Drag and inertia coefficients of live and surrogate shellfish dropper lines under steady and oscillatory flow

authored by

Jannis Landmann, Lukas Fröhling, Rebekka Gieschen, Bela H. Buck, Kevin Heasman, Nicholas Scott, Malcolm Smeaton, Nils Goseberg, Arndt Hildebrandt

Abstract

Against the background of a drastically increased demand of marine proteins, off-bottom, bivalve aquaculture, provides significant potential for production growth when moved into more energetic marine waters. Hence, research, industry and politics are currently proposing the development of new offshore sites. The highly energetic conditions at these sites present a challenging environment for bivalve aquaculture. In this work, physical experiments of suspended bivalves provide new knowledge on the commonly used design parameters: the drag and inertia coefficients. Live bivalves and manufactured surrogate models at a 1:1 scale were tested in a towing tank as well as under waves. The drag coefficient of live blue mussels was determined to be C

_d = 1.6 for Reynolds numbers between 2.3 × 10

⁴ and 1.4 × 10

⁵. The inertia coefficient obtained from the wave tests was C

_m = 2.1 for Keulegan Carpenter numbers KC < 10. In a pursuit to better understand the differences between live mussels and surrogates in laboratory conditions, the analysis revealed that appropriate surrogates can be identified. A method to determine the characteristic diameter of mussel dropper lines is suggested. The results facilitate the future design of aquaculture systems in high-energy environments and allow for an integration into numerical models.

Organisation(s)

Ludwig-Franzius-Institute of Hydraulics, Estuarine and Coastal Engineering

External Organisation(s)

Technische Universität Braunschweig
Alfred Wegener Institute (AWI) Helmholtz Centre for Polar and Marine Research
Bremerhaven University of Applied Sciences
Cawthron Institute

Type

Article

Journal

Ocean engineering

Volume

235

ISSN

0029-8018

Publication date

01.09.2021

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Ocean Engineering, Environmental Engineering

Sustainable Development Goals

SDG 14 - Life Below Water

Electronic version(s)

https://doi.org/10.1016/j.oceaneng.2021.109377 (Access: Open)