scholarly journals A Power Demand Analytical Model of Self-Propelled Vessels

2021 ◽  
Vol 9 (12) ◽  
pp. 1450
Author(s):  
Javier Zamora
Keyword(s):  
Practical Method ◽  
Power Demand ◽  
Total Resistance ◽  
Mathematical Equation ◽  
Model Data ◽  
Ocean Engineering ◽  
Data Variability ◽  
Korea Research Institute ◽  
Propeller Performance ◽  
Propulsion Power

The article herein presents a closed-form mathematical equation by which it is possible to estimate the propulsion power demand of ships as a function of the propeller parameters and total Resistance. The validation of the derived model is conducted by use of the Series 60 Model data and of the Korea Research Institute of Ships and Ocean Engineering (KRISO) Very Large Crude-oil Carrier 2 (KVLCC2) data. In all the cases tested, the derived model explained more than 99.9% of the data variability. Furthermore, the paper describes a practical method for quantifying changes in hull and propeller performance and provides an application example.

scholarly journals CFD Simulation for Estimating Efficiency of PBCF Installed on a 176K Bulk Carrier under Both POW and Self-Propulsion Conditions

Processes ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 1192
Author(s):  
Dong-Hyun Kim ◽  
Jong-Chun Park ◽  
Gyu-Mok Jeon ◽  
Myung-Soo Shin
Keyword(s):  
Cfd Simulation ◽  
Open Water ◽  
Navier Stokes ◽  
Water Efficiency ◽  
Ocean Engineering ◽  
Bulk Carrier ◽  
Incompressible Viscous Flow ◽  
Korea Research Institute ◽  
Torque Coefficient ◽  
Viscous Flow Field

In this paper, the efficiency of Propeller Boss Cap Fins (PBCF) installed at the bulk carrier was estimated under both Propeller Open Water (POW) and self-propulsion conditions. For this estimation, virtual model-basin tests (resistance, POW, and self-propulsion tests) were conducted through Computational Fluid Dynamics (CFDs) simulation. In the resistance test, the total resistance and the wake distribution according to ship speed were investigated. In the POW test, changes of thrust, torque coefficient, and open water efficiency on the propeller according to PBCF installation were investigated. Finally, the International Towing Tank Conference (ITTC) 1978 method was used to predict the effect of PBCF installation on self-propulsive coefficient and brake horsepower. For analyzing incompressible viscous flow field, the Reynolds-Averaged Navier–Stokes (RANS) equation with SST k-ω turbulence model was calculated using Star-CCM+ 11.06.010-R8. All simulation results were validated by comparing the results of model tests conducted at the Korea Research Institute of Ships and Ocean Engineering (KRISO). Consequently, for the self-propulsion test with the PBCF, a 1.5% reduction of brake horsepower was estimated in the simulation and a 0.5% reduction of the brake horsepower was estimated in the experiment.

Investigation of Environmental Effects of High Speed Boats

2020 ◽  
Author(s):  
Ahmet Dursun Alkan ◽  
Onur Usta ◽  
Alpay Acar ◽  
Elis Atasayan
Keyword(s):  
High Speed ◽  
Navier Stokes ◽  
Noise Prediction ◽  
Total Resistance ◽  
Test Results ◽  
Negative Effects ◽  
Towing Tank ◽  
Towing Tank Test ◽  
Tank Test ◽  
Propulsion Power

