Heat is a concept that is important to understand in various engineering fields. It is particularly relevant for civil, mechanical and chemical engineers because heat transfer plays a key role in material selection, machinery efficiency and reaction kinetics, respectively.Heat transfer is a branch of thermal engineering concerns the generation, use, conversion, and exchange of thermal energy (heat) between physical system of different temperature.There are three different ways of heat transfer:In conduction, heat is transferred by particles vibrating through direct contact.convection, heat energy is carried by the movement of particles of matter. In radiation, heat is carried directly by electromagnetic waves.Both conduction and convection require matter/medium to transfer heat. If there is a temperature difference between two systems heat will always find a way to transfer from the higher to lower system.
The subject of heat transfer deals with both, i.e. how heat transfer rates can be increased and how can they be decreased.A great part of energy that we utilize is in the form of thermal energy thus the knowledge of Heat transfer therefore is crucial for designing systems that involve heat.