Thermodynamics is derived from two Greek words
- Therme, which means heat,
- Dynamis, which means power.
Thermodynamics is a branch of science that deals with the relationships and conversions between heat and other forms of energy.
Thermodynamics deals with heat, work and temperature, and their relation to energy, radiation and physical properties of matter.
In simple terms, it is the study of how heat energy or thermal energy is converted into other forms of energy and how mechanical work is done.
Laws of Thermodynamics
Thermodynamics is governed by a set of principles and laws that describe the behavior of energy and matter, particularly in terms of temperature, pressure, and volume. The following are the laws that govern major concepts in thermodynamics.
- Zeroth law of thermodynamics
- First law of thermodynamics
- Second law of thermodynamics
- Third law of thermodynamics
Branches of thermodynamics
Thermodynamics is classified into the following four branches:
Classical Thermodynamics: macroscopic systems-pressure and Temperature.
Statistical Thermodynamics: microscopic behavior-atoms and molecules.
Chemical Thermodynamics: chemical reactions and processes-Gibbs free energy, enthalpy, and the equilibrium constant.
Equilibrium Thermodynamics: thermodynamic equilibrium-Temperature, pressure, and density are uniform and unchanging over time.
Non Equilibrium Thermodynamics: heat transfer, chemical reactions, and fluid flow-Temperature, pressure, and density are not uniform and changes over time.
Engineering Thermodynamics: engines, refrigerators, power plants, and HVAC systems-practical applications and efficiency.
Biological Thermodynamics: metabolism, protein folding, and cellular processes-living organisms.
Environmental Thermodynamics: Climate modeling, atmospheric thermodynamics, and energy balance in ecosystems-environmental systems and processes.
Microscopic vs Macroscopic approach:
Macroscopic approach: In macroscopic approach certain amount of matter is considered, without considering the events occurring at molecular level(atoms and molecules).It considers the effects which can be perceived by human senses.
It is also called classical thermodynamics.
Example : pressure is the average rate of momentum due to all molecular collisions made on a unit area. The effects of pressure can be felt. Temperature is also the other example.
Microscopic approach: It focuses on understanding the behavior of individual particles within a system. This includes their positions, velocities, energies, and interactions.
All the results of macroscopic approach is derived from microscopic and statistical study of matter.
Applications of Thermodynamics
The applications of thermodynamics laws and principles are found in all fields of energy technology, such as in steam and nuclear power plants, internal combustion engines, gas turbines air conditioning, gas dynamics ,jet propulsions, rocket sciences and in energy conversion devices.