Buoyancy engine

rdf:langString Buoyancy engine

rdf:langString 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. 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. Alternative systems employing gas obtained from water electrolysis, rather than hydraulic fluid, have also been proposed. as have systems which pump ambient water into and out of a pressure vessel