Study on Resistance Performance of Ice-Breaking Tanker According to Ship’s Length

2018 ◽  
Author(s):  
Seong-Rak Cho ◽  
Jinho Jang ◽  
Cheol-Hee Kim ◽  
Eun-Jin Oh ◽  
Kuk-Jin Kang ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Open Water ◽  
Model Tests ◽  
Ice Friction ◽  
Resistance Performance ◽  
Ice Model ◽  
Resistance Component

In this paper, ice model tests with different lengths of parallel middle-body were conducted to estimate accurate resistance performance of ice-breaking merchant vessels. Totally, three model ships were manufactured: The standard vessel is 90,000 DWT tanker to transport oil in the ARC7 condition, and two vessels have only different lengths of parallel middle-ship compared to the standard vessel. Ice breaking, ice friction, ice buoyancy, and open-water resistances were classified and measured in experiments, and each resistance component according to change of ship’s length is analyzed. In addition, the resistance formula of ice-breaking tanker is developed by a regression analysis.

scholarly journals Model-Scale/Full-Scale Correlation in Open Water and Ice for Canadian Coast Guard “R-Class” Icebreakers

2001 ◽  
Vol 45 (04) ◽  
pp. 249-261
Author(s):  
Don Spencer ◽  
Stephen J. Jones
Keyword(s):  
Friction Coefficient ◽  
Structural Damage ◽  
National Research Council ◽  
Open Water ◽  
Model Tests ◽  
Full Scale ◽  
Coast Guard ◽  
Model Scale ◽  
Ice Friction ◽  
Good Agreement

CCGS Pierre Radisson, one of the R-Class icebreakers Model-scale data from the National Research Council of Canada, Institute for Marine Dynamics' water and ice towing tanks for the Canadian Coast Guard's R-Class icebreaker are compared with previous model tests and, more importantly, with three sets of full-scale ice trials data collected in 1978, 1979 and 1991. In open water, good agreement between model-and full-scale was found for bollard tests, and for self-propulsion tests provided a roughness allowance of 0.0008 was used. In ice, good correlation was found with the 1978 tests when the ship was new and there was little snow cover, using a model hull/ice friction coefficient of 0.05. Good agreement with the later tests, 1979 and 1991, was also obtained with somewhat higher model/ice friction coefficients of 0.055 and 0.065. This is attributed to a deteriorating, and hence rougher, full-scale ship hull surface. The model tests showed that a change in friction coefficient from 0.03 to 0.09 causes a doubling of the delivered power. For the full-scale ship, it is suggested that relatively inexpensive localized hull maintenance in the shoulder area, where ice jamming occurs and hence hull/ice friction is important, could improve performance and reduce the chance of structural damage.

scholarly journals Observations and Simulations of Meteorological Conditions over Arctic Thick Sea Ice in Late Winter during the Transarktika 2019 Expedition

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 174
Author(s):  
Günther Heinemann ◽  
Sascha Willmes ◽  
Lukas Schefczyk ◽  
Alexander Makshtas ◽  
Vasilii Kustov ◽  
...  
Keyword(s):  
Sea Ice ◽  
Climate Models ◽  
Climate Model ◽  
Regional Climate ◽  
Open Water ◽  
The Arctic ◽  
Late Winter ◽  
Good Representation ◽  
Hourly Temperature ◽  
Ice Model

The parameterization of ocean/sea-ice/atmosphere interaction processes is a challenge for regional climate models (RCMs) of the Arctic, particularly for wintertime conditions, when small fractions of thin ice or open water cause strong modifications of the boundary layer. Thus, the treatment of sea ice and sub-grid flux parameterizations in RCMs is of crucial importance. However, verification data sets over sea ice for wintertime conditions are rare. In the present paper, data of the ship-based experiment Transarktika 2019 during the end of the Arctic winter for thick one-year ice conditions are presented. The data are used for the verification of the regional climate model COSMO-CLM (CCLM). In addition, Moderate Resolution Imaging Spectroradiometer (MODIS) data are used for the comparison of ice surface temperature (IST) simulations of the CCLM sea ice model. CCLM is used in a forecast mode (nested in ERA5) for the Norwegian and Barents Seas with 5 km resolution and is run with different configurations of the sea ice model and sub-grid flux parameterizations. The use of a new set of parameterizations yields improved results for the comparisons with in-situ data. Comparisons with MODIS IST allow for a verification over large areas and show also a good performance of CCLM. The comparison with twice-daily radiosonde ascents during Transarktika 2019, hourly microwave water vapor measurements of first 5 km in the atmosphere and hourly temperature profiler data show a very good representation of the temperature, humidity and wind structure of the whole troposphere for CCLM.

