Session: 08-06-01 non-presentations

Paper Number: 125269

125269 - Numerical Simulation of the Ocean Cleanup Systems Using Flexible Net 

The Ocean Cleanup has made significant strides in addressing plastic pollution in the Great Pacific Garbage Patch (GPGP). In the context of The Ocean Cleanup, the primary motivators for the project are engineering efficiency and environmental impact which are quantified as Key Performance Indicators (KPIs): the cost per kilogram of extracted plastic and the CO2 emissions per kilogram of extracted plastic. As a Non-profit organization, The Ocean Cleanup is committed to optimizing the usage received donations, especially in its upscaling program. However, the successful upscale of this endeavour necessitates a deeper comprehension of the cleanup system's hydrodynamics.  To tackle this, we introduced a Digital Twin for real-time decisions using accurate physics combined with our offshore GPGP data that is built on Orcaflex but enriched from micro-scale twine-resolved Direct Numerical Simulation (DNS) of flat nets and full-scale experiments carried out in the GPGP. In its current state, our CFD-enriched Digital Twin has an accuracy of less than 15% at nominal span and wide span during operational modes. At very narrow span the discrepancy is higher (~43%) necessitating more physics that are not taken into account. In this work, we incorporate the missing physics such as bending, stretching, and twisting under realistic static and cyclic loads augmenting our DT by integrating  a flexible net formulated from dispersed bonded masses coupled with the locally averaged Navier–Stokes equations, known as DEM-CFD for Discrete Element Method-Computational Fluid Dynamics . This approach allows rigid masses to be bonded creating the twines of the net using simple contact models. Whereas, the Eulerian phase is averaged on cells with the same order of magnitude as the masses diameter.  Additionally, freely moving DEM particles can interact with the net of the cleanup system favouring the quantification of its efficiency. Their motion is governed by Newton's laws applied to every mass considering the fluid in which they are immersed.  

Presenting Author: Andriarimina Rakotonirina The Ocean Cleanup

Presenting Author Biography: Computational Modelling Specialist at The Ocean Cleanup
Post-doc in Computational Multiphase Flow
PhD Student in Computational Multiphase Flow
Master in Fluid Dynamics
Bachelor in Physics

Authors:

Andriarimina Rakotonirina The Ocean Cleanup
Romain Heuillet The Ocean Cleanup
Giovanni Viciconte DCS Computing GmbH
Bruno Sainte-Rose The Ocean Cleanup