Study on the Ship Ice Resistance Estimation Using Empirical Formulas

2014 ◽  
Author(s):  
Kyung Duk Park ◽  
Hyun Soo Kim
Keyword(s):  
Model Test ◽  
High Reliability ◽  
Main Idea ◽  
Estimation Technique ◽  
Empirical Formulas ◽  
Level Ice ◽  
Arctic Ice ◽  
Ice Model Test ◽  
Ice Resistance ◽  
Ice Model

The ice resistance estimation technique for icebreaking ships has been studied intensively over recent years to meet the need of arctic vessel design. Before testing in the ice model basin, the estimation of ship ice resistance with high reliability is very important to decide the delivered power necessary for level ice operation. The main idea of this study came from several empirical formulas by B.P. Ionov[1], E. Enkvist[2] and J.A. Shimanskii[3], in which ice resistance components such as icebreaking, buoyancy and clearing resistances were represented by the integral equations along the DLWL (Design Load Water Line). However, this study proposes modified methods considering the DLWL shape as well as the hull shape under the DLWL. In the proposed methodology, the DLWL shape for icebreaking resistance and the hull shape under the DLWL for buoyancy and clearing resistances are included in the calculation. Especially when calculating clearing resistance, the flow pattern of ice particles under the DLWL of ship is assumed to be in accordance with the ice flow observed from ice model testing. This paper also deals with application examples for a ship design and its ice model test results at the Aker arctic ice model basin. From the comparison of results from the model test and the estimation, the reliability of this estimation technique is discussed.

Ice Resistance Model Test Technology for 110K Tanker Adopting FSICR Ice Class IA

2013 ◽  
Vol 779-780 ◽  
pp. 1117-1123
Author(s):  
Jia Ning Zhang ◽  
Yu Chen Shang ◽  
Lei Zhang
Keyword(s):  
Output Power ◽  
Model Test ◽  
Technical Requirements ◽  
Ship Model Test ◽  
Ice Model Test ◽  
Ice Navigation ◽  
Primary Measure ◽  
Oil Tanker ◽  
Ice Resistance ◽  
Ice Model

Ship model test in ice towing tank is one of the key technologies for the design of ice-strengthened ship, and is the primary measure of determining the ship required minimum engine output power in ice navigation and checking whether satisfies the requirements of ice class rules. Researched the relevant requirements of 1A ice-strengthened ship based on the Finnish-Swedish ice class rules (FSICR), which is minimum engine output power according to the forward form of hull line and according to standard formulas. Studied the technical requirements of ice model test. Determined the minimum engine output power for 110k oil tanker with ice class 1A based on ice model test.

Ice Model Testing of Structures With a Downward Breaking Cone at the Waterline JIP: Presentation, Set-Up and Objectives

2011 ◽  
Author(s):  
Per Kristian Bruun ◽  
Sveinung Lo̸set ◽  
Arne Gu¨rtner ◽  
Guido Kuiper ◽  
Ted Kokkinis ◽  
...  
Keyword(s):  
First Year ◽  
Test Set ◽  
Ice Load ◽  
Fixed Model ◽  
Ice Conditions ◽  
Level Ice ◽  
Ice Model Test ◽  
Set Up ◽  
Ice Failure ◽  
Ice Model

Two large ice model test campaigns were performed in the period 2007–2010 as a part of a Joint Industry Project. The objectives of the project were to investigate different floater geometries and ice model test set-ups (model fixed to a carriage and pushed through the ice vs. ice pushed towards a floating model moored to the basin bottom) and their influence on the ice failure mode and structure responses in the various tested ice conditions. This paper presents the objectives and motivations for the project, the models tested, the target test set-up for the various tested configurations and the test matrix. Initial results from a fixed model tested in three first-year ice ridges with similar target ice properties are also presented and compared. Fixed models of both deep and shallow water platforms were tested in various ice conditions. All models except one had a downward breaking cone at the waterline. The influences of the waterline diameter, the angle of the downward breaking cone and the vertical cone height on the ice failure mode and the resulting ice load were investigated. Tests were conducted in level ice with a thickness ranging from 2 to 3 m and variable ice drift speeds ranging from 0.1 to 1.0 m/s in full scale values. The models were subjected to tests in managed level ice with varying speeds, ice concentrations and ice floe sizes. Fixed structures were also subjected to testing in typical first-year design ice ridge conditions with ridges of different depths and widths, as well as one multi-year ice ridge. One fixed model was also utilised for testing of the repeatability of scaled ice model testing. Moored models with the same waterline geometry as the fixed models were also tested. The moored models were tested in ice conditions similar to those of the fixed models with the objective of comparing their influences on the ice load due to structural responses.

