Heat and mass transfer phenomena are found everywhere in nature. They are of importance in almost all branches of Science and Technology for their varied practical involvement. Some of the fields wherein heat and mass transfer flows are significant are Power Engineering, Civil Engineering, Chemical Engineering, Aeronautics, Refrigeration and Air conditioning, Environmental Engineering, Biological, Metallurgical and Industrial processes. The aim of the present dissertation is to study the radiation effects on unsteady heat and mass transfer flow of a chemically reacting fluid. Chapter – I deals with the radiation effects on unsteady heat and mass transfer flow of a chemically reacting fluid past a semi-infinite vertical plate with viscous dissipation. Chapter – II deals with the radiation effects on unsteady heat and mass transfer flow of a chemically reacting fluid past an impulsively started vertical plate.
Covers a wide range of practical fluid mechanics, heat transfer, and mass transfer problems This book covers the many issues that occur in practical fluid mechanics, heat transfer, and mass transfer, and examines the basic laws (the conservation of matter, conservation of momentum, conservation of energy, and the second law of thermodynamics) of these areas. It offers problem solutions that start with simplifying engineering assumptions and then identifies the governing equations and dependent and independent variables. When solutions to basic equations are not possible, the book utilizes historical experimental studies. It also looks at determining appropriate thermo-physical properties of the fluid under investigation, and covers solutions to governing equations with experimental studies. Case Studies in Fluid Mechanics with Sensitivities to Governing Variables offers chapters on: draining fluid from a tank; vertical rise of a weather balloon; wind drag forces on people; Venturi meter; fluid’s surface shape in a rotating cylindrical tank; range of an aircraft; designing a water clock; water turbine under a dam; centrifugal separation of particles; ideal gas flow in nozzles and diffusers; water supply from a lake to a factory; convection mass transfer through air-water interface; heating a room by natural convection; condensation on the surface of a vertical plate in laminar flow regime; bubble rise in a glass of beer; and more. Covers a broad spectrum of problems in practical fluid mechanics, heat transfer, and mass transfer Examines the basic laws of fluid mechanics, heat transfer and mass transfer Presents solutions to governing equations with experimental studies Case Studies in Fluid Mechanics with Sensitivities to Governing Variables will appeal to engineers working in thermo-physical sciences and graduate students in mechanical engineering.
This book presents a new technique to enhance heat transfer coefficient of double pipe heat exchanger. Heat transfer enhancement is the practice of modifying a heat transfer surface to increase the heat transfer coefficient between the surface and fluid. An experimental investigation has been conducted to evaluate the heat transfer performance of double pipe heat exchanger. Experiments were carried out under two condition of full-length and half-length twisted tape inserts in double pipe heat exchanger and result are compared with the smooth double pipe heat exchanger. By inserting twisted tape inside the tube, they act as turbulence promoter. It mixes the boundary fluid with bulk fluid and boundary layer thickness is reduced by imparting a rotational motion to a fluid flowing inside the tube of double pipe heat exchanger.The effect of the full-length and half-length twisted tape on the heat transfer coefficient and pressure drop is experimentally investigated in case of different mass flow rate. The performance evaluation of the smooth tube, and tube with full length and half-length tapes were carried out on the basis of equal mass flow rates and unit pressure drop.
In chapter I,we have discussed the fundamental concept of heat and mass transfer. In this chapter we have shown some relation among the various parameters related to heat and mass transfer of fluid. In chapter II, we have discussed about forced convection. The temperature distributions in a forced parallel flow near the wall with constant temperature and constant heat flux have been discussed here.In chapter III, an attempt has been made to discuss the natural convection. The basic equations related to various free convective processes have been shown with the help of some nondimentional numbers. In chapter IV, the combine effects of forced and free convection in fluid have been taken into account. Here we have shown the convective boundary layer related to mixed convection. In chapter V, we have investigated the mass transfer of fluid. Here, we have discussed about mass transfer, forced and fluxes, diffusion equation. In chapter VI, we have discussed about some additional convective process. Various processes like melting, atmospheric convection, oceanic convection etc. have been taken here. In describing special types of convective flow we have considered porous medium.
This book provides a comprehensive analysis of heat and mass transfer effects on magnetohydrodynamic convective flows. Basic idea are stressed and discussed in detailed full developments of results are provided. It helps researchers, students and engineers and scientists who work in the area of heat transfer heat transfer on magnetohydrodynamic convective flows. Applications of the problem are also discussed.