Luxury high-speed boats are increasingly being used for entertainment purposes. However, not only humans, but also animals are negatively affected by high-speed boats, and time is running out fast for people to do something about it. This study presents a review of current negative effects of high-speed boats to the environment. In this study, the flow around a benchmark planing Fridsma boat is simulated by CFD and resistance values for different non-dimensional Froude number (Fn) conditions are validated from the experimental results obtained from the literature. Using the same CFD methodology, a catamaran model in which the towing tank test results are available, is simulated for different Fn conditions and resistance values are predicted. In the CFD analysis, unsteady flow around the Fridsma hull model and catamaran model is simulated using overset meshing technique and turbulence is modeled by Reynolds Averaged Navier Stokes (RANS) with SST (Menter) k-omega turbulence model. Resistance values are compared with the experimental data and required propulsion powers are estimated for different Fn conditions. Then, total resistance of the catamaran for full-scale vessel is calculated using an extrapolation method and required propulsion power predictions are conducted. Noise prediction, corresponding to the required propulsion power are presented. In particular, the change of noise level and harmful gases released into the environment, when the speed of the vessel increases are examined and discussed. Consequently, it is believed that this study would lay an important foundation for the widespread investigation for the negative effects of the high-speed boats in the future.

The Study of Knowledge Based Geographic Information System

2015 ◽  
Vol 719-720 ◽  
pp. 691-695
Author(s):  
Hong Liang Shen ◽  
Chang Bao Yang ◽  
Guo Cheng Liu ◽  
Sheng Zhong Ma
Keyword(s):  
Information System ◽  
Geographic Information System ◽  
Knowledge Acquisition ◽  
System Design ◽  
Domain Knowledge ◽  
Practical Method ◽  
Geographic Information ◽  
Model Data ◽  
Knowledge Based ◽  
Reasoning Mechanism

The purpose of this paper is to develop a practical method which integrate the mighty function of GIS with KBS (Knowledge Based System) .It emphatically bring forward a prototype of KBGIS. The research is an example of GIS-KBS integration in which the elements of KBS techniques are actually integrated with GIS. The idea of the prototype KBGIS system design was to put the model, data, domain knowledge, and the system's knowledge acquisition and reasoning mechanism and GIS together into a same environment.

scholarly journals Application of Seawater Plant Technology for supporting the Achievement of SDGs in Tarawa, Kiribati

2021 ◽  
Vol 7 (2) ◽  
pp. 136-143
Author(s):  
Mi-Yeon Choi ◽  
Ho Ji ◽  
Ho-Saeng Lee ◽  
Deok-Soo Moon ◽  
Hyeon-Ju Kim
Keyword(s):  
Climate Change ◽  
Local Community ◽  
Pilot Project ◽  
Pacific Island ◽  
Seawater Desalination ◽  
Ocean Engineering ◽  
Degree Of Satisfaction ◽  
Korea Research Institute ◽  
Pacific Island Countries ◽  
The Republic

Pacific island countries, including Kiribati, are suffering from a shortage of essential resources as well as a reduction in their living space due to sea level rise and coastal erosion from climate change, groundwater pollution and vegetation changes. Global activities to solve these problems are being progressed by the UN's efforts to implement SDGs. Pacific island countries can adapt to climate change by using abundant marine resources. In other words, seawater plants can assist in achieving SDGs #2, #6 and #7 based on SDGs #14 in these Pacific island countries. Under the auspice of Korea International Cooperation Agency (KOICA), Korea Research Institute of Ships and Ocean Engineering (KRISO) established the Sustainable Seawater Utilization Academy (SSUA) in 2016, and its 30 graduates formed the SSUA Kiribati Association in 2017. The Ministry of Oceans and Fisheries (MOF) of the Republic of Korea awarded ODA fund to the Association. By taking advantage of seawater resource and related plants, it was able to provide drinking water and vegetables to the local community from 2018 to 2020. Among the various fields of education and practice provided by SSUA, the Association hope to realize hydroponic cultivation and seawater desalination as a self-support project through a pilot project. To this end, more than 140 households are benefiting from 3-stage hydroponics, and a seawater desalination system in connection with solar power generation was installed for operation. The Association grows and supplies vegetable seedlings from the provided seedling cultivation equipment, and is preparing to convert to self-support business from next year. The satisfaction survey shows that Tarawa residents have a high degree of satisfaction with the technical support and its benefits. In the future, it is hoped that SSUA and regional associations will be distributed to neighboring island countries to support their SDGs implementations.

