Heat and Mass Transfer: Fundamentals and Applications 6th Edition Yunus. THE SOLUTIONS MANUAL

SOLUTIONS MANUAL Heat and Mass Transfer: Fundamentals and Applications 6th Edition Yunus Cengel; Afshin Ghajar TABLE OF CONTENTS CHAPTER 1: Introduction and Basic Concepts CHAPTER 2: Heat Conduction Equation CHAPTER 3: Steady Heat Conduction CHAPTER 4: Transient Heat Conduction CHAPTER 5: Numerical Methods in Heat Conduction CHAPTER 6: Fundamentals of Convection CHAPTER 7: External Forced Convection CHAPTER 8: Internal Forced Convection CHAPTER 9: Natural Convection CHAPTER 10: Boiling and Condensation CHAPTER 11: Heat Exchangers CHAPTER 12: Fundamentals of Thermal Radiation CHAPTER 13: Radiation Heat Transfer CHAPTER 14: Mass Transfer 1-1 Chapter 1: Introduction and Basic Concepts PROPRIETARY AND CONFIDENTIAL This Manual is the proprietary property of McGraw -Hill Education and protected by copyright and other state and federal laws. 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No reproduction or distribution without the prior written consent of McGraw -Hill Education. 1-2 Thermodynamics and Heat Transfer 1-1C Thermodynamics deals with the amount of heat transfer as a system undergoes a process from one equilibrium state to another. Heat transfer, on the other hand, deals with the rate of heat transfer as well as the temperature distribution withi n the system at a specified time. 1-2C (a) The driving force for heat transfer is the temperature difference. (b) The driving force for electric current flow is the electric potential difference (voltage). (a) The driving force for fluid flow is the pressure difference. 1-3C The rating problems deal with the determination of the heat transfer rate for an existing system at a specified temperature difference. The sizing problems deal with the determination of the size of a system in order to transfer heat at a specified rate for a specified temperature difference . 1-4C The experimental approach (testing and taking measurements) has the advantage of dealing with the actual physical system, and getting a physical value within the limits of experimental error. However, this approach is expensive, time consuming, and often impractical. The analytical approach (analysis or calculations) has the advantage that it is fast and inexpensive, but the results obtained are subject to the accuracy of the assumptions and idealizations made in the analysis. 1-5C Modeling makes it possible to predict the course of an event before it actually occurs, or to study various aspects of an event mathematically without actually running expensive and time -consuming experiments. When preparing a mathematical model, all the variables that affect the phenomena are identified, reasonable assumptions and approximations are made, and the interdependence of these variables are studied. The relevant physical laws and principles are invoked, and the problem is formulated mathematically. Finally, the problem is solved using an appropriate approach, and the results are interpreted. 1-6C The right choice between a crude and complex model is usually the simplest model which yields adequate results. Preparing very accurate but complex models is not necessarily a better choice since such models are not much use to an analyst if they are very difficult and time consuming to solve. At the minimum, the model should reflect the essential features of the physical problem it represents. 1-7C Warmer. Because energy is added to the room air in the form of electrical work. 1-8C Warmer. If we take the room that contains the refrigerator as our system, we will see that electrical work is supplied to this room to run the refrigerator, which is eventually dissipated to the room as waste heat. 1-9C The claim is false. The heater of a house supplies the energy that the house is losing, which is proportional to the temperature difference between the indoors and the outdoors. A turned off heater consumes no energy. The heat lost from a house to the outdoors during the warming up period is less than the heat lost from a house that is already at the temperature that the thermostat is set because of the larger cumulative temperature difference in the latter case. For best practice, the heater should be turned off when no one is at home during day (at subfreezing temperatures, the heater should be kept on at a low temperature to avoid freezing of water in pipes). Also, the thermostat should be lowered during bedtime to minimize the temperature difference between the indoors and the outdoors at night and thus the amount of heat that the heater needs to supply to the house.