Shallow Water Ship Hydrodynamics

1985 ◽  
pp. 89-129
Author(s):  
R. Timman ◽  
A. J. Hermans ◽  
G. C. Hsiao
Keyword(s):  
Shallow Water ◽  
Ship Hydrodynamics

A Numerical Method for Calculation of Ship–Ship Hydrodynamics Interaction in Shallow Water Accounting for Sinkage and Trim

2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Huilong Ren ◽  
Chen Xu ◽  
Xueqian Zhou ◽  
Serge Sutulo ◽  
Carlos Guedes Soares
Keyword(s):  
Shallow Water ◽  
Hydrodynamic Interaction ◽  
Mirror Image ◽  
Image Method ◽  
Interaction Forces ◽  
Ship Hydrodynamics ◽  
Time Simulation ◽  
Water Accounting ◽  
Ship Hydrodynamic ◽  
Sinkage And Trim

Abstract Sinkage and trim, which often occur to ships moving in shallow water, do not only have an effect on the ship–ship hydrodynamic interaction forces but also increase the risk of grounding. Potential flow-based online calculation of ship–ship hydrodynamic interaction forces without accounting for dynamic sinkage and trim is able to capture the hydrodynamic interaction effects with fair accuracy; however, there are still discrepancies in many cases, especially in the case of shallow water. An algorithm based on the potential theory has been devised for real-time simulation of the hydrodynamic interaction between two ships in shallow water accounting for sinkage and trim. The shallow water condition is modeled using the mirror image method. The sinkage and trim are solved iteratively based on the principle of hydrodynamic balance, where a mesh trimming procedure is carried out when the waterline is changed. Simulations are performed with and without accounting for the sinkage and trim, and comparison with experimental results shows a fair agreement.

ShallowFlow: A Program to Model Ship Hydrodynamics in Shallow Water

2014 ◽  
Author(s):  
Tim P. Gourlay
Keyword(s):  
Shallow Water ◽  
Cross Section ◽  
Hydrodynamic Pressure ◽  
Open Water ◽  
Arbitrary Cross Section ◽  
Far Field ◽  
Shallow Water Theory ◽  
Ship Hydrodynamics ◽  
Cruise Ships ◽  
Sinkage And Trim

In this article we present details of “ShallowFlow”, a computer program to model the hydrodynamic flow around ships in calm shallow water. The program is based on slender-body shallow-water theory. Outputs from the program include far-field hydrodynamic pressure and flow velocities; free surface drawdown; sinkage and trim. Varying transverse bathymetry including open water, dredged channels, and canals of arbitrary cross-section may be modelled. The method is best suited to displacement ships, including cargo ships, ferries, cruise ships, warships and superyachts.

Spatial assemblage structure of shallow-water reef fish in Southwest Australia

2020 ◽  
Vol 649 ◽  
pp. 125-140
Author(s):  
DS Goldsworthy ◽  
BJ Saunders ◽  
JRC Parker ◽  
ES Harvey
Keyword(s):  
Shallow Water ◽  
Reef Fish ◽  
Marine Environment ◽  
Fish Assemblages ◽  
Canopy Cover ◽  
Reef Fishes ◽  
Reef Fish Assemblage ◽  
Reef Type ◽  
Present Distribution ◽  
Southwest Australia

Bioregional categorisation of the Australian marine environment is essential to conserve and manage entire ecosystems, including the biota and associated habitats. It is important that these regions are optimally positioned to effectively plan for the protection of distinct assemblages. Recent climatic variation and changes to the marine environment in Southwest Australia (SWA) have resulted in shifts in species ranges and changes to the composition of marine assemblages. The goal of this study was to determine if the current bioregionalisation of SWA accurately represents the present distribution of shallow-water reef fishes across 2000 km of its subtropical and temperate coastline. Data was collected in 2015 using diver-operated underwater stereo-video surveys from 7 regions between Port Gregory (north of Geraldton) to the east of Esperance. This study indicated that (1) the shallow-water reef fish of SWA formed 4 distinct assemblages along the coast: one Midwestern, one Central and 2 Southern Assemblages; (2) differences between these fish assemblages were primarily driven by sea surface temperature, Ecklonia radiata cover, non-E. radiata (canopy) cover, understorey algae cover, reef type and reef height; and (3) each of the 4 assemblages were characterised by a high number of short-range Australian and Western Australian endemic species. The findings from this study suggest that 4, rather than the existing 3 bioregions would more effectively capture the shallow-water reef fish assemblage patterns, with boundaries having shifted southwards likely associated with ocean warming.

Low mode acoustics of shallow water waveguides

2011 ◽  
Vol 181 (11) ◽  
pp. 1222 ◽  
Author(s):  
Aleksandr G. Luchinin ◽  
Aleksandr I. Khil'ko
Keyword(s):  
Shallow Water
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