Model Tests in Brash Ice Channels

2005 ◽  
Author(s):  
Jens-Holger Hellmann ◽  
Karl-Heinz Rupp ◽  
Walter L. Kuehnlein
Keyword(s):  
Perforated Plate ◽  
Ice Sheet ◽  
Open Water ◽  
Model Tests ◽  
Ice Thickness ◽  
Special Device ◽  
Level Ice ◽  
Set Up ◽  
Parental Level ◽  
Oil Tankers

According to the present Finnish-Swedish Ice Class Rules (FSICR) the formulas for the required main engine power for tankers led to much bigger main engines than it is needed for the demanded open water speed. Therefore model tests may be performed in order to verify the vessel’s capability to sail with less required power in brash ice channels compared to the calculations. Several model test runs have been performed in order to study the performance of crude oil tankers sailing in brash ice. The tests were performed as towed propulsion tests and the brash ice channel was prepared according to the guidelines set up by the Finnish Maritime Administration (FMA). The channel width was 2 times the beam of the tanker. The model tests were carried out at a speed of 5 knots. For the tests a parental level ice sheet of adequate thickness is prepared according to HSVA’s standard model ice preparation procedure. After a predefined level ice thickness has been reached, the air temperature in the ice tank will be raised. An ice channel with straight edges will be cut into the ice sheet by means of two ice knives. The ice stripe between the two cuts will be manually broken up into relatively small ice pieces using a special ice chisel and if required the brash ice material will be compacted. Typically the brash ice thickness will be measured prior the tests at 9 positions across the channel and every two meter over the entire length of the brash ice channel with a special device, which consists of a measuring rule with a perforated plate mounted under a right angle at the lower end of the rule. As a result of the tests it could be demonstrated that tankers with a capacity of more than 50 000 tons require 50% and even less power compared to calculations using the present FSICR formulas.

Resistance Tests of an Articulated Pusher Barge System in Deep and Shallow Water

2021 ◽  
Author(s):  
Li Zhang ◽  
Lei Xing ◽  
Mingyu Dong ◽  
Weimin Chen
Keyword(s):  
Shallow Water ◽  
Water Depth ◽  
Deep Water ◽  
Water Resistance ◽  
Model Tests ◽  
System 2 ◽  
Changing Trend ◽  
The Difference ◽  
Transport Vessel ◽  
Resistance Performance

Abstract Articulated pusher barge vessel is a short-distance transport vessel with good economic performance and practicability, which is widely used in the Yangtze River of China. In this present work, the resistance performance of articulated pusher barge vessel in deep water and shallow water was studied by model tests in the towing tank and basin of Shanghai Ship and Shipping Research Institute. During the experimental investigation, the articulated pusher barge vessel was divided into three parts: the pusher, the barge and the articulated pusher barge system. Firstly, the deep water resistance performance of the articulated pusher barge system, barge and the pusher at design draught T was studied, then the water depth h was adjusted, and the shallow water resistance at h/T = 2.0, 1.5 and 1.2 was tested and studied respectively, and the difference between deep water resistance and shallow water resistance at design draught were compared. The results of model tests and analysis show that: 1) in the study of deep water resistance, the total resistance of the barge was larger than that of the articulated pusher barge system. 2) for the barge, the shallow water resistance increases about 0.4–0.7 times at h/T = 2.0, 0.5–1.1 times at h/T = 1.5, and 0.7–2.3 times at h/T = 1.2. 3) for the pusher, the shallow water resistance increases about 1.0–0.4 times at h/T = 2.7, 1.2–0.9 times at h/T = 2.0, and 1.7–2.4 times at h/T = 1.6. 4) for the articulated pusher barge system, the shallow water resistance increases about 0.2–0.3 times at h/T = 2.0, 0.5–1.3 times at h/T = 1.5, and 1.0–3.5 times at h/T = 1.2. Furthermore, the water depth Froude number Frh in shallow water was compared with the changing trend of resistance in shallow water.

