Model Test Study on Anti-Rolling of Ship at Zero Speed

2020 ◽  
Author(s):  
Yuefeng Wei ◽  
Yi Yang ◽  
Sheming Fan ◽  
Zhen Liu ◽  
Peiyuan Feng
Keyword(s):  
Model Test ◽  
Control Strategy ◽  
Test Results ◽  
Towing Tank ◽  
Irregular Wave ◽  
Test Study ◽  
Rolling Method ◽  
Fin Stabilizer ◽  
Mode A

Abstract Model test is carried out to study the anti-rolling method of ship at zero speed in the present paper. First of all, based on the longitudinal flap mode, a zero speed fin stabilizer is designed. Furthermore, a control strategy for anti-rolling of ship at zero speed is proposed. At last, both regular and irregular wave tests are performed in towing tank. It can be shown from the test results that anti-rolling effectiveness of the zero speed fin stabilizer is obvious. Under level four sea condition, the effectiveness of anti-rolling is more than 40%. And under level five sea condition, the effectiveness of anti-rolling is more than 35%.

UJI TARIK HIDRODINAMIKMODEL KAPAL BERSAYAP WiSE DENGAN LAMBUNG DASAR BERSTEP

2013 ◽  
Vol 12 (3) ◽  
Author(s):  
Iskendar Iskendar ◽  
Andi Jamaludin ◽  
Paulus Indiyono
Keyword(s):  
Comparative Study ◽  
Model Test ◽  
Hydrodynamic Model ◽  
Surface Effect ◽  
Center Of Gravity ◽  
Test Results ◽  
Flat Bottom ◽  
Towing Tank ◽  
Test Models ◽  
Wetted Surface Area

This paper describes hydrodynamic model tests of Wing in Surface Effect (WiSE) Craft. These craft  was fitted with  stephull  form in different location on longitudinal flat bottom (stepedhull planning craft) to determine the influences of sticking and porpoising motion performances. These motions are usually occured when the craft start to take-off from water surfaces. The test models with scale of 1 : 7 were comprised of 4 (four) stephull models and 1 (one) non-stephull model  as a comparative study. The hydrodynamic  tests were performed with craft speed of 16 – 32 knots (prototype values) in Towing Tank at UPT. Balai Pengkajian dan Penelitian Hidrodinamika (BPPH), BPPT, Surabaya. The resistance (drag) was measured by dynamo meter and the trim of model (draft changing at fore and aft  of model due to model speed) was measured by trim meter. By knowing the value of model trim, the wetted surface area can be determined. Then, the lift forces were calculated based on these measured values. The model test results were presented on tables and curves.  Test results show that models  with step located far away from center of gravity of the WiSE craft tend to porpoising and sticking condition, except if the step location on the below of these center of gravity. While model without step tends to sticking conditions.

scholarly journals Effect of water resistance on predictions of ship ice resistance using towing tests in ice basin

2021 ◽  
Vol 4 (398) ◽  
pp. 43-52
Author(s):  
Kirill Sazonov ◽  
◽  
Grigory Kanevsky ◽  
Mikhail Lobachev ◽  
◽  
...  
Keyword(s):  
Test Data ◽  
Model Test ◽  
Hydrodynamic Interaction ◽  
Water Resistance ◽  
Test Results ◽  
Improved Method ◽  
Towing Tank ◽  
Ice Floes ◽  
Ice Resistance

Object and purpose of research. The object under study is a method to determine ice resistance using towing tests of ship models. The purpose of the work is to develop a method that takes into account the water resistance effect on predictions of full-scale ship ice resistance. Materials and methods. The materials for development are model test data and earlier methods for determination of ice resistance on models, as well as recommendations of the International Towing Tank Conference (ITTC). Main results. The method is suggested to take into account the water resistance in analyzing the towing test data obtained in the ice basin, as well as the method for extrapolating the ice resistance due to hydrodynamic interaction of ice floes with underwater hull, including the scale effect. Conclusions. The methods that take into account the water resistance effect on predictions of ship ice resistance based on towing test data obtained in ice basins are reviewed and analyzed. An improved method to include the water resistance effect in a more correct way is suggested. For better comparison of test results in ice basin it is required to introduce a common method of including the water resistance effect using the method suggested in this work.

Experimental Investigation of Wave Loads Based on Trimaran Self-Propulsion Model

2016 ◽  
Author(s):  
Wei Xiaobo ◽  
Huilong Ren ◽  
Yanlong Sun ◽  
Di Wang ◽  
Zhen Yu Wang
Keyword(s):  
Model Test ◽  
High Speed ◽  
High Performance ◽  
Similarity Theory ◽  
Scale Model ◽  
Comprehensive Model ◽  
Wave Loads ◽  
Test Results ◽  
Regular Waves ◽  
Test Study

Trimaran, as a high performance ship, its special ship form is different from regular monohull ship. The particular characteristics of longitudinal and transverse wave loads are concerned greatly by ship structure designers. Theoretical methods for forecasting the wave loads of trimaran are under developing. And the relative comprehensive model test study of trimaran’s wave loads is rare in the publication. In this paper, the trimaran model test had been carried out in the tank. According to similarity theory and simulation of stiffness, a scale model of trimaran with measurement system had been manufactured. Then the segmented model had navigated in regular waves of different sea conditions. Through analysis of the experimental data, the wave loads characteristics of this trimaran are presented. A comparison of test results and theoretical values is also made to show the similarities and differences. This study can provide some useful information for further design of high-speed trimaran in the point of wave loads, which maybe a reference for research of trimaran.

