Design and analysis of cable-connected metallic bellows as Variable Buoyancy Modules

Design of a variable buoyancy system with metallic bellows for underwater applications is presented here. Metallic bellow with a Linear Actuator is proposed as the Variable Buoyancy module. The metallic bellow is approximated as a cylinder and modelled mathematically to study the behavior of the module underwater. The response of the system at different initial orientation and the velocity of the system at different positive buoyancy are studied. The dynamics of the module, when anchored to an underwater platform- and the motion characteristics of the module with various buoyancy levels are studied. Two similar modules are then cascaded one above the other and their performance is analyzed with alternative sequence of actuation.