Introduction to Engineering Thermodynamics (FST 204) Lecture Note
Definition • Thermodynamics is derived from two words: ‘Thermo’ which means ‘Heat energy’ and ‘Dynamics’ which means ‘conversion’ or ‘transformation’ • Concisely, thermodynamics is a division of science that deals with conversion of energy from one form to another • The main forms of energy of interest in engineering thermodynamics are heat and work
Definition contd. • Work is the form of energy useful in displacement of a body • Heat is the form of energy transferred due to temperature gradient between two bodies
Applications of Engineering Thermodynamics • Engineering application of thermodynamic principles is the design of various systems using fluid properties to cause energy transformation • Applications in design of heat engines, refrigeration machines, air conditioning systems
Scope of Thermodynamics • It is limited to macroscopic properties of matter i.e. properties of large number of particles of systems • It considers the initial and final states of a system and not the mechanism of the process
Important fluid properties in thermodynamics • Density • Specific heat capacity • Temperature • Internal energy • Entropy • Enthalpy • Pressure • Specific volume • Mass
Fundamental concepts • System • Boundary • Surrounding • Open, Closed and Isolated • Homogenous and heterogeneous • Energy • Kinetic energy • Potential energy • Internal energy
Heat Engines • Heat engines are devices designed for the purpose of converting other forms of energy (usually in the form of heat) to work. Heat engines differ considerably from one another, but all can be characterized by the following: 1. They receive heat from a high-temperature source (solar energy, oil furnace, nuclear reactor, etc.). 2. They convert part of this heat to work (usually in the form of a rotating shaft). 3. They reject the remaining waste heat to a low-temperature sink (the atmosphere, rivers, etc.). 4. They operate on a cycle.