Ice Resistance Performance Analysis of Double Acting Tanker in Astern Condition

2014 ◽  
Vol 69 (7) ◽  
Author(s):  
Efi Afrizal ◽  
Jaswar Koto
Keyword(s):  
Performance Analysis ◽  
Open Water ◽  
Hull Form ◽  
Propeller Design ◽  
Objective Parameter ◽  
Form Design ◽  
Hull Form Design ◽  
Design Analyses ◽  
Resistance Performance ◽  
Ice Resistance

An optimum procedure of hull form design for ice ship going “Double Acting Tanker” is introduced. The procedure orderly consist of hull form design, analyses of performance of a ship in open water and ice condition, maneuverability performance, ice loading effect on propeller and torsional shaft, and economical and environmental societies. In the present study, only two topics are mainly discussed, which are hull form design and then continued with performance analysis in ice condition and open water. For the hull form design the objective parameter are considered as follows; stem and the stern angles, upper and lower fore bulbous angles, entrance angles, and spreading angles. All those angles are investigated for both full loaded and ballast condition in ahead and astern. Special concern is needed for stern part due to existing propeller effect on ice breaking performance. The hull form is firstly investigated without installation of propeller to avoid the effect of pressure from propeller and then continued by installation of propeller to find the optimum propeller design and propeller immersion. Research in ice condition is compromised with open water. The optimum hull form, propeller design and propeller immersion is when the hull form gives better performance for both open water and ice condition. The selected hull form then is compared with existing DAT tanker “Tempera”.

Oil Skimming Efficiency of the SOS: Scaling From GeoSim Model Tests to Full Scale Prototype Operations

2012 ◽  
Author(s):  
Günther F. Clauss ◽  
Sascha Kosleck ◽  
Florian Sprenger ◽  
Laura Grüter
Keyword(s):  
Flow Pattern ◽  
Oil Recovery ◽  
Open Water ◽  
Model Tests ◽  
Full Scale ◽  
Polluted Water ◽  
Water Separation ◽  
Weathering Processes ◽  
River Elbe ◽  
Hydrodynamic Effects

The severe ecological and economical aftermath of the 2010 ‘Deepwater Horizon’ catastrophe in the Gulf of Mexico clearly shows the insufficiency of current oil recovery systems which cannot operate in wave heights above 1.5m. To prevent emulsification and weathering processes, it is necessary to skim the oil film off the sea surface shortly after the accident. The autonomous SOS (Sea State-independent Oil Skimming System) developed within the framework of the research project SOS3 features high transit velocities, the capability of operating in rough seas and a massive intake of oil polluted water — and is therefore a unique technology. The oil water separation process of the SOS is purely based on hydrodynamic principles involving vortex evolution and a special flow pattern inside the internal moon pool. These requirements for efficient oil skimming operations depend on various hydrodynamic effects that would imply model testing in compliance with Froude’s and Reynolds’ law simultaneously — a physically impossible condition. Therefore GeoSim model tests with the SOS at model scales of 1:16, 1:25 and 1:36 are conducted with discrete particles of the correct density substituting the oil phase. The tendencies in flow pattern evolution and oil skimming efficiency are compared and extrapolated to full scale. Results from open water tests with the prototype of the SOS in the mouth of river Elbe serve for validation of the extrapolated results.

Double Acting Tanker: Experiences from Model Tests and Sea Trials

2005 ◽  
Vol 219 (3) ◽  
pp. 109-119 ◽  
Author(s):  
P Trägärdh ◽  
P Lindell ◽  
N Sasaki
Keyword(s):  
Model Test ◽  
Oil And Gas ◽  
Single Point ◽  
Open Water ◽  
Model Tests ◽  
Water Model ◽  
Research Centre ◽  
Sea Trial ◽  
Cavitation Performance ◽  
Ice Conditions

