• 대한조선학회논문집
• /
• 제57권1호
• /
• pp.15-22
• /
• 2020

Understanding the strength characteristics of model ice is an important issue for model testing in an ice model basin to estimate the ship performance in ice. In particular, the mechanical properties of the model ice including elastic modulus, flexural strength and compressive strength are key consideration factors. In order to understand the characteristics of the model ice during warm-up phase at KRISO's ice model basin, the strength properties are tested in this study. The infinite plate-bending method, in-situ cantilever beam test and ex-situ uniaxial compressive test are conducted to determine the strength properties of model ice. The strength characteristics of the model ice are then analyzed in terms of the warm-up phase and seasonality. These results could be valuable to quality control of the model ice characteristics in KRISO's ice model basin and to better understand the variations in strength properties during the ice model tests.

• 대한조선학회논문집
• /
• 제59권2호
• /
• pp.89-95
• /
• 2022

The stability of the existing ships has been evaluated through numerical calculations in the steady-state, but recently the IMO proposed a new stability assessment criteria that the stability is evaluated in the state in which environmental loads from such as waves and wind act like the loads under actual ship operating conditions. In this study, IMO 2nd generation stability assessment method and procedure were summarized for the dead ship condition, and Direct Stability Assessment (DSA) was performed on 13K chemical tanker through basin model test. The model test is performed in the ocean engineering basin to implement wave and wind loads, and environmental conditions for waves were set height and period of the incident wave, considering the regular wave and wind generation range reproducible in the ocean engineering basin. In addition, to consider the effect of wind speed, the Beaufort Scale for wind speed was applied in the model test.

• 한국해양공학회지
• /
• 제22권3호
• /
• pp.64-70
• /
• 2008

A full-scale field experiment is an important part in the design of ships and offshore structures. Full-scale tests in the ice-covered sea, however, are usually very expensive and difficult tasks. Model tests in a refrigerated ice tank may substitute this difficulty of full-scale field tests. One of the major tasks to perform proper model tests in an ice towing tank is to select a realistic material for model ice which shows correct similitude with natural sea ice. This study focuses on the testing material properties and the selection of model ice material which will be used in an ice model basin. The first Korean ice model basin will be constructed at the Maritime & Ocean Engineering Research Institute (MOERI) in 2009. With an application to the MOERI ice model basin, in this study the material properties of EG/AD/S model ice of IOT (Institute for Ocean Technology) Canada, were tested. Through comprehensive bending tests, the elastic modulus and the flexural strength of EG/AD/S model ice were evaluated and the results were compared with published test results from Canada. Instead of using an ice model basin, a cold room facility was used for making a model ice specimen. Since the cold room adopts a different freezing procedure to make model ice, the strength of the model ice specimen differs from the published test results. The reason for this difference is discussed and the future development for a making model ice is recommended.

• 한국수자원학회:학술대회논문집
• /
• 한국수자원학회 2023년도 학술발표회
• /
• pp.27-27
• /
• 2023

To analyze the evolution of water resources in Qiandao Lake Basin under the condition of climate change, a WEP-L distributed hydrological model was established to simulate the water cycle process in the basin during 1960-2020. The Mann-Kendall non-parametric test method and Hurst index method were used to analyze the inter-annual variation and annual distribution characteristics of the total water resources in the basin. The multi-scale temporal and spatial distribution and evolution trend of water resources in Qiandao Lake Basin were evaluated. The results show that: (1) The WEP-L model has good simulation results in the Qiandao Lake basin, and the Nash coefficient rate is above 0.83 in the periodic period and above 0.85 in the verification period. (2) The water yield coefficient of the whole basin ranges from 0.436 to 0.630. The annual average total water resource is 12.25 billion m³, equivalent to 1176.4mm of water depth. The annual distribution process shows a unimodal structure, and the water depth of each sub-basin ranges from 742 mm to 1266 mm, and the spatial distribution is higher in the west and lower in the east. (3) The annual water resources series in the basin showed an insignificant upward trend, and the Hurst index was 0.86, indicating a continuous upward trend. From the perspective of monthly water resources, January and February increased significantly, the other months were not significant changes.

