This historic engine design burns fuel with compressed air or oxygen and simultaneously sprays fresh or sea water into the combustion chamber. The water flashes into steam, which cools the combustion gases to a temperature the engine metals can survive. The resulting massive expansion of steam and gas drives the pistons or turbines, drastically increasing the engine's efficiency and power output.
The wet heater design gave the Mark 14 torpedo a much longer range than the older dry heater models.
Do not mix it up with
- Dry heater: A dry heater uses only combustion gases without water injection, resulting in less power and lower efficiency.
Related terms
Dry heater
A pneumatic engine design that burns fuel with compressed air or oxygen without injecting water for cooling.
Power
The rate at which work is done or energy is transferred over time.
Cylinder
The tubular chamber in which a piston travels to compress a fluid or convert fluid pressure into mechanical work.