Mechanical engineering is the branch of engineering that deals with the design, construction, and operation of machines and tools. It is one of the oldest and broadest branches of engineering.
The field of mechanical engineering can be divided into three main branches: thermal sciences, mechanics, and materials science. Thermal sciences deals with the study of heat transfer and thermodynamics; mechanics deals with the study of motion; and materials science deals with the study of materials.
Thermal Sciences
Thermal sciences deal with the study of heat transfer and thermodynamics. The most common type of heat transfer is conduction, which is the transfer of heat from one object to another through direct contact. Convection is another type of heat transfer that occurs when a fluid (liquid or gas) moves past a solid object, transferring heat from the hot fluid to the colder solid. Radiation is a third type of heat transfer that involves electromagnetic waves transferring heat from one place to another without any physical contact between them.
Thermodynamics is the branch of physics that studies how energy is converted into work and vice versa. The first law of thermodynamics states that energy can neither be created nor destroyed; it can only be converted from one form to another. The second law states that when energy is converted into work, some amountof entropy (disorder) must always be generated as well. The third law states that as temperature approaches absolute zero (- 273°C), all matter will reach a state known as “zero point” where there is no longer any thermal motion or entropy present in it.