scholarly journals Analysis of Japan Coastal Winds and Waves and Freeboard of Small Ship

2017 ◽  
Vol 137 (0) ◽  
pp. 1-8
Author(s):  
Takako KURODA ◽  
Harukuni TAGUCHI ◽  
Masaru TSUJIMOTO
Keyword(s):  
Coastal Winds ◽  
Small Ship

Experimental Performance of a Trochoidal Propeller with High-Aspect-Ratio Blades

1989 ◽  
Vol 26 (03) ◽  
pp. 192-201 ◽  
Author(s):  
Neil Bose ◽  
Peter S. K. Lai
Keyword(s):  
Aspect Ratio ◽  
High Efficiency ◽  
Open Water ◽  
Finite Amplitude ◽  
Dynamic Stall ◽  
Frictional Drag ◽  
Overall Performance ◽  
Small Ship ◽  
Propeller Performance ◽  
Thrust And Torque

Open-water experiments were done on a model of a cycloidal-type propeller with a trochoidal blade motion. This propeller had three blades with an aspect ratio of 10. These experiments included the measurement of thrust and torque of the propeller over a range of advance ratios. Tests were done for forward and reverse operation, and at zero speed (the bollard pull condition). Results from these tests are presented and compared with: a multiple stream-tube theoretical prediction of the performance of the propeller; and a prediction of the performance of a single blade of the propeller, oscillating in heave and pitch, using unsteady small-amplitude hydrofoil theory with corrections for finite amplitude motion, finite span, and frictional drag. At present, neither of these theories gives a completely accurate prediction of propeller performance over the whole range of advance ratios, but a combination of these approaches, with an allowance for dynamic stall of the blades, should lead to a reliable simple theory for overall performance prediction. Application of a propeller of this type to a small ship is discussed. The aim of the design is to produce a lightly loaded propeller with a high efficiency of propulsion.

scholarly journals Hydrodynamics characteristics of the small ships rudders

2020 ◽  
Vol 43 ◽  
pp. 21-26
Author(s):  
Dan Obreja
Keyword(s):  
Design Process ◽  
Computer Code ◽  
Short Description ◽  
Research Centre ◽  
Research Activities ◽  
Optimum Position ◽  
Practical Research ◽  
Small Ship ◽  
Control Forces ◽  
Selection Of

The estimation of the hydrodynamics characteristics of the small ships rudders is an important issue in the initial design process. The manoeuvring performance depends on the type and geometry of the rudder. The control forces and moments generated by the rudder deflection can be calculated on the basis of the hydrodynamics characteristics of the rudder. A short description of the Mordvinov theoretical model is presented in this paper, in order to determine the hydrodynamics characteristics of a small ship rudder, with the propeller and hull influences. On the basis of the control forces and moments, the optimum position of the rudder stock and the selection of the steering gear can be performed. Using the Mordvinov method, the computer code PHP NM-MAN-HC was develop at the Research Centre of the Naval Architecture Faculty of “Dunarea de Jos” University of Galati. This computer code is integrated in the software platform PHP (Preliminary Hydrodynamics Performance) and is used for didactic applications and practical research activities in the small ship design process

scholarly journals Coastal winds drive a recruitment mechanism for estuarine fisheries

2020 ◽  
Author(s):  
Hayden T. Schilling ◽  
Charles Hinchliffe ◽  
Jonathan P. Gillson ◽  
Anthony Miskiewicz ◽  
Iain M. Suthers
Keyword(s):  
Larval Fish ◽  
Future Research ◽  
Larval Abundance ◽  
Spawning Period ◽  
Onshore Wind ◽  
Larval Recruitment ◽  
Australian Region ◽  
Coastal Winds ◽  
Key Driver ◽  
Catch Rates

AbstractCoastal winds transport larval fish onshore or offshore which may contribute to estuarine recruitment, yet our understanding of the mechanism underlying this relationship is limited. Here, we show that larval abundance of coastally spawned species increased with weak to moderate upwelling favourable winds 14 days prior to sampling, reflecting increased nutrient and plankton availability for larval fish. A strong decline in larval abundance was observed following strong upwelling favourable winds while abundance increased with onshore (downwelling favourable) winds, in relation to offshore and onshore wind-driven transport. Subsequently, we show that effects of wind during the spawning period can be detected in lagged estuarine commercial fisheries catch rates of coastally spawned species (lagged by 2 – 8 years depending on species’ growth rates), representing the same mechanism proposed for larval fish. Upwelling favourable winds in the southeast Australian region have increased since 1850 while onshore winds have decreased, which may reduce larval recruitment to estuaries. Coastal winds are likely an important factor for estuarine recruitment in the east Australian region and future research on the estuarine recruitment of fish should incorporate coastal winds. As global winds are changing, it is important to investigate if this mechanism is applicable to other regions around the world where coastal winds are a key driver of upwelling.