Viscosity and thermal conductivity are two temperature dependent properties of matter. In most of the problems of fluid mechanics, the viscosity and thermal conductivity of the fluid were assumed to constant. However it is known that these physical properties can change significantly with temperature.When the effect of variable viscosity and thermal conductivity are taken in to account, the flow characteristics are substantially changed from that of constant cases. Most fluids however have temperature dependent properties, and under circumstances where large temperature gradients exist across the fluid medium, fluid properties often vary significantly. Under many conditions, ignoring such variations may cause serious in-accuracy in estimating heat transfer rates. So, here in this book we are considering some heat and mass transfer problems of fluid mechanics where the effects of variable viscosity and thermal conductivity are observed under different flow conditions. The book will be helpful for researchers working in the field of heat and mass transfer flow.
FLOW PROBLEMS WITH HEAT AND MASS TRANSFER. In this Dissertation, investigations are carried out on Natural convection flow of fluid between two infinite vertical parallel plates for different physical situations as well as different fluid properties. The different thermal conditions considered in this dissertation include symmetric and asymmetric heating of the boundaries, periodic temperature variation on the boundaries, viscous dissipation heating as well as the role of Non- Fourier energy equation on convective heat transfer. The dissertation also investigated the influence of heat generation or absorption and mass leakage (suction/injection) through the channel boundaries. Closed form solutions are obtained for momentum, energy and concentration equations for different physical situations. It is hoped that the result presented in this dissertation will be of use in validating Computer routines for numerical solutions of more complex natural convection fluid flows in the presence of heat and mass transfer and in stimulating needed experimental work in this area.
1stchapter, a two dimensional MHD natural convection and mass transfer flow past an inclined semi infinite vertical plate in the presence of heat generation and porous medium was discussed 2ndchapter, a free convective flow of viscous incompressible fluid of small electrical conductivity through a porous medium bounded by an oscillating infinite porous plate in slip flow regime. 3rdchapter, an analysis carried out to study the nonlinear MHD flow with heat and mass transfer characteristics of an incompressible, viscous, electrically conducting Boussinesq fluid over a vertical oscillating porous permeable plate embedded in a porous medium. 4thchapter, a theoretical analysis of influence of radiation effect on a two dimensional MHD convection and mass transfer flow of an electrically conducting fluid past an inclined semi-infinite vertical porous plate embedded in a porous medium. 5thchapter, a theoretical analysis of free convective two dimensional unsteady flow of a visco-elastic incompressible fluid through a porous medium bounded by an infinite vertical porous plate subjected to a uniform suction was presented under the influence of a uniform transverse magnetic field.
Heat transfer fluids play very important roles in many industries including power stations, production processes, transportation and electronics. The so-called nanofluid becomes a hot debate among the researchers and it is leading to a new revolution in thermal and heat transfer performance as new working fluid in recent decade. The present work studied the typical water based Cu nanofluid and CNTs nanofluids thermal performance: The convective heat transfer coefficient of Cu nanofluid with different volume concentrations under different flow regimes has been investigated and given very positive suggestions for Cu nanofluid application as heat transfer working fluid; For CNTs nano fluid, the research focus on the enhancement of thermal conductivity by influence of CNTs dispersion. The methods and guidelines probably bring audience bright ideas about how to better use the merits of CNTs as high efficient heat transfer nanofluid.
Research during the past decade has shown that dispersions of nanoscale particles in conventional heat transfer fluids, called nanofluids, can enhance its thermal conductivity. The convective heat transfer coefficient of this engineered fluid is substantially higher than that of the base fluid. The nanofluid''s superior heat transfer capability depends on its thermophysical properties. The authors of this treatise, from their experimental expertise, have presented useful correlations for the thermophysical properties, which are valuable for engineering applications using nanofluids. Performing three-dimensional numerical investigations, the authors have shown that the use of nanofluids in a radiator can reduce the size of the heat exchanger surface area and the required pumping power in comparison with the base fluid on the basis of equal heat transfer.
The experimental apparatus is located at MNIT, Jaipur. To perform experiments in forced convective heat transfer at mass fluxes from 400 to 1000 kg/m2-s, heat fluxes from 0.1 to 0.5 MW/m2 and percent Al2O3 volume fraction varying from 0.25 to 1% At constant pressure 1 bar and environmental temperature for investigating the convective heat transfer characteristics of Al2O3/water nanofluid and to extend the available database and report information on heat transfer characteristics of Al2O3/water nanofluid in an annular test section with an inner heating surface. Forced flow conditions and particle migration is suggested to be an important mechanism. The results of the present investigation are summarized as follows: i. This study revealed that heat transfer increases with increase in mass flux at all given ranges of percent Al2O3/water nanofluid and heat fluxes. ii. The results of this experimental work shows that heat transfer increases with heat flux applied. iii. Heat transfer increases with addition of the Al2O3 nanoparticles in the base fluid.
