Thermal engineering
Thermal engineering is a specialized sub-discipline of mechanical engineering that deals with the movement of heat energy and transfer. The energy can be transferred between two mediums or transformed into other forms of energy.

Aspects of thermal engineering
Thermal engineering involves thermodynamics, liquid mechanics, and heat and mass transfer. This knowledge is important when operating almost any machine. Systems experience heat buildup from mechanical elements and electric circuits. This heat, if not redirected, can damage the system. Thermal engineers work to design the inclusion of fans or liquid circulators to regulate the internal temperature of the device. Computers and car batteries are two examples of this principle in action.

Thermal engineering focuses on the transfer of heat, fluid mechanics, and heating and cooling systems, such as those used in the electric power industry, the automobile industry and the heating, ventilation and air conditioning (HVAC) industry. Thermal engineers design systems that utilize various thermal sources of generated energy to create chemical, mechanical or electrical energy. They must have an understanding of thermodynamics, fluid mechanics and heat and mass transfer.

Heat transfer and mass transfer
Thermal engineers study heat transfer, which concerns the creation, utilization, conversion and exchange of heat between systems. Heat transfer is divided into several mechanisms, including:

Heat conduction: Also called diffusion, heat conduction is the direct exchange of kinetic energy of particles between two systems when one system is at a different temperature from another or its surroundings.
Heat convection: Heat convection involves the transfer of mass from one area to another. It occurs when the bulk of a fluid transfers heat as matter within the fluid moves.
Thermal radiation: Thermal radiation is heat transfer by electromagnetic radiation without the need for matter to be present between systems. Sunshine is a good example of radiation.

How does thermal engineering work?
Many processing plants use machines that utilize heat transfer. The thermal engineer is responsible for ensuring the right amount of energy is transferred for the machine's operation. Too much energy and the components could overheat and fail. Too little energy and the whole machine could shut down.