A Novel Experimental Data-Based Modeling Approach for Wave Gliders

Abstract The wave glider is an unmanned autonomous surface vehicle powered by waves, consisting of three main components: the surface float, the tether, and the submarine glider. A high-precision numerical simulation model is an essential tool for predicting the motion performance of wave gliders and optimizing their design parameters. The coupled driving mechanism of the twin-hull structure of the wave glider and the flexible nature of the tether result in multimodal motion characteristics. Moreover, the oscillatory characteristics of the tandem hydrofoils under wave action lead to time-varying, multimodal, and strongly nonlinear fluid loading, while the real-time changes in the flow-facing state of the flexible tether under wave loading result in multimodal motion characteristics. These factors present significant challenges for simulating the wave glider. This article establishes a motion simulation model for the wave glider, which integrates the hydrodynamic coefficients of the submarine glider and the tether measured through experiments. First, the lift and drag coefficients of the submarine glider are measured in a wind tunnel. Subsequently, the drag of the tether is measured in a towing tank. The model is validated through active excitation motion experiments conducted in a towing tank, with the simulation error of the wave glider speed remaining within 5%. Finally, this simulation model is employed to explore the motion and mechanical characteristics of the wave glider under different waves. The results indicate that the simulation model provides technical support for studying the motion characteristics of wave gliders and facilitates their optimization and design.