Open Access Repository
Aquaculture net drag and added mass
Downloads
Downloads per month over past year
![]() |
PDF
Aquaculture_Net...pdf | Request a copy Full text restricted Available under University of Tasmania Standard License. |
Abstract
The hydrodynamic loads on plane net samples of differing mesh geometry are measured in steady and oscillating flows. The steady loads on plane nets are also numerically simulated. The net is modeled as an inter-connected system of lumped masses and springs. The loads are computed for each twine segment and applied to the lumped masses at the segment ends. The equations of motion are formulated for the coupled dynamics of the masses and solved numerically. Drag data from the experiments is compared with analytical and numerical models and existing empirical formulae. Results for steady flows indicate that drag coefficients for nets and cylinders, as a function of the Reynolds number, have identical trends with consistent offsets. It is concluded that the drag coefficient for nets is equivalent to the drag coefficient for cylinders (and spheres for knotted nets) modified by a function of net solidity. For unsteady flows, the drag and added mass are extracted from the total wave force by applying a vector approach. It is shown that drag and added mass coefficients are not well quantified by conventional non-dimensional parameters (i.e. Keulegan–Carpenter and Reynolds numbers). The unsteady drag coefficient is presented as a function of wave particle velocity, wave period and net porosity. It is proposed that the added mass coefficient be expressed by an assumption of an effective thickness—conceptually the width of water affected by the net, which is a function of wave frequency and net solidity.
Item Type: | Article |
---|---|
Authors/Creators: | Balash, C and Colbourne, B and Bose, N and Raman-Nair, W |
Keywords: | Plane nets; Steady current; Harmonic waves |
Journal or Publication Title: | Aquacultural Engineering |
ISSN: | 0144-8609 |
DOI / ID Number: | 10.1016/j.aquaeng.2009.04.003 |
Additional Information: | The definitive version is available at http://www.sciencedirect.com |
Item Statistics: | View statistics for this item |
Actions (login required)
![]() |
Item Control Page |