12-04-2017, 04:29 PM
A fan is a machine used to create flow within a fluid, typically a gas such as air. The fan consists of a rotating arrangement of blades or blades acting on the fluid. The rotating assembly of blades and hub is known as impeller, rotor or runner. It is usually contained within some form of housing or case. This can direct airflow or increase safety by preventing objects from coming into contact with the fan blades. Most fans are powered by electric motors, but other power sources can be used, including hydraulic motors and internal combustion engines.
It can be understood in the following video: