).
- Evaluation of skin friction, Nusselt number, and Sherwood number.
Excerpt from the Book
1.1 Background of the Study
A boundary layer is formed whenever there is a relative motion between the boundary and the fluid. The details of flow within the boundary layer are very important for the understanding of many problems in aerodynamics, including the wind stall, the skin- drag on an object, heat transfers that occur in high speed flight and in naval architecture for the designs of ships and submarines. The concept of boundary layer was first introduced by Prandtl in 1904 and since then it has been applied to several fluid flowproblems. (Ajala et al. 2019)
The science of fluid dynamics encompasses the movement of gases and liquids, interaction of fluid with solid and the study of forces related to these phenomena. It plays an important role in every aspect of our daily life for example from morning bath to evening coffee. It has potential applications in the field of science, engineering, manufacturing, transportation, environment, medicine, energy and others. Flows are important for the existence of natural and technical world. Properties of the fluid, forces acting on the fluid particles and boundaries of the flow domain determine the resultant flow pattern. Deformation of fluids occurs continuously under application of shear stress which makes them isotropic substances. Navier-Stokes equations are the fundamental equations of the fluid that portray the stream as either Newtonian or non-Newtonian Harlow and Amsden, (1971.)
There is a broad scope of heat transfer applications in numerous industrial processes involving mechanical, electrical and chemical industry. Achieving higher convective rate of heat transfer in thermal systems and processes has always been the challenges facing Scientists and Engineers. As a result, this process requires an immensity amount of vitality to manage the method of fluid heating/cooling and transport of heat. It is known that cooling is necessary for maintaining the preferred performance and steadfastness of an engine.
Summary of Chapters
CHAPTER ONE INTRODUCTION: Provides the background and objectives of investigating CuO-oil-based nanofluid flow over a vertical permeable surface.
CHAPTER TWO LITERATURE REVIEW: Examines fundamental concepts in fluid dynamics, heat transfer, and prior research studies related to nanofluids and boundary layer flows.
CHAPTER THREE METHODOLOGY/MATHEMATICAL FORMULATION: Details the mathematical modeling process, including governing equations and the numerical procedure used for solving the system.
CHAPTER FOUR RESULTS ANS DISCUSSION: Presents numerical findings and graphs regarding velocity, temperature, and concentration profiles under various physical parameters.
CHAPTER FIVE CONCLUSION, RECOMMENDATIONS AND CONTRIBUTIONS TO KNOWLEDGE: Summarizes the key findings of the study and provides recommendations for practical industrial applications.
Key Words
Nanofluid, CuO-Oil, Boundary layer flow, Heat transfer, Heat generation, Numerical method, Runge-Kutta, Viscosity, Thermal conductivity, Specific heat, Skin friction, Nusselt number, Sherwood number, Permeable surface, Concentration
Frequently Asked Questions
What is the primary goal of this research?
The thesis aims to investigate the behavior of CuO-oil-based nanofluid boundary layer flow over a vertical permeable surface under the influence of heat generation.
What are the main thematic areas covered in this work?
The study covers thermodynamics, fluid mechanics, nanotechnology applications in cooling systems, and numerical analysis of nonlinear differential equations.
Which mathematical method is utilized in the study?
The study uses mathematical modeling to derive partial differential equations, which are reduced to nonlinear ordinary differential equations and solved using the fourth-order Runge-Kutta method alongside a shooting technique within the MAPLE 18 software package.
What specific nanofluid combinations were simulated?
The study considers copper oxide (CuO) nanoparticles dispersed within an engine oil base fluid.
What is the significance of the thermo-physical properties mentioned?
Parameters like thermal conductivity, specific heat, and density directly impact heat transfer efficiency and flow behavior, which are critical for engine cooling and performance.
What are the key findings regarding skin friction?
The results show that skin friction is significantly influenced by physical parameters such as density, suction, and heat generation, with specific trends identified for both temperature-dependent and concentration-dependent property cases.
How is the "case 1" condition defined?
In Case 1, the fluid properties (viscosity, thermal conductivity, density, and specific heat) are assumed to be dependent on the fluid temperature.
How is the "case 2" condition defined?
In Case 2, these same thermo-physical properties are assumed to depend on the concentration of the dispersed nanoparticles.
- Arbeit zitieren
- Ph.D Lateefat Aselebe (Autor:in), 2022, Reacting System of Boundary Layer Flow of CuO-Oil-Based Nanofluid with Heat Generation through a Vertical Permeable Surface, München, GRIN Verlag, https://www.grin.com/document/1333582
