Flow field around Coandă effect-based polymetallic-nodule collector

Insights from three-dimensional numerical simulations

Journal Article (2026)
Author(s)

Lalit Kumar (TU Delft - Mechanical Engineering)

Sebastiaan Mulders (TU Delft - Mechanical Engineering)

Said Alhaddad (TU Delft - Mechanical Engineering)

Research Group
Offshore and Dredging Engineering
DOI related publication
https://doi.org/10.1016/j.apor.2026.105032 Final published version
More Info
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Publication Year
2026
Language
English
Research Group
Offshore and Dredging Engineering
Journal title
Applied Ocean Research
Volume number
170
Article number
105032
Downloads counter
37
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Abstract

Recent advancements have demonstrated that collectors based on the Coandă effect can effectively harvest polymetallic nodules from the seabed. However, the hydrodynamics of the flow around such collectors, particularly the mechanisms of ambient water entrainment, remain insufficiently explored. To address this gap, we performed three-dimensional numerical simulations to investigate the flow characteristics surrounding a Coandă effect-based collector, focusing on the effects of main jet velocity, secondary jet velocity, radius of curvature, and bottom clearance. The results show that increasing the main jet velocity enhances flow attachment and strengthens the pressure gradients beneath the collector, thereby increasing the entrainment of ambient water into the collection duct. Similarly, higher secondary jet velocities improve flow attachment and raise the collection duct flow rate but also lead to greater sideways water spillage. Furthermore, a larger radius of curvature reduces sideways spillage, consequently promoting greater ambient water entrainment beneath the collector. Likewise, increasing the bottom clearance enhances ambient water entrainment. Overall, these findings provide valuable insights for optimizing the operational parameters of Coandă effect-based collectors to maximize collection efficiency while minimizing water spillage.