Study of Ag-water and Cu-water nanofluids

Abstract

Nanofluids attain significant attention in recent years due to its wide range of applications in industrial as well as socioeconomic domain such as automotive industry, medical arena, nuclear power plant cooling system as well as electronic cooling systems. Nanofluids are proved to be capable to handle some of the very important problems of emerged industrial growth most significant among which is the problem to enhance the heat transfer ability of fluids and thermal management. The idea of nanofluids was first given by Choi [1] in 2001. Nanofluids are now expected to play its role nearly in each and every industry. One of the main reasons for its wide spread implication is that its effective physical as well as thermophysical properties are adjustable according to need. Many authors have presented different kind of nanofluids for various flow geometries. Mention may be made to the interesting work of [2-11]. The geometry, deformation and intrinsic motion such as rotation and spin motion of individual fluid element may affect the motion of the fluid and its heat transfer characteristics. Classical Naiver Stokes model take into account the fluid motion as a whole but it does not discusses the behavior of individual fluid element when undergoes with spin inertia and micro-rotational inertia. The concept of micropolar fluid first proposed by Eringin [12] can explain these intrinsic behaviors at very best both theoretically and practically. Micropolar fluid model supports couple stress and body torque. Unlike the ordinary fluid models micropolar fluid model possesses the asymmetric stress tensor [13]. Micropolar fluid theory is developed to be a generalized case of Naiver Stokes model in fact the micro-rotation parameter that appear in the momentum equation shows the deviation of micropolar fluid model from that of classical Naiver Stokes model. Due to its tremendous applications and uses many researchers have examined various aspects of this useful theory. Some are quoted in the studies [14-22]. This dissertation is the motivation by aforementioned research. It consists of three chapters. Important definitions and relevant equations are presented in chapter one. It has been observed that some physical properties of nanofluids are sensible to temperature. In the heat transfer fluids the internal friction or heat generation or absorption phenomena can influence the fluid viscosity that is viscosity may change with temperature. Since the rise in temperature fasten the heat flow it is very necessary to study the effects of temperature dependent viscosity of the base-fluid on the heat transfer process. Chapter two therefor embraces the same theme. The subject matter of this chapter presents the meticulous review of the paper by Vajravelu Kuppalapalle [23]. In chapter three micropolar fluid theory is incorporated on nanofluids. The fluid viscosities (dynamic viscosity, spin gradient viscosity, micro-inertia density) are taken as inverse function of temperature. The flow is analyzed with different values of physical and thermophysical