Defining Entropy (S) through the Clausius Inequality
Consider two heat engines, one a reversible (Carnot) engine and the other an irreversible heat engine. For purposes of developing the Clausius Inequality we assume that both engines are sized…
Carnot’s Theorem
This theorem states that no engine working between two given temperatures can be more efficient than a reversible engine working between the same two temperatures and that all the reversible…
Reversible and Irreversible Process
The reversible process is the ideal process which never occurs, while the irreversible process is the natural process that is commonly found in nature. When we tear a page from…
What is Kelvin Planck Statement?
It states that “It is impossible to construct a device which operates on a cycle and produces no other effect than the transfer of heat from a single body in order…
What is the Second Law of Thermodynamics?
The laws of thermodynamics describe the relationships between thermal energy, or heat, and other forms of energy, and how energy affects matter. The First Law of Thermodynamics states that energy…
Heat Engine and Heat Pumps
One of the most important things we can do with heat is to use it to do work. Do you know how a heat engine or a pump works? Well,…
Mollier Diagram for Water-Steam
The diagram below can be used to determine enthalpy versus entropy of water and steam. The Mollier diagram is useful when analyzing the performance of adiabatic steady-flow processes, such as…
Phase Diagrams of Pure Substances:
In thermodynamics, a system is a region of space of which we have some interest. Often the system will consist of one or several pieces of equipment that we wish to use…
COMPRESSIBILITY FACTOR
Compressibility factor, usually defined as Z = pV/RT, is unity for an ideal gas. It should not be confused with the isothermal compressibility coefficient. In most engineering work, the compressibility…
What is the state principle for simple compressible systems?
Definition of the state principle For a simple compressible system, values for any two independent intensive properties determine the values of all other intensive properties. Definition of simple compressible systems Systems of commonly encountered…
