Abstract No.F180128-139

Author name(s): Kirill Rozhdestvensky

Company: Saint-Petersburg State Marine Technical University, Russia

Both underwater and wave gliders are known as autonomous unmanned energy-saving vehicles which have recently found applications for monitoring of the world ocean. The paper discusses simplified mathematical models of these platforms enabling straightforward parametric investigation into relationships between their parameters and performance. In its first part the paper discusses equations describing the motion of an underwater glider (UG) in vertical plane as a basis of derivations relating geometric, kinematic and hydrodynamic characteristics of UG and its lifting system with relative buoyancy and pitch angle. Obtained therewith are formulae for estimation of the UG glide path speed, lift-to-drag ratio, range of navigation and endurance. The second part of the paper is dedicated to estimation of thrust and speed of a wave glider (WG), comprising a surface module (“raft”) and underwater module represented by a wing, with use of a simplified mathematical modeling intended to clarify the influence of parameters upon performance of the WG. The derivations led to an equation of forced oscillations of the vehicle accounting for interaction of the upper and lower modules, connected by a “rigid” umbilical. The exciting impact of progressive waves of given length and amplitude is found through calculation of variation of a buoyancy force in accordance with Froude-Krylov hypothesis. The derivatives of time varying lift with respect to kinematic parameters, entering the equation of vertical motion of the WG, as well as coefficients of instantaneous and time-averaged thrust force, are found from oscillating hydrofoil theory.

KEY WORDS: autonomous unmanned underwater vehicles; underwater glider

All Rights Reserved. If you need the entire text, please contact the author or intl.exchange@ssnaoe.org