• Ocean Systems Engineering
• /
• 제8권4호
• /
• pp.427-439
• /
• 2018

Floating Production Storage and Offloading (FPSO) units have the advantages of their ability to provide storage and offloading capabilities which are not available in other types of floating production systems. In addition, FPSOs also provide a large deck area and substantial topsides payload capacity. They are in use in a variety of water depths and environments around the world. It is a good solution for offshore oil and gas development in fields where there is lack of an export pipeline system to shore. However due to their inherently high motions in waves, they are limited in the types of risers they can host. The Low Motion FPSO (LM-FPSO) is a novel design that is developed to maintain the advantages of the conventional FPSOs while offering significantly lower motion responses. The LM-FPSO design generally consists of a box-shape hull with large storage capacity, a free-hanging solid ballast tank (SBT) located certain distance below the hull keel, a few groups of tendons arranged to connect the SBT to the hull, a mooring system for station keeping, and a riser system. The addition of SBT to the floater results in a significant increase in heave, roll and pitch natural periods, mainly through the mass and added mass of the SBT, which significantly reduces motions in the wave frequency range. Model tests were performed at the Korea Research Institute of Ships & Ocean Engineering (KRISO) in the fall of 2016. An analytical model of the basin model (MOM) was created in Orcaflex and calibrated against the basin-model. Good agreement is achieved between global performance results from MOM's predictions and basin model measurements. The model test measurements have further verified the superior motion response of LM-FPSO. In this paper, numerical results are presented to demonstrate the comparison and correlation of the MOM results with model test measurements. The verification of the superior motion response through model test measurements is also presented in this paper.

• International Journal of Naval Architecture and Ocean Engineering
• /
• 제7권3호
• /
• pp.466-477
• /
• 2015

In this study, a numerical prediction method on manoeuvrability of Wind Turbine Installation Vessel (WTIV) is presented. Planar Motion Mechanism (PMM) captive test for the bare hull of WTIV is carried out in the model basin and compared with the numerical results using RANS simulation based on Open-source Field Operation And Manipulation (OpenFOAM) calculation to validate the developed method. The manoeuvrability of WTIV with skeg and/or without skeg is investigated using the numerical approach along with the captive model test. In the numerical calculations, the dynamic stability index which indicates the course keeping ability is evaluated and compared for three different hull configurations i.e. bare hull and other two hulls with center skeg and twin skeg. This paper proves that the numerical approach using RANS simulation can be readily applied to estimate the manoeuvrability of WTIV at the initial design stage.

• 한국기계기술학회지
• /
• 제13권4호
• /
• pp.109-115
• /
• 2011

The ice tank is important facility to check the performance of the ship and offshore in ice condition before the construction. MOERI(Maritime & Ocean Engineering Research Institute) constructed ice model basin on the end of 2010. The ice technology to know the phenomena of ice near the ship and to estimate power of the ship in model scale is the main characteristic of the ice model basin. To achieve this goal in one ice sheet, making of test plan and feasibility check of test possibility have to review in the beginning stage of the every test. This paper describes the number of maximum resistance and self propulsion test in a sheet of level ice and proposes the methodology to optimize pack ice, rubble ice, brash ice and ice ridge test in MOERI ice tank. The feasibility of free running test to know maneuvering performance in ice field and some specific idea to measuring ice thickness and ice ridge shape was proposed.

• Journal of Advanced Marine Engineering and Technology
• /
• 제36권5호
• /
• pp.627-634
• /
• 2012

본 연구는 개발된 인플래터블 카약의 유체역학적인 성능평가를 위한 수조시험 및 그 결과에 대한 내용을 포함하고 있다. 개발된 인플래터블 카약과 해외제품에 대한 경사시험, 선회시험은 해양공학수조에서 시제품에 대한 시험이 수행되었고 저항시험은 회류수조에서 축소된 모형선을 이용한 시험이 수행되어졌다. 다음과 같은 성능평가 방법을 이용하여 개발된 카약과 해외제품에 대한 각각의 장 단점이 비교되어졌다.

• 물과 미래
• /
• 제22권1호
• /
• pp.109-116
• /
• 1989

본 연구는 SSARR 모형의 이론과 구조를 설명하고 보청천 유역의 자료를 사용, 모형의 매개변수를 추정하여 소유역에의 적용가능성을 파악하고자 하였다. 모형에 사용된 자료기간은 1982∼1988년까지이며 사용된 자료는 금강수계의 하나인 보청천 유역이다. 모형의 매개변수의 산정과 사용된 매개변수의 특성을 파악하고자 민감도 분석을 실시 하였다.

• 한국해양공학회:학술대회논문집
• /
• 한국해양공학회 2001년도 추계학술대회 논문집
• /
• pp.97-102
• /
• 2001

This paper describes an investigation how to carry out model tests of deepwater moorings exceeding the basin depth range. A hybrid mooring model, a combination of mooring lines scaled model and a couple of linear springs, is taken into account as an equivalent substitute of a full depth mooring system. Such an idea is applied to the model test of an OTEC mooring system to be installed in 1000m deep ocean. A 1/25 scaled model test of surface vessel and the upper part of mooring system is performed at ocean engineering basin. Possibility and limitation of the hybrid mooring modeling is discussed.