The acronym DAT stands for double acting tanker, a concept where the ship is designed to run astern in heavy ice conditions while remaining hydrodynamically efficient for ahead propulsion in open water conditions. Two large aframax DATs - 106.000 dwt (deadweight tons) each - have been delivered by Sumitomo Heavy Industries to Fortum Oil and Gas OY. They are the first crude carriers built according to the DAT principle and also the first using pod propulsion from the beginning (Fig. 1). They will also be the world's largest crude carriers with ice class 1A super and are primarily intended for year-round transportation of North Sea crude to Fortum's refineries in the Gulf of Finland. The ships were appointed ‘ship of the year’ in Japan in 2003. SSPA was contracted by Sumitomo Heavy Industries to perform model tests. A comprehensive open water model test programme was used to investigate aspects of resistance and propulsion, manoeuvring, and cavitation performance. As the ship is designed to operate both in ahead and astern conditions for prolonged periods of time, most tests were performed both ahead and astern. Also, a simulation study of dynamic positioning at buoy or floating production, storage offshore (FPSO) loading was made by SSPA. Comprehensive tests of the ship's performance in ice were performed in the ice tank at MARC (Masa-Yards Artic Research Centre). The eight-month model testing and development campaign resulted in a ship with excellent propulsion and manoeuvring performance, especially with regard to the high ice class. Sea trials carried out with ship in August 2002 confirmed the results of the model test. Interesting experiences of the model test campaign and comparison between model test and sea trial results are presented, as well as some examples of single-point mooring simulations.

scholarly journals Experimental model tests to improve a tanker resistance performance

2021 ◽  
Vol 44 ◽  
pp. 11-14
Author(s):  
Dan Obreja
Keyword(s):  
Experimental Model ◽  
Model Tests ◽  
Experimental Techniques ◽  
Naval Architecture ◽  
Towing Tank ◽  
Ship Resistance ◽  
Design Speed ◽  
Bulbous Bow ◽  
Resistance Performance ◽  
Ship Speed

The ship resistance is one of the most important hydrodynamics performances, being related to the contractual ship speed. The experimental model tests can be used to measure and improve the resistance performance. In this paper, the possibility of using the experimental techniques in order to improve a tanker model resistance is demonstrated, based on a bulbous bow modelling solution. In this context, the results obtained in the Towing Tank of the Naval Architecture Faculty of “Dunarea de Jos” University of Galati, related to a tanker model resistance with and without bulbous bow are presented. The bulbous bow form was realised based on the hydrodynamics principles adapted to the bow forms of the tanker. In the case of the bulbous bow solution, a significant reduction of over 8% of the tanker model resistance was obtained, in the design speed domain.

Design and Performance Analysis of Vane Wheel

2015 ◽  
Author(s):  
Woo-Chan Seok ◽  
Hyoungsuk Lee ◽  
Tobias Zorn ◽  
Vladimir Shigunov
Keyword(s):  
Open Water ◽  
Power Reduction ◽  
Model Tests ◽  
Propulsive Efficiency ◽  
Towing Tank ◽  
Momentum Theory ◽  
Computational Fluid Dynamics Cfd ◽  
Overall Performance ◽  
And Performance ◽  
Blade Element

For the analysis, a vane wheel was considered consisting of two portions, namely, a turbine portion and a propeller portion. The turbine portion was designed using Blade Element Momentum Theory (BEMT); the propeller portion, Computational Fluid Dynamics (CFD) under open-water conditions. Model tests were conducted at Hyundai Maritime Research Institute (HMRI) in their towing tank, using a Contra Rotating Propeller (CRP) dynamometer. Model tests as well as full-scale CFD calculations were performed to predict overall performance. The CFD calculations showed better performance compared to the model tests. In general, the analyzed vane wheel improved the propulsive efficiency via power reduction compared to the case without a vane wheel.

Numerical Prediction of Propeller Characteristics

1973 ◽  
Vol 17 (01) ◽  
pp. 12-18
Author(s):  
Damon E. Cummings
Keyword(s):  
Open Water ◽  
Model Tests ◽  
Numerical Prediction ◽  
Water Model ◽  
Variable Pitch ◽  
Cavitation Inception ◽  
Fraction Distribution ◽  
Thrust And Torque ◽  
Ship Speed

A procedure is described for predicting the performance of a propeller numerically to within the accuracy of tunnel and open-water model tests. Given the geometry of the propeller, ship speed, wake fraction distribution and rpm, the thrust and torque characteristics are calculated. The procedure gives good results not only for "normal" propellers but also for such abnormal cases as a variable-pitch propeller operating at off-design pitches. The possibility exists of extension of the method for calculation of spindle torques, stresses, and cavitation inception.

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