Test Study on Dewatering Effect of Sewage Sludge by Vacuum Method

2012 ◽  
Vol 446-449 ◽  
pp. 1670-1673
Author(s):  
Yu Feng Gao ◽  
Guo Qing Du ◽  
Yuan Zhou ◽  
Shu Mao Wang
Keyword(s):  
Sewage Sludge ◽  
Model Test ◽  
Solid Content ◽  
Test Results ◽  
Test Study ◽  
Vacuum Method ◽  
Filter Clogging ◽  
Solid Liquid ◽  
Vacuum Dewatering

The aeration-vacuum dewatering method is a new kind of solid-liquid separate technique. The filter clogging problem in the routine vacuum dewatering procedure of sludge can be solved by the method. This method is used to dewater the sewage sludge in this paper. Through the dewatering model test of the sewage sludge with this method, the change law of the solid content and the volume of the sewage sludge are studied. The dewatering effect of sewage sludge is got further more. The test results indicate that there is a great promotion for improving the solid content and reducing the volume by using the aeration-vacuum method.

scholarly journals An Experimental Evaluation of Vortex-Induced Vibration of a Riser Bundle With Gaps

2009 ◽  
Author(s):  
J. Kim Vandiver ◽  
Yongming Cheng ◽  
Vivek Jaiswal ◽  
Aditi Sheshadri ◽  
Alan Yu
Keyword(s):  
Free Vibration ◽  
Model Test ◽  
Flow Direction ◽  
Angle Of Attack ◽  
Cross Flow ◽  
Test Results ◽  
Vortex Induced Vibration ◽  
Towing Tank ◽  
Helical Strakes ◽  
Rigid Model

VIV model test results are presented for a bundle of three parallel pipes all lying in the same plane, similar to a riser with large kill and choke lines. The rigid model was attached to a spring-mounted frame in the MIT towing tank. The horizontal model was towed in the tank and allowed to respond in free vibration to vortex-induced vibration in the cross-flow direction. The angle of attack of the model was varied from 0 to 90 degrees. The model was tested with and without helical strakes. Without strakes the model exhibited significant vibration at 0 and 90 degrees angle of attack. Strakes suppressed VIV at all angles of attack.

Research on the Hydrodynamic Performance of Zero Speed Fin Stabilizer

2021 ◽  
Author(s):  
Yuefeng Wei ◽  
Yi Yang
Keyword(s):  
Numerical Calculation ◽  
Angular Velocity ◽  
Model Test ◽  
Lift Force ◽  
Hydrodynamic Performance ◽  
Test Results ◽  
Rolling Moment ◽  
Swing Angle ◽  
Fin Stabilizer ◽  
Good Agreement

Abstract Nowadays, zero speed fin stabilizer has been initially applied in ship. Whether zero speed fin stabilizer can generate enough lift moment to resist rolling moment or not, determines the anti-rolling effect of ship at zero speed. In the present paper, numerical model is proposed to calculate the lift force and moment of zero speed fin stabilizer. The results of numerical calculation are verified by model test results and the hydrodynamic performance of zero speed fin stabilizer are studied. The numerical results are in good agreement with the model test results. For different swing angular velocity of a zero speed fin stabilizer, the lift force and moment of zero speed fin stabilizer reach the maximum at the same swing angle. For the same swing angle of a zero speed fin stabilizer, the lift force and moment of zero speed fin stabilizer are proportional to the square of angular velocity.

A Model Test Study on the Effect of the Stern Interceptor for the Reduction of the Resistance and Trim Angle for Wave-piercing Hulls

2015 ◽  
Vol 52 (6) ◽  
pp. 485-493 ◽  
Author(s):  
Dae Hyuk Kim ◽  
Inn-Duk Seo ◽  
Key-Pyo Rhee ◽  
Nakwan Kim ◽  
Jin-Hyung Ahn
Keyword(s):  
Model Test ◽  
Test Study

Inclined Loading Capacity of Embedded Suction Anchors in Clay

2009 ◽  
Author(s):  
Y. S. Kim ◽  
K. O. Kim ◽  
Y. Cho ◽  
S. Bang ◽  
K. D. Jones
Keyword(s):  
Analytical Solution ◽  
Model Test ◽  
Inclination Angle ◽  
Load Application ◽  
Centrifuge Model Test ◽  
Loading Capacity ◽  
Test Results ◽  
Pullout Capacity ◽  
Centrifuge Model ◽  
Inclined Loading

An analytical solution has been developed to estimate the inclined pullout capacity of an embedded suction anchor in clay seafloor. Validation has been made through comparisons with a limited number of centrifuge model test results. Results indicate that the inclined pullout capacity of an embedded suction anchor in clay decreases as the load inclination angle to the horizontal increases. As the point of the load application moves downward, the inclined pullout capacity increases, reaches its peak, and then starts to decrease.

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