scholarly journals Safety Consciousness and Problem of Small Ship Operator in the Coast Area

1993 ◽  
Vol 89 (0) ◽  
pp. 109-120
Author(s):  
Kiyoshi AMAGAI ◽  
Nobuo KIMURA ◽  
Tsukasa HOKIMOTO
Keyword(s):  
Small Ship

scholarly journals Simulation of coastal winds along the central west coast of India using the MM5 mesoscale model

2010 ◽  
Vol 109 (3-4) ◽  
pp. 91-106 ◽  
Author(s):  
Dhanya Pushpadas ◽  
P. Vethamony ◽  
K. Sudheesh ◽  
Smitha George ◽  
M. T. Babu ◽  
...  
Keyword(s):  
West Coast ◽  
Mesoscale Model ◽  
West Coast Of India ◽  
Coastal Winds

Detection of small ship targets from an optical remote sensing image

2018 ◽  
Vol 11 (3) ◽  
pp. 275-284 ◽  
Author(s):  
Mingzhu Song ◽  
Hongsong Qu ◽  
Guixiang Zhang ◽  
Guang Jin
Keyword(s):  
Remote Sensing ◽  
Remote Sensing Image ◽  
Optical Remote Sensing ◽  
Optical Remote Sensing Image ◽  
Small Ship

Analysis of SWATH Ship Structures

1998 ◽  
Vol 35 (02) ◽  
pp. 85-97
Author(s):  
Kwok Fai Cheung ◽  
Ludwig H. Seidl ◽  
Suqin Wang
Keyword(s):  
Comparative Study ◽  
Primary Structure ◽  
Ship Structures ◽  
Methods Of Analysis ◽  
Small Ship

Three methods of analysis of the primary structure of SWATH ships are examined. The quasistatic, rigid-dynamic and hydroelastic approaches are applied to analyze the structure of a detailed SWATH design. Deflections and stresses are calculated after each method and compared. The convergence of the hydroelastic approach with respect to the number of modes is also investigated. Although a relatively small ship is considered in this comparative study, hydroelastic effects are shown to be significant in areas of greater flexibility.

All Should be “A” Teams

2019 ◽  
pp. 150-168
Author(s):  
James Goldrick
Keyword(s):  
Training System ◽  
Training Experience ◽  
The Creation ◽  
Collective Efficiency ◽  
Small Ship ◽  
The Right ◽  
Scarcity Of Resources ◽  
And Training ◽  
Experienced Personnel

This chapter by James Goldrick examines the creation of a sophisticated learning and training system for the anti-U-boat war, which is one of the most significant elements of the Atlantic campaign, critical to the effectiveness of the escort units of the RN and RCN. This system's development took place as both services were forced to adapt rapidly to profound changes in their operational environments. That development faced many challenges, not only from a scarcity of resources, but from the necessity to develop sufficient understanding of the problem. The "master-apprentice" culture of professionalization managed through long service would not serve under the pressure of the oceanic small-ship war. The effort had to be industrialized. Acceptable levels of collective efficiency only became possible when the right equipment and training assets, sufficiently – even if barely – experienced personnel, and proven tactical doctrine could be brought together to provide the necessary fidelity within the training experience. From the outset, this would always be a much more complex and resource-intensive operation than the straightforward working-up of individual units.

Deep learning for autonomous ship-oriented small ship detection

2020 ◽  
Vol 130 ◽  
pp. 104812 ◽  
Author(s):  
Zhijun Chen ◽  
Depeng Chen ◽  
Yishi Zhang ◽  
Xiaozhao Cheng ◽  
Mingyang Zhang ◽  
...  
Keyword(s):  
Deep Learning ◽  
Ship Detection ◽  
Small Ship ◽  
Autonomous Ship
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