scholarly journals An Experimental Assessment of Extreme Wave Evaluation by Integrating Model and Wave Buoy Data

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1201
Author(s):  
Ferdinando Reale ◽  
Fabio Dentale ◽  
Pierluigi Furcolo ◽  
Angela Di Leo ◽  
Eugenio Pugliese Carratelli
Keyword(s):  
Wave Model ◽  
Return Time ◽  
Design Tool ◽  
Data Series ◽  
Model Data ◽  
Ocean Engineering ◽  
Extreme Wave ◽  
Correct Estimation ◽  
Buoy Data

Calculating the significant wave height (SWH) in a given location as a function of the return time is an essential tool of coastal and ocean engineering; such a calculation can be carried out by making use of the now widely available weather and wave model chains, which often lead to underestimating the results, or by means of in situ experimental data (mostly, wave buoys), which are only available in a limited number of sites. A procedure is hereby tested whereby the curves of extreme SWH as a function of the return time deriving from model data are integrated with the similar curves computed from buoy data. A considerable improvement in accuracy is gained by making use of this integrated procedure in all locations where buoy data series are not available or are not long enough for a correct estimation. A useful and general design tool has therefore been provided to derive the extreme value SWH for any point in a given area.

Study on Friction Characteristics Between Ice and Various Rough Plates

2015 ◽  
Author(s):  
Seong-Rak Cho ◽  
Jung-Seok Ha ◽  
Seong-Yeop Jeong ◽  
Kuk-Jin Kang
Keyword(s):  
Sea Ice ◽  
Friction Force ◽  
Early Stage ◽  
Roughness Parameters ◽  
Ocean Engineering ◽  
Friction Characteristics ◽  
Arctic Regions ◽  
Ice Friction ◽  
Korea Research Institute ◽  
Research Institute

Ice is a very particular material that does not obey Amonton’s law of friction. Research on frictional phenomena between sea ice and ice-class vessels or platforms in arctic regions is still in its early stage, even though ships and platforms are greatly influenced and moved by the friction force of sea ice. In this paper, various friction tests were carried out, using freshwater ices and model ices in the Korea Research Institute of Ships and Ocean Engineering (KRISO) ice tank, to find the fundamental friction characteristics of ice and to estimate accurate ice friction force between ship and sea ice. As a result, we not only evaluated a painting method by using matting powders for ice-breaking ship models, but also found that the friction with an ice depends on the fundamental roughness and the supplemental roughness of material by measuring the roughness parameters of the plates. This study is intended to contribute to the understanding of the friction characteristics with ice.

scholarly journals Experimental Investigation on Structural Responses of a Partially Submerged 2D Flat Plate with Hammering and Breaking Waves for Numerical Validation

2021 ◽  
Vol 9 (6) ◽  
pp. 621
Author(s):  
Yoon-Jin Ha ◽  
Byoung-Jae Park ◽  
Yun-Ho Kim ◽  
Kang-Su Lee
Keyword(s):  
Breaking Waves ◽  
Time Interval ◽  
Breaking Wave ◽  
Ocean Engineering ◽  
Flat Plates ◽  
Validation Data ◽  
Air Bubble ◽  
Wave Flume ◽  
Structural Responses ◽  
Korea Research Institute

In this study, experiments were conducted to provide validation data for numerical simulations. Model tests were conducted in a 2D wave flume at the Korea Research Institute of Ships and Ocean Engineering (KRISO). A series of hammering tests for two flat plates with different lengths under dry and partially wet conditions were performed to investigate the vibrating frequencies in each mode. Thereafter, breaking wave tests were performed using the focusing wave method. Repetitive tests were performed five times in each condition. The repetitive test results showed good agreement in each case, and the frequencies for each mode of the two flat plates were numerically calculated. In addition, the wave and air bubble frequencies were captured unlike in the hammering tests. The frequencies for each mode, strain and time interval from the experiments for two flat plates were organized, and the data for validation of the numerical simulation were provided.