The Resistance of Ice Breaking Ships Based on Model Tests

2015 ◽  
Author(s):  
Seong-Rak Cho ◽  
Kuk-Jin Kang ◽  
Sungsu Lee
Keyword(s):  
Model Tests ◽  
Design Stage ◽  
Preliminary Design ◽  
Factors Associated ◽  
Preliminary Design Stage ◽  
Level Ice ◽  
Resistance Prediction ◽  
Ice Resistance ◽  
Priority Factor ◽  
Ice Model

The two most important tasks of ice breaking ships are first to secure a sailing route by breaking the thick sea ice and second to sail efficiently herself for purposes of exploration and transportation in the polar seas. The resistance of ice breaking ships is a priority factor at the preliminary design stage; not only must their sailing efficiency be satisfied, but the design of the propulsion system will be directly affected. Therefore, the performance of ice-breaking ships must be accurately calculated and evaluated through the use of model tests in an ice model basin before construction starts. In this paper, a new procedure is developed, based on model tests, to estimate a ship’s ice resistance during continuous icebreaking in level ice. Some of the factors associated with crushing failures are systematically considered in order to correctly estimate her ice-breaking resistance, while the effects of the hull geometry, as reflected in the length, breadth, and draft of ships, are considered in calculating buoyancy and clearing resistance. Multiple regression analysis is calculated with each ice resistance component. This study is intended to contribute to the improvement of the techniques for ice resistance prediction with ice breaking ships.

scholarly journals A Study on Improvement of Ice Model Test Procedure

2008 ◽  
Vol 45 (5) ◽  
pp. 562-568 ◽  
Author(s):  
Chun-Ju Lee ◽  
Seong-Rak Cho ◽  
Michael Lau ◽  
Jung-Yong Wang
Keyword(s):  
Model Test ◽  
Test Procedure ◽  
Ice Model Test ◽  
Ice Model

Experimental Investigation of Aspects Influencing the Level Ice Resistance of Ships With Non-Typical Icebreaking Bow Shapes

2021 ◽  
Author(s):  
Daniela Myland ◽  
Quentin Hisette ◽  
Emre Cilkaya ◽  
Yusuf Sefa Özhan
Keyword(s):  
Ice Sheets ◽  
Relevant Information ◽  
Interaction Process ◽  
Total Resistance ◽  
Ship Model ◽  
Load Cells ◽  
Level Ice ◽  
Ice Resistance ◽  
Different Thickness ◽  
Ice Model

Abstract For non-typical icebreaking ships the hull-ice interaction process in level ice comprises a combination of many different phenomena which is difficult to be described by existing straightforward approaches. In order to gain knowledge about the operability of such non-typical hull shapes in level ice, a study has been carried out to identify and evaluate the level ice resistance as well as its distribution along the hull of ships with non-typical icebreaking bow shapes with high stem and/or small waterline angles. For this purpose, one ship model has been manufactured and instrumented with several multi-axis load cells in the bow region of the waterline as well as with one large six-component load scale between the bow and the stern. Performing resistance model tests at several loading conditions in model ice sheets of different thickness and at multiple speed values allows obtaining relevant information to meet the goals of the study. The developed methodology and the analysis of the measured loads have been described in previous publications. As direct continuation, the present paper focuses on investigation of the ice floe characteristics and its linkage to the ice properties. Moreover, analysis results related to the crushing portion of the total resistance in ice, the friction between ice and ship model hull as well as the ship model motions during ice model testing are presented within the paper.

Validation of Pack Ice Resistance in Oblique Condition by the Comparison With Ice Model Test Results

2019 ◽  
Author(s):  
HyunSoo Kim ◽  
Erinc Ozden ◽  
Jae-bin Lee
Keyword(s):  
Model Test ◽  
Construction Projects ◽  
Arctic Region ◽  
Resource Development ◽  
Offshore Structures ◽  
The Arctic ◽  
Pack Ice ◽  
Ice Model Test ◽  
Ice Resistance ◽  
The Arctic Region

Abstract Countries around the world are increasingly interested in resource development in the Arctic due to global warming. Recently, Arctic coastal states (Russia, USA, Canada, etc.) are pursuing infrastructure construction projects for resource development in the Arctic region. Because the offshore structures in the Arctic are exposed to the sea ice, in order to ensure the safety of the structures, the calculation of the ice resistance is of paramount importance for offshore structures. In general, studies on the ice resistance have been carried out for the breaking and clearing performance of icebreakers. However, in the case of fpu (floating production unit) for resource development in the Arctic region, it is necessary to estimate the ice resistance in the oblique condition to ensure safety. Thus, despite estimation of the ice resistance in the oblique condition is significant, there has not been enough research until recently. In this paper, we suggest algorithms for estimating the ice resistance in the oblique condition. For the estimation process, an in-house code software program is used and an ice resistance estimation module is implemented for the oblique condition using empirical formula. This paper shows results of the ice resistance which was calculated in the oblique condition, and the change of the ice resistance is shown according to various oblique angles in pack ice. In addition, the results are compared to the model test result of a fpu in pack ice of 80% concentration.

