الفهرس 
General introductionOnly 14 pages are availabe for public view
 |  | from | 349 |  |  |
| | | from | 349 | | |
Abstract
The primary goal of this thesis is to investigate the flow of an electric conducting non-Newtonian nanofluid under the influence of an external Direct Current (DC) across different geometric conduits. When the DC is applied, it triggers the movement of mobile charged particles within the electric double layer (EDL), resulting in the generation of an electro-osmotic flow (EOF) which has significant impacts on the fluid’s flow behavior. It is worth noting that the flow isn’t steady (unsteady flow) when viewed from the laboratory frame (a fixed frame). However, the time factor can be isolated by transitioning the flow to a moving frame that aligns with the wave speed. Furthermore, the study investigated the impacts of several effects on the flow behavior such as the presence of external magnetic field, induced magnetic field, viscous dissipations, thermal radiation, and chemical reactions with activation energy. Additionally, the governing equations which represent velocity, temperature, and nanoparticle concentration have been solved analytically using the Homotopy Perturbation Method (HPM). Furthermore, in Chapters 4 and 6, these equations are solved numerically using the Runge-Kutta-Merson method, besides the analytical solution provided by the HPM. Upon comparing the results, it is observed that they are extremely close. The results of this thesis have various applications in the biological, chemical, and industrial fields such as printing technology, lubrications and braking systems, drug delivery, tumor therapy, DNA amplification, and purification of crude oil.
The thesis is organized into six chapters, outlined as follows:
Chapter 1
This chapter provides a comprehensive introduction, covering the most essential and fundamental concepts that will be addressed in the subsequent five chapters, including:
• Models of non-Newtonian fluids.
• The mechanism of the peristaltic flow.
• The electro-osmotic flow.
• Nanofluids and their characteristic equations.
• The equations that control the electromagnetic fields.
• Modified Darcy’s law for porous medium
• Chemical reaction in the presence of Activation energy
Chapter 2
In this chapter, we investigated the electro-osmotic peristaltic flow of an incompressible non-Newtonian nanofluid in an inclined uniform channel. Moreover, the fluid obeys the Papanastasiou model with the effect of couple stress and the flow is through a porous medium that follows Darcy’s law in a modified form. In addition, other effects were also considered such as mixed convection, chemical reaction, and viscous couple stress dissipation. Furthermore, the governing equations for the fluid’s velocity, temperature, and concentration of the nanoparticles are simplified under the assumptions of wave transformation, long wavelength, and low Reynolds number. These simplified equations were then solved analytically using the homotopy perturbation method. In addition, a series of figures are employed to visually represent and discuss the effects of the entering physical parameters.
It is worth noting that the content of this chapter is published in the scientific journal ”International Journal of Applied Electromagnetics and Mechanics ” (Scopus Q3 with impact factor 0.536).
Chapter 3
In this chapter, we focused on the electro-osmotic effect on the peristaltic transport of a non-Newtonian nanofluid inside a horizontal microchannel. The fluid obeys Williamson’s model, and flows through a porous medium that adheres to modified Darcy’s law. In addition, the effects of chemical reactions with the contribution of activation energy are taken in consideration. The system of equations that governs the velocity, temperature, and concentration of nanoparticles distributions were transitioned to the moving frame of reference and simplified under the assumptions of a long wavelength and low Reynolds number. The homotopy perturbation method was used to get a semi-analytical solution for the simplified governing equations. Moreover, a set of figures was used to illustrate and discuss the role of the physical parameters entering the problem on the obtained solutions.
It is worth noting that the content of this chapter is published in the scientific journal ”Indian Journal of Chemical Technology” (Scopus Q4 with impact factor 0.76).
Chapter 4
In this chapter, we studied the unsteady peristaltic flow of a non-Newtonian nanofluid in the presence of the electro-osmosis phenomenon. The Sutterby model is chosen to represent non-Newtonian behavior. Furthermore, the flow took place through a porous medium that follows a modified form of Darcy’s law. Additionally, the impacts of Dufour and Soret effects, chemical reaction, activation energy, viscous dissipation, heat generation, and thermal radiation were considered. A wave transformation was applied to isolate the time factor and hence the flow is considered to be steady. Subsequently, the governing equations describing the velocity and the temperature distributions of the fluid, and the nanoparticle concentrations are simplified under the assumptions of a long wavelength and low Reynolds number. The resulting simplified equations were solved analytically using the homtopy perturbation method. Furthermore, the system of equations is solved once more but numerically, by using the Runge-Kutta-Merson method. A comparison was made between the two solutions, which were found to be closely aligned. Moreover, set figures were employed to illustrate and discuss the impact of the physical parameters involved in the problem on the obtained solutions.
It is worth noting that the content of this chapter is published in the scientific journal ”Modern Physics Letters B” (Soups Q2 with impact factor 1.9).
Chapter 5
In this chapter, we focused on the peristaltic flow of a non-Newtonian nanofluid in a vertical uniform channel under the presence of external electric and magnetic fields, which led to the occurrence of both electroosmosis and induced magnetic field phenomena. The non-Newtonian fluid obeys the third-order model. Furthermore, the flow is through a porous medium which follows the modified form of Darcy’s law. Moreover, various external effects were also considered such as mixed convection, Dufour and Soret, chemical reaction, activation energy, viscous dissipation, and heat generation in the system. Additionally, the flow is transitioned to the moving frame (steady flow) by the means of wave transformation techniques. Subsequently, the governing equations are simplified under the consideration of long wavelength and low Reynolds number. The resulting simplified equations were then analytically solved using the homotopy perturbation method (HPM). Furthermore, a set of figures was utilized to visually illustrate and discuss the influence of the various physical parameters involved in the problem on the solutions obtained.
It is worth noting that the content of this chapter is published in the scientific journal ”Egyptian Journal of Chemistry” (Soups Q2 impact factor 1.57).
Chapter 6
In this chapter, we investigated the impact of electro-osmosis on the peristaltic flow of micropolar nanofluid fluid with heat and mass transfer. The fluid under investigation is a Newtonian fluid with a micropolar structure, and it flows through a micro-channel that exhibits peristalsis along its walls. Moreover, the system is subjected to various external effects, including a uniform magnetic field, the electroosmotic phenomenon, heat absorption, and a chemical reaction with activation energy. The problem is mathematically modulated by a system of non-linear partial differential equations that govern the velocity, temperature, and nanoparticle concentration. The governing equations were simplified under the consideration of long wavelength and low Reynolds number. Subsequently, the simplified equations are solved both analytically using the homotopy perturbation method, and numerically, using the Runge-Kutta-Merson method. A comparison was made between the solutions, which were found to be closely aligned. Furthermore, a series of figures were employed to provide visual representation and discussion of the implications of the physical properties.
It is worth noting that the content of this chapter is published in the scientific journal ”Modern Physics Letters B” (Soups Q2 with impact factor 1.9).