Boosting Ship Efficiency

2010 ◽  
Author(s):  
Oskar Levander
Keyword(s):  
Energy Efficiency ◽  
Life Cycle Cost ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Power Demand ◽  
Reduce Fuel Consumption ◽  
Reduce Emissions ◽  
Energy Efficiency Design Index ◽  
Propulsion Power

Ship efficiency has become an increasingly important subject for ship designers and owners. Both the predicted high cost of fuel in the future and the need to reduce emissions is driving this strive for improved efficiency. IMO is also seeking measures to reduce the CO2 emissions from ships and their proposed Energy Efficiency Design Index (EEDI) aims at ensuring that future vessels will be more efficient. Two ship concepts, a large RoRo vessel and a Cruise ferry, have been developed to highlight different technologies that can be used to improve efficiency. The designs show that the power demand can be reduced significantly with already basic naval architecture methods. Optimization of main dimensions for life cycle cost rather than building cost alone can give large savings. Also new propulsion concepts, such as triple shaft lines or Wing thrusters yield clear propulsion power savings. Other measures to reduce fuel consumption, such as waste heat recovery and wind power also show big gains.

scholarly journals Analysis and Assessment of Measurements Results of Electric Power Demand in a Model Vacuum-assisted Moulding Installation

2012 ◽  
Vol 12 (4) ◽  
pp. 135-140
Author(s):  
K. Smyksy ◽  
R. Wrona ◽  
M. Brzeziński ◽  
E. Ziółkowski
Keyword(s):  
Electric Power ◽  
Numerical Procedure ◽  
Practical Method ◽  
Vacuum System ◽  
Power Demand ◽  
System A ◽  
Vacuum Moulding ◽  
Instantaneous Current ◽  
Instantaneous Values ◽  
Mathematical Relationships

Abstract In this article the main problems related with the proper choice of the design and operation parameters of vacuum installation in vacuum moulding system have been discussed. In such system a vacuum are generated using electric-driven vacuum pumps. The aim of the experiment is to evaluate the performance of a vacuum system basing on registered plots of selected electric power parameters of the power-supplying system of the pumps with parallel measurements instantaneous values of pressure in selected points of model stand. The measurements system for power-supply unit has incorporated the recorders of instantaneous current and voltage values. Following the suitable numerical procedure, the experimental data are analysed to yield mathematical relationships between the variations of the generated vacuum pressure levels and variations of selected electric power parameters. According to the authors, the applied measurements system of the parameters of a vacuum-assisted installation may become an effective and easy practical method of evaluating the performance of such installations, used also in industry.

scholarly journals Experimental and Numerical Analysis of Wave Drift Force on KVLCC2 Moving in Oblique Waves

2021 ◽  
Vol 9 (2) ◽  
pp. 136
Author(s):  
Min Guk Seo ◽  
Yoon Jin Ha ◽  
Bo Woo Nam ◽  
Yeongyu Kim
Keyword(s):  
Numerical Analysis ◽  
Ocean Engineering ◽  
Validation Data ◽  
Wave Drift ◽  
Motion Responses ◽  
Direct Pressure ◽  
Korea Research Institute ◽  
Drift Force ◽  
Wave Drift Forces ◽  
Drift Forces

In this study, experimental and numerical methods were applied to estimate surge and sway wave drift forces and yaw drift moment acting on KVLCC2, advancing in oblique wave. An experiment was carried out in the ocean engineering basin of the Korea Research Institute of Ships and Ocean Engineering (KRISO). A series of regular wave tests under various heading conditions were conducted to investigate ship motion responses and wave drift forces. A Rankine panel method based on potential flow was adopted in the numerical analysis, and the direct pressure integration method that integrates second-order pressure on the hull surface was applied to compute wave drift force. Through this study, validation data of wave drift force acting on KVLCC2 was established, and the computation capability of the potential-based numerical method was systematically analyzed.

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