Print Email Facebook Twitter Sediment Erosion Generated by a Coandă-Effect-Based Polymetallic-Nodule Collector Title Sediment Erosion Generated by a Coandă-Effect-Based Polymetallic-Nodule Collector Author Alhaddad, S.M.S. (TU Delft Offshore and Dredging Engineering) Helmons, R.L.J. (TU Delft Offshore and Dredging Engineering; Norwegian University of Science and Technology (NTNU)) Date 2023 Abstract To date, hydraulic collection is the most widely considered technology in polymetallic-nodule mining, since there is no direct contact between hydraulic collectors and ocean floor. To construct a hydraulic collector that results in the least sediment disturbance, it is critical to develop an insightful understanding of the interaction between the collector and sediment bed. To this end, we conducted a set of small-scale experiments in which several operational conditions were tested, delivering the first quantitative data for sediment erosion resulting from a hydraulic collector driving over a sand bed. This paper presents and discusses the experimental results and observations. It is found that the collector’s forward velocity is inversely proportional to the bed-sediment erosion depth, since the bed is exposed to the flow for a longer time when the collector drives slower and vice versa. In contrast, an increased jet velocity leads to a larger erosion depth. Furthermore, when the collector underside is nearer to the sediment bed, a larger sediment layer is exposed to the water flow, resulting in a larger erosion depth. Finally, the experimental results show that collector water jets strike the sediment bed under an inclined angle, destabilizing the upper sediment layer and consequently dragging sediment particles along toward the collection duct and behind the collector head. This study improves the predictability of sediment erosion created by Coandă-effect-based collectors, which is a crucial asset to optimize the collector design and decrease the extent of the associated sediment plumes. Subject Sediment erosionDeep sea miningPolymetallic nodulesHydraulic collectorCoandă effectJetting To reference this document use: http://resolver.tudelft.nl/uuid:ef9ec5cb-a68c-4ec0-a520-96662f42e43e DOI https://doi.org/10.3390/jmse11020349 ISSN 2077-1312 Source Journal of Marine Science and Engineering, 11 (2) Part of collection Institutional Repository Document type journal article Rights © 2023 S.M.S. Alhaddad, R.L.J. Helmons Files PDF jmse_11_00349.pdf 13.17 MB Close viewer /islandora/object/uuid:ef9ec5cb-a68c-4ec0-a520-96662f42e43e/datastream/OBJ/view