Preface to the Second Edition

It is my great pleasure to present the second edition of the Basic Mechanical Engineering textbook after the much praised first edition of the book. Due to continuous change in the curriculum of the engineering education, it becomes necessary to modify the contents of the book as per the requirements of the universities. After the first edition, it has been observed that few topics of the book are not much relevant for the first year engineering students, for example, Chapter 13—Lifting Machines and Chapter 23—Unconventional Machining Processes and therefore, these two chapters are removed from the second edition of the book.

Also, in the second edition, several topics have been added. Global warming and biofuels are now discussed in detail in Chapter 2. Due to fast change in the technology, some advanced technologies such as Multi-point Fuel Injection Engine (MPFI), Common Rail Direct Injection (CRDI), Hybrid Engines have been introduced in Chapter 6. Chapter 13 has been upgraded by removing the Lifting Machines and adding spring, CAM and followers, and bushing and bearing. In Chapter 19, grinding and surface finishing processes have been included. Smithy works have been added in Chapter 21. Introduction to Automation and Robotics have been included in Chapter 22.

In addition to the above changes, some minor improvements have been done in the entire book and the questions asked in various university examinations have also been included. These questions are indicated by an asterisk (*) symbol.

Chapter Structure and Coverage

This book provides a basic knowledge of the various aspects of mechanical engineering. The chapter structure and coverage are discussed below:

Chapter 1 covers the laws of thermodynamics and properties of gases. Under the laws of thermodynamics, we first discuss, second and third laws of thermodynamics, concepts of specific heat, enthalpy, entropy, etc., followed by the discussion on properties of gases such as Boyle’s Law, Charles’s Law, Gay Lusssac’s Law, combined gas law and gas constant, etc.

Chapter 2 deals with fuels and their combustion. The various types of fuels such as solid, liquid, and gaseous fuels are introduced and their applications for power generation have been discussed. Again to measure the calorific value of fuel, a basic idea about calorimeters and their working procedure has been given.

Chapter 3 describes power plant engineering. In this chapter, the methods of conversion of various forms of energy into mechanical energy and electrical energy along with an introduction to the basic concepts of thermal power plant, hydroelectric power plant, and nuclear power plant with some of the non-conventional energy sources has been discussed.

Chapter 4 covers steam properties and its generation. Various properties of steam such as internal energy, enthalpy, and entropy at different ambient conditions are discussed. The steam table and the Mollier diagram that are helpful in showing the methods to find the properties of steam at the given condition are also introduced. In addition to this, the working of steam generators (boilers) and the functions of various mountings and accessories used in boilers are also discussed.

Chapter 5 deals with the conversion of heat energy into mechanical energy or shaft power followed by discussion on the working of steam engines, steam turbines, and gas turbines in detail. These are the devices used to convert heat energy carried by steam or gases into shaft power. The shaft power is further converted into electrical energy using an electricity generator.

Chapter 6 describes internal combustion engines and their working. There is a wide scope to discuss various mechanisms and developments in I.C. engines, we have however focused our discussion only to the basic concepts of working on I.C. engines such as petrol (Gasoline) engines, diesel engines, two-stroke engines, four-stroke engines, thermodynamic cycles, and performance measurement of an I.C. engine.

Chapter 7 deals with the various modes of heat transfer. It gives a basic idea about the thermal conductivity and the overall heat transfer coefficient.

Chapter 8 covers refrigeration and air conditioning. Refrigeration deals with the various types of processes such as vapor compression refrigeration, air refrigeration, absorption type refrigeration, and the properties of some of the refrigerants. Air conditioning deals with psychrometric properties of air and the processes to control these properties.

Chapter 9 covers fluid mechanics and hydraulic machines. Fluid mechanics provides an introduction to fluid statics and fluid dynamics. Hydraulic machines deal with the working of water turbines, water pumps, hydraulic coupling, and torque converters.

Chapter 10 describes air compression systems. Single-stage and multistage compressors, as well as rotary compressors, are discussed in detail and vane type compressors, centrifugal compressors, and axial flow compressors are discussed at an introductory level.

Chapter 11 describes centroid, the center of gravity and moment of inertia for various sections. Parallel and perpendicular axis theorems are used to find the moment of inertia for the different cross sections. This chapter is very useful to analyze the dynamics of a machine element.

Chapter 12 describes stress and strain, that is, the properties of materials under various types of loading. It also demonstrates relationships among different types of elastic constants.

Chapter 13 deals with springs, different types of CAMs and followers, bushing and bearing.

Chapter 14 describes the working of flywheel and governor. Flywheel works just like an energy reservoir while governor controls the speed by controlling the fuel supply.

Chapter 15 deals with power transmission devices such as belt drive, chain drive, and gear drive. In belt drive, we discuss open and cross belt drives and their applications; in the chain drive, we provide a basic idea about the power transmission mechanisms; and in gear drive, we discuss different types of gears and working on gear trains.

Chapter 16 covers other types of power transmission devices such as coupling and clutch. It also discusses the mechanisms of various types of braking systems. Clutch provides a flexibility to engage or disengage the engine from the load.

Chapter 17 covers some of the important engineering materials and their mechanical properties such as tensile strength, hardness, toughness, ductility, malleability, etc. Some practical methods to measure the tensile strength, hardness, and toughness are also discussed.

Chapter 18 demonstrates various types of measurements such as the measurement of pressure, velocity, flow, force, torque, etc. Also, some of the devices used in metrology have been introduced such as vernier caliper, screw gauge, sine bar, dial gauge and slip gauge.

Chapter 19 deals with the mechanism of machining and working of various machine tools such as lathe, shaper and planer, drilling and boring, and milling operations.

Chapter 20 describes the primary shaping (casting) and joining (welding) processes such as welding. In this chapter, sand casting and other casting processes with casting defects are discussed. Different conventional and non-conventional welding and allied processes with welding defects are also explained.

Chapter 21 covers various forging operations, sheet metal processes, and powder metallurgy. These are the basic processes frequently used in mechanical workshops.

Chapter 22 provides a basic idea of the numerical control machine, computer numerical control machine, and direct numerical control machines. Also, the basic concepts of automation and robotics have been discussed. These are the machines used in metal cutting with improved productivity and accuracy.

Chapter 23 deals with heat treatment processes. In this chapter, the mechanism of controlling the mechanical properties by heating and cooling with different rates is discussed.