Methodology to Investigate the Icebreaking Process of Ships With Non-Typical Icebreaking Bow Shapes

2020 ◽  
Author(s):  
Quentin Hisette ◽  
Daniela Myland
Keyword(s):  
Ice Sheets ◽  
Relevant Information ◽  
Model Tests ◽  
Interaction Process ◽  
Analysis Procedure ◽  
Load Cells ◽  
Level Ice ◽  
Ice Resistance ◽  
Different Thickness ◽  
Ice Model

Abstract For non-typical icebreaking ships the hull-ice interaction process in level ice comprises a combination of many different phenomena which is difficult to be described by existing straightforward approaches. In order to gain knowledge about the level ice resistance of such non-typical hull shapes for operation in ice, a methodology is developed and presented to identify and evaluate the level ice resistance as well as its distribution along the hull of ships with non-typical icebreaking bow shapes with high stem and/or small waterline angles. For this purpose, one ship model has been manufactured and instrumented with several multi-component load cells in the bow region of the waterline as well as with one large six-component load scale between the bow and the stern. Performing resistance model tests at several loading conditions, in model ice sheets of different thickness and at multiple speed values allows obtaining relevant information to meet the goals of the study. The paper focuses on the methodology used for the ice model tests and its analysis. Instrumentation of the model is fully described, together with an overview of the testing matrix and model test observations. Analysis procedure is described in details and applied on a representative test run of the campaign.

Ice Resistance Calculation Methods and Their Economic Impact on Ship Design

2015 ◽  
Author(s):  
Rüdiger U. Franz von Bock und Polach ◽  
Tõnis Tõns ◽  
Sandro Erceg
Keyword(s):  
Economic Impact ◽  
Model Tests ◽  
Empirical Formulas ◽  
Panel Methods ◽  
Ice Conditions ◽  
Resistance Prediction ◽  
Semi Empirical ◽  
Ice Resistance ◽  
Ice Model ◽  
Testing Design

A ship is an investment and built to create revenue. The decision whether the design of a ship is realized or not is therefore strongly affected by the natural obstacles of mission and route. The occurrence of ice along arctic routes is such an obstacle and affects significantly the resistance and the required propulsion power. Advanced simulation environments, such as panel methods or CFD do not exist yet for ice resistance calculations and hence semi-empirical formulations or model tests need to be employed to assess or validate a design. Ice model tests impose great expenses in terms of time and money, which often does not allow testing design variations. On the other hand, the results of semi-empirical formulas might be accompanied by significant uncertainties. The academic study presented in this paper is a transit simulation on the Northern Sea Route (NSR) for the ice-capable tanker MT Varzuga (formerly MT Uikku). The study evaluates the ice conditions along several NSR alterations and the ice resistance-related performance with available semi-empirical methods and ice model tests. Finally, the economic impact of the applied ice resistance prediction methods is evaluated and the differences are quantified.

Development of a Prediction Formula for Ship Resistance in Level Ice

2014 ◽  
Author(s):  
Seong-Rak Cho ◽  
Seong-Yeop Jeong ◽  
Sungsu Lee ◽  
Kook-Jin Kang
Keyword(s):  
Extreme Environments ◽  
Prediction Equation ◽  
Regression Analyses ◽  
Prediction Formula ◽  
Resistance Components ◽  
Northern Sea Route ◽  
Level Ice ◽  
Ice Resistance ◽  
Priority Factor ◽  
Ice Model

Icebreakers are mainly classified according to the breakable thickness of level ice, although they differ slightly according to each ship’s classification and by country. The breaking performance in level ice is a priority factor for icebreakers and is directly linked to ships’ safety and survival in extreme environments. In addition, some large cargo vessels with an icebreaking capability have recently been built, and various types of commercial icebreakers will appear when the Northern Sea Route is activated in the future. In this paper, previous studies on ice resistance are reviewed and analyzed by arranging the merits and demerits of each study. We developed a new prediction equation of ice resistance by analyzing the resistance components, such as the breaking, buoyancy, and clearing resistance, and using dimensional and regression analyses on ice model tests. This procedure could be applied to large merchant vessels and is intended to contribute to the prediction of icebreakers’ ice performance.

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