The Manson engine is a
hot air engine
A hot air engine (historically called an air engine or caloric engine) is any heat engine that uses the expansion and contraction of air under the influence of a temperature change to convert thermal energy into mechanical work. These engines m ...
that was first described by A. D. Manson in the March 1952 issue of ''Newnes Practical Mechanics''-Magazines.
[ Manson engines can be started in either direction (clockwise or anti-clockwise).][ It has a stepped piston. The front part acts as a displacer and the back part acts as a work piston (the displacer and the work piston move as a single component).][ The engine only requires three moving parts: piston,][ piston rod, and crank.
The engine is double acting,][ using both the expansion of the warmed air and atmospheric pressure overcoming the reducing pressure of the cooling air to do work.][
The engine currently has no commercial or practical applications. The engines are built mainly as desk toys, physics demonstrations, and novelties.][
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Functioning mechanism
* Phase 1 (cooling down the work medium, suction stroke)
** when the Piston is moved toward the heat source, the hot gas inside the engine is moved to the cool side of the cylinder.
** the gas is cooled there, resulting in pressure dropping below atmospheric, further moving the piston toward the heat source.
* Phase 2 (top dead centre)
** When the piston reaches top dead centre, the inlet valve is open, releasing the vacuum.
** the flywheel keeps the piston moving
* Phase 3 (heating up the work medium, expansion stroke)
** when the piston is moving away from the heat source, the air is pushed toward the heat source.
** the air is then heating up, resulting in the air expanding and the piston being further pushed away from the heat source
* Phase 4 (bottom dead centre)
** when the piston reaches bottom dead centre, the exhaust valve is open, releasing the build up pressure and hot air.
** the flywheel keeps the piston moving
Differences from Stirling engines
Stirling engines are typically closed systems, while Manson engines are open systems.[ The displacer and work piston of the Manson engine have zero phase angle.][
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Variations
* Manson-Guise Engine
A Manson-Guise engine is a simplified, albeit less powerful version of a Manson engine. It is a type of hot air engine, converting a temperature difference into motion. There is a hot side and a cold side to the engine. Providing there is a la ...
The valves and gas paths are considered by some to be complicated to manufacture, so various variants exist with improved, modified, or simplified valves and gas paths.[
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Sources
{{Heat engines
Hot air engines