Some Considerations on the Reaction of Wind Upon Sails

1938 ◽  
Vol 42 (334) ◽  
pp. 867-871 ◽  
Author(s):  
J. T. C. Moore-Brabazon
Keyword(s):  
New Jersey ◽  
Model Tests ◽  
Towing Tank ◽  
Stevens Institute ◽  
Institute Of Technology ◽  
General Configuration ◽  
Sailing Boat

The study of the problems connected with a successful racing sailing boat, like Gaul, can be divided into three parts. There is first of all the general configuration of the hull upon which lately much study has been directed. Anybody interested in this should look up the article, “Model Tests of Sailing Yachts,” by Kenneth S. M. Davidson, Director, Experimental Towing Tank, Stevens Institute of Technology, New Jersey, appearing in the August issue of “The Rudder,” in which it will be noted model hulls are pulled through the tank at an angle of heel, and with an angle of drift.

Experimental Investigation of FPSO Roll Motion Response Coupled with Sloshing in a Pair of Two Row Cargo Tanks

2021 ◽  
Author(s):  
Jane-Frances Igbadumhe ◽  
Mirjam Furth ◽  
Jack Bonoli ◽  
John Dzielski
Keyword(s):  
Roll Motion ◽  
High Demand ◽  
Towing Tank ◽  
Motion Response ◽  
Model Response ◽  
Stevens Institute ◽  
Time Histories ◽  
Early Production ◽  
Institute Of Technology ◽  
Continuous Loading

Abstract Floating Production Storage and Offloading Units (FPSOs) will continue to be in high demand because of their numerous advantages; such as, their ability to offer early production and operate in ultra-deep water locations, while remaining easy to relocate to meet changing needs. By design, slack cargo tanks are almost always present in FPSOs due to continuous loading and offloading operations; however, the presence of slack cargo impacts the seakeeping stability abilities of FPSOs. There are limited published experimental data on coupled sloshing with seakeeping of stationary vessels, and existing studies on this have focused on single row cargo tanks which is seldom the case in FPSOs. The aim of this paper is to study roll motion coupled with sloshing in partially-filled pair of two-row tanks of a stationary FPSO model exposed to regular beam waves. The model tests was performed in the Davidson Laboratory towing tank at Stevens Institute of Technology. The FPSO model response in roll was measured, and the time histories of sloshing oscillation were measured on the starboard and port side of one of the stern cargo tanks. The results show that varying internal cargo sloshing leads to unpredictable motion response of floating vessels that should be accounted for in the design and offloading operations of FPSO.

Seakeeping Evaluation of a Tri-SWACH Based on CFD Calculations and Model Tests

2021 ◽  
Author(s):  
Gong Xiang ◽  
Raju Datla ◽  
Xianbo Xiang
Keyword(s):  
Time Domain ◽  
High Speed ◽  
Three Dimensional ◽  
Primary Objective ◽  
Model Tests ◽  
Numerical Predictions ◽  
Seakeeping Performance ◽  
Stevens Institute ◽  
Transverse Stability ◽  
Institute Of Technology

AEGIR is a time-domain seakeeping CFD code that uses an advanced, high-order boundary element method (BEM) to solve the three-dimensional potential-flow and has been developed for several years. In this paper, the latest version of AEGIR is used to predict the seakeeping of the Tri-SWACH with and without side hulls in headsea regular waves respectively. The primary objective was to evaluate its accuracy of predicting seakeeping performance of the Tri-SWACH under regular headsea waves in AEGIR. A series of simulated time domain heave and pitch responses for Tri-SWACH with and without side hulls via AEGIR have been compared with corresponding model tests conducted in the high speed towing tank in Davidson Lab, Stevens Institute of Technology. A good agreement in terms of heave and pitch responses between AEGIR numerical predictions and experimental data shows the seakeeping prediction capability of AEGIR for Tri-SWACH Preliminary Design. Also, the simulated seakeeping of a Tri-SWACH is compared with a Tri-SWACH center hull. It is found that the effects of side hulls will increase the transverse stability of the Tri-SWACH without causing additional significant effect on the seakeeping performance of the Tri-SWACH.