This broad-based book covers the three major areas of Chemical Engineering. Most of the books in the market involve one of the individual areas, namely, Fluid Mechanics, Heat Transfer or Mass Transfer, rather than all the three. This book presents this material in a single source. This avoids the user having to refer to a number of books to obtain information. Most published books covering all the three areas in a single source emphasize theory rather than practical issues. This book is written with emphasis on practice with brief theoretical concepts in the form of questions and answers, not adopting stereo-typed question-answer approach practiced in certain books in the market, bridging the two areas of theory and practice with respect to the core areas of chemical engineering. Most parts of the book are easily understandable by those who are not experts in the field. Fluid Mechanics chapters include basics on non-Newtonian systems which, for instance find importance in polymer and food processing, flow through piping, flow measurement, pumps, mixing technology and fluidization and two phase flow. For example it covers types of pumps and valves, membranes and areas of their use, different equipment commonly used in chemical industry and their merits and drawbacks. Heat Transfer chapters cover the basics involved in conduction, convection and radiation, with emphasis on insulation, heat exchangers, evaporators, condensers, reboilers and fired heaters. Design methods, performance, operational issues and maintenance problems are highlighted. Topics such as heat pipes, heat pumps, heat tracing, steam traps, refrigeration, cooling of electronic devices, NOx control find place in the book. Mass transfer chapters cover basics such as diffusion, theories, analogies, mass transfer coefficients and mass transfer with chemical reaction, equipment such as tray and packed columns, column internals including structural packings, design, operational and installation issues, drums and separators are discussed in good detail. Absorption, distillation, extraction and leaching with applications and design methods, including emerging practices involving Divided Wall and Petluk column arrangements, multicomponent separations, supercritical solvent extraction find place in the book.
Prob.(I): Thermo diffusion and chemical effects on heat transfer in MHD mixed convection flow and mass transfer past an infinite vertical plate with Ohmic heating and viscous dissipation have been studied. Thermal diffusion caused both the fluid velocity and temperature to fall due to the presence of the chemical effect. Velocity and temperature profiles are higher for mercury than electrolytic solution. Soret effect increased the concentration of the fluid while chemical effect decreased. Prob.(II): A three - dimensional MHD flow with heat and mass transfer through a semi-infinite porous medium, in the presence of viscous dissipative heat and chemical reaction, is considered. A uniform magnetic field is applied normal to the bounding surface. Velocity of the fluid is increasing with velocity ratio parameter, Hartman number and Reynolds number whereas decreases with permeability parameter. Increase in Prandtl number and Reynolds number led to increase in temperature of the fluid. Fluid concentration decreased with increase in Chemical parameter and Schmidt number.
Transport processes represent important life-sustaining elements in all humans. These include mass transfer processes, including gas exchange in the lungs, transport across capillaries and alveoli, transport across the kidneys, and transport across cell membranes. These mass transfer processes affect how oxygen and carbon dioxide are exchanged in your bloodstream, how metabolic waste products are removed from your blood, how nutrients are transported to tissues, and how all cells function throughout the body. A discussion of kidney dialysis and gas exchange mechanisms is included. Another element in biomedical transport processes is that of momentum transport and fluid flow. This describes how blood is propelled from the heart and throughout the cardiovascular system, how blood elements affect the body, including gas exchange, infection control, clotting of blood, and blood flow resistance, which affects cardiac work. A discussion of the measurement of the blood resistance to flow (viscosity), blood flow, and pressure is also included. A third element in transport processes in the human body is that of heat transfer, including heat transfer inside the body towards the periphery as well as heat transfer from the body to the environment. A discussion of temperature measurements and body protection in extreme heat conditions is also included. Table of Contents: Biomedical Mass Transport / Biofluid Mechanics and Momentum Transport / Biomedical Heat Transport
An understanding of the heat and mass transfer phenomena in porous media implies a good description of the flow behaviour within it; this fact is of fundamental importance to many chemical engineering systems such as packed bed extration or catalytic reaction equipment. In general, porous media is described as an effectively homogeneous system, neglecting the complexities of the flow within the void space studies equipment. The details of this local flow process may, however, be the most important factor influencing the behaviour of a given physical process ocurring within the system. Computational Fluid Dynamics as a simulation tool allows obtaining a more approached view of the fuid flow and transport mechanisms in supercritical packed bed equipment, though the resolution of continuity, momentum, mass and energy balances around the complex geometry of the studies cases. In this book, CFD is used for solving fluid flow and heat and mass transfer phenomena in packed beds with supercritical solvents, developing a modeling strategy applicable to the design of heterogeneous reaction and extration equipment.