An engine or motor is a machine designed to convert a form of energy into mechanical energy. Heat engines burn a fuel to create heat, which is then used to create a force. Electric motors turn mechanical energy into mechanical motion. The pneumatic motors use the compressed air and the watch motors in the winding toys use elastic energy. In biological systems, molecular motors, such as myosins in the muscles, use chemical energy to create forces and eventually move.
In the case of sound levels, the operation of the motor is of greater impact with respect to mobile sources such as automobiles and trucks. Motor noise is a particularly important component of the noise of the mobile source for vehicles that run at lower speeds, where aerodynamics and tires are less significant. In general terms, gasoline and diesel engines emit less noise than equivalent turboshafts. Electric motors often emit less noise than their fossil fuel-based equivalents.
Pull-out motors, such as turbo-burses, turbo-reactors, and rockets, emit the greatest amount of noise because their method of producing thrust is directly related to sound production. Various methods have been designed to reduce noise. Gasoline and diesel engines are equipped with silencers; Newer turbochargers often have large fans to reduce the noise ratio, hot escape from turboshaft integrated into current leakage, and hush-kits exist for the oldest Bypass low turbofans.
There are no known methods to reduce the noise production of the rockets without a corresponding reduction in the thrust. Particularly notable kinds of engines include: Aircraft engine
Automobile engine, Model engine, Motorcycle engine, Marine propulsion engines such as Outboard motor,
Non road engine is the term used to define engines that are not used by vehicles on roadways including Railway locomotive engine, Spacecraft propulsion engines such as Rocket engine and Traction engine