Selecting a Keel Appendage for a Cruising Yacht From a Standard Keel Series

1979 ◽  
Author(s):  
Deborah W. Berman
Keyword(s):  
Aspect Ratio ◽  
Model Tests ◽  
Thickness Ratio ◽  
Model Data ◽  
Standard Series ◽  
Stevens Institute ◽  
Form Part ◽  
Institute Of Technology

The purpose of this paper is to describe the results of model tests for a series of three keels; two at constant draft; two at constant aspect ratio; all at constant taper ratio and thickness ratio. These keels form part of a standard series developed by Pierre De Saix at Davidson Laboratory, Stevens Institute of Technology in 1974 and originally tested on a 5.5 meter hull (1). The three keels were all tested on the model of a small cruising yacht over a range of heel angles, leeways and speeds. An analysis is made of the expanded model data and a comparison presented of the forces and moments operating on the deepest keel and the two keels of constant draft.

Study on vertical motion reduction of a trimaran based on collaborative controlled appendages

2020 ◽  
Vol 17 (6) ◽  
pp. 172988142097677
Author(s):  
Zhilin Liu ◽  
Linhe Zheng ◽  
Guosheng Li ◽  
Shouzheng Yuan ◽  
Songbai Yang
Keyword(s):  
Experimental Study ◽  
Vertical Motion ◽  
Model Tests ◽  
Wave Period ◽  
Regular Waves ◽  
Towing Tank ◽  
Vertical Stability ◽  
Stabilization Control ◽  
Stability Performance

In recent years, the trimaran as a novel ship has been greatly developed. The subsequent large vertical motion needs to be studied and resolved. In this article, an experimental study for a trimaran vertical stabilization control is carried out. Three modes including the bare trimaran (the trimaran without appendages, the trimaran with fixed appendages, and the trimaran with controlled appendages) are performed through model tests in a towing tank. The model tests are performed in regular waves. The range of wave period is 2.0–4.0 s, and the speed of the carriage is 2.93 and 6.51 m/s. The results of the three modes show the fixed appendages and the actively controlled appendages are all effective for the vertical motion reduction of the trimaran. Moreover, the controlled appendages are more effective for the vertical stability performance of the trimaran.

Experimental Study of a Tanker Ship Squat in Shallow Water

2014 ◽  
Vol 66 (2) ◽  
Author(s):  
Mohammadreza Fathi Kazerooni ◽  
Mohammad Saeed Seif
Keyword(s):  
Experimental Study ◽  
Shallow Water ◽  
Experimental Approach ◽  
Model Tests ◽  
Ship Hull ◽  
Experimental Results ◽  
Shallow Waters ◽  
Towing Tank ◽  
Ship Model

One of the phenomena restricting the tanker navigation in shallow waters is reduction of under keel clearance in the terms of sinkage and dynamic trim that is called squatting. According to the complexity of flow around ship hull, one of the best methods to predict the ship squat is experimental approach based on model tests in the towing tank. In this study model tests for tanker ship model had been held in the towing tank and squat of the model are measured and analyzed. Based on experimental results suitable formulae for prediction of these types of ship squat in fairways are obtained.

On The Hydrodynamics Of A Skiff At Different Crew Positions

2013 ◽  
Author(s):  
Ignazio Maria Viola ◽  
Joshua Enlander
Keyword(s):  
Uncertainty Analysis ◽  
High Performance ◽  
Olympic Games ◽  
Towing Tank ◽  
Lower Resistance ◽  
Model Scale ◽  
Sailing Boat ◽  
Large Vessels

A set of towing tank tests was undertaken on a 1:4-model-scale high-performance small sailing boat, which was a candidate for the 2016 Olympic games. The resistance, sink and trim were measured and uncertainty analysis was completed. The boat was tested for different longitudinal positions of the crew in displacement, transition and fully planning regimes. The resistance measurements in the towing tank were well correlated with established empirical formulations developed for planning hulls. It was found that at low Froude numbers, forward crew positions allow lower resistance and resistance increases significantly for after crew positions, while at higher Froude numbers after positions allow lower resistance, and the resistance is less sensible to the crew position. These findings are in agreement with sailor experience and with measurements performed by other authors on large vessels.

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