Quantifying the manoeuvring performance of an underwater glider using the RANS-based method

Underwater gliders are long-endurance vehicles that map the ocean using sawtooth trajectories, playing a key role in monitoring oceanic conditions. However, their limited manoeuvrability hinders performance in constrained environments and harsh conditions such as strong ocean currents and waves. Analysing their manoeuvring capabilities can help to unlock their full potential. Recent advancements in Computational Fluid Dynamics (CFD) have enabled a more comprehensive analysis of glider manoeuvrability beyond traditional mathematical models. This study investigates the manoeuvring performance of the Petrel-II glider using the Reynolds-Averaged Navier-Stokes (RANS) method. A computationally efficient numerical approach is developed to control ballasting and the linear and angular movements of the eccentric mass, allowing for adjustments to the glider’s pitch and roll angles to replicate real-time operations. The glider’s saw-tooth and spiral manoeuvres are analysed separately for descent and ascent scenarios using a moving domain method. Pitch angle, surge speed, yaw rate, turning radius, and depth per turn are identified as key parameters governing manoeuvrability. The results provide insights into the Petrel-II glider’s manoeuvrability within physical constraints, identifying optimal control inputs for different operating conditions. The proposed methodology demonstrates the ability to simulate manoeuvring trajectories of gliders with complex geometries and to account for various environmental loads.