Buoyancy engine

Diagram of how a Buoyancy Engine works

A buoyancy engine is a device that alters the buoyancy of a vehicle or object in order to either move it vertically, as in the case of underwater profiling floats and stealth buoys, or provide forward motion (therefore providing variable-buoyancy propulsion) such as with underwater gliders and some autonomous aircraft.[1][2]

For underwater applications, buoyancy engines typically involve a hydraulic pump that either inflates and deflates an external bladder filled with hydraulic fluid, or extends and retracts a rigid plunger. The change in the vehicle's total volume alters its buoyancy, making it float upwards or sink as required.[1] Alternative systems employing gas obtained from water electrolysis, rather than hydraulic fluid, have also been proposed,[2] as have systems which pump ambient water into and out of a pressure vessel.[3]

  1. ^ a b Kobayashi, Taiyo; Asakawa, Kenichi; Ino, Tetsuro (2010). New Buoyancy Engine for Autonomous Vehicles Observing Deeper Oceans. Proceedings of the Twentieth (2010) International Offshore and Polar Engineering Conference. Retrieved 22 May 2019.
  2. ^ a b Cameron, Colin G. (October 2005). "The WET Buoyancy Engine" (PDF). Defence Research and Development Canada. p. 1. Archived from the original (PDF) on 16 September 2022. Retrieved 22 May 2019.
  3. ^ Worall, Mark; Jamieson, A.J.; Holford, A.; Neilson, R.D.; Player, Michael; Bagley, Phil (July 2007). A variable buoyancy system for deep ocean vehicles. OCEANS 2007 - Europe. doi:10.1109/OCEANSE.2007.4302317 – via Researchgate.