Can smoothed particle hydrodynamics simulate physically realistic movements of underwater vehicles?

AbstractThis work presents the first results using Smoothed Particle Hydrodynamics (SPH), a mesh-free technique, to simulate underwater vehicle motion with the goal of achieving sufficient physical realism and computation time performance capabilities. The objective is not to get very accurate values for the hydrodynamic parameters, but to show that SPH can simulate hydrodynamic parameters with the same order of magnitude as the reference, in order to allow a realistic control of robots in water. First, spherical objects are simulated to check buoyancy realism, speed limit existence, and hydrodynamic parameters in comparison with reference values. Then, horizontal and vertical movements of a capsule-shape object and a real torpedo-shape underwater robot are compared. The results show that buoyancy is respected, and that spherical objects reach a speed limit in accordance with the laws of physics. In addition, added-mass is simulated with 20 % variation on average with respect to the reference and varies homothetically with respect to the object's size. In contrast, drag forces cannot not be simulated with the same level of realism without reducing the particle size, which makes the simulation last longer. SPH for underwater robotics simulation appears to be promising, and ways of further improvements are being considered.Keywords: Fluid-solid interactionunderwater roboticssmoothed particle hydrodynamicshydrodynamic parameterscomputational fluid dynamics AcknowledgmentsThis work is a result of the collaboration of Centroid LAB Inc. (Los Angeles, USA), which develops the Neutrino software, and the Laboratoire COSMER (Toulon, France).Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingThis work was partly supported by the Direction Générale de l'Armement, DGA RAPID grant in partnership with SUBSEA-TECH (Marseille, France) and ROBOPEC (Six-Fours-les-Plages, France).Notes on contributorsNicolas GartnerNicolas Gartner received his Master's degree in Engineering from SIGMA Clermont in 2016, formerly Institut Français de Mécanique Avancée, and his PhD degree from the University of Toulon in 2020. This research was conducted during his postdoc at the University of Toulon. He currently serves the Centre Technologique Méditerranéen de Métrologie. His research work is focused on underwater robotics and the evaluation of hydrodynamics performance using fluid simulation techniques like SPH.Niels MontanariNiels Montanari holds Master's degrees in computer science, applied mathematics and environmental physics, from the Bordeaux Institute of Technology, Grenoble-Alpes University and Paris-Saclay University, respectively. Since 2015, he has worked for Centroid LAB as a simulation & software engineer, performing research and development work on mesh-free particle-based methods for simulating fluid flows in various industry applications.Mathieu RichierMathieu Richier graduated from the Ecole Nationale Supérieure d'Ingénieur de Limoges in 2005 with a degree in mechatronics. He finished his PhD in 2013 at IRSTEA / University of Clermont Auvergne. In 2014, he joined the University of Toulon as an Associate Professor. His research focuses on hydrodynamic modeling, the implementation of observation algorithms and the development of mechatronic systems for underwater vehicles.Vincent HugelVincent Hugel received the Ph.D. degree in robotics from the University of Paris VI, and the Robotics Research degree from the University of Versailles, France, in 1999, and 2007, respectively. Since 2014, he is a Full Professor at the University of Toulon and leads the Cosmer Lab (Design of robotic systems), Toulon, France, where he is conducting research on autonomous robots and underwater vehicles.Ramprasad SampathRamprasad Sampath received his Msc in computer science from the Birla Institute of Technology and Science in 1992 and the University of South Carolina in 1995. During the years 1995–2013, he worked in different visual effects studios as a Technical Director and Senior Technical Director. Since 2013 he has been working at Centroid LAB and is currently CEO and Director of Research Development. His work mainly focuses on particle fluid simulation and fire simulations.