Development of a Ship Performance Simulator in Actual Seas

2015 ◽  
Author(s):  
Masaru Tsujimoto ◽  
Naoto Sogihara ◽  
Mariko Kuroda ◽  
Akiko Sakurada
Keyword(s):  
Energy Efficiency ◽  
Fuel Consumption ◽  
Hydrodynamic Performance ◽  
Wave Forces ◽  
Ship Hydrodynamic ◽  
Main Engine ◽  
Ship Performance ◽  
Actual Seas ◽  
Ship Speed ◽  
Drift Forces

Greenhouse gas shall be reduced from shipping sector. For that purpose the regulation of EEDI (energy efficiency design index for new ships) and SEEMP (ship energy efficiency management plan) were entry into force from 2013. In order to improve energy efficiency of ships in service it is necessary to predict the fuel consumption in actual seas. In order to reduce GHG emission from ships, a Vessel Performance Simulator in Actual Seas has been developed. It simulates ship speed and fuel consumption at steady condition by using weather data and designated engine revolution. Physical models for hull, propeller, rudder and engine are used in the simulator. Especially steady wave forces, wind forces, drift forces, steering forces and engine/governor model are important factor for the estimation. The fuel consumption should be evaluated combined the ship hydrodynamic performance with the engine/governor characteristics. Considering the external forces by winds and waves, the operation point of the main engine is important for the estimation, since the torque limit and the other limit of the engine/governor are affected to the ship hydrodynamic performance. To prevent the increase of fuel consumption in service, the engine control system by the Fuel Index has been applied to present ships. In rough weather condition the revolution of the main engine is reduced to lower revolution by the Fuel Index limit. It causes the large decrease of ship speed but reduces the fuel consumption due to reduction of engine revolution. Using the simulator the navigation performance of a container ship, a RoRo vehicle carrier and a bulk carrier is simulated along the route. In this paper following contents are discussed; 1) evaluation of the physical model; steady wave forces, wind forces, drift forces, steering forces and engine/governor model, 2) simulation and validation of the physical model by tank tests and on-board measurements and 3) effectiveness of the ship performance simulator for GHG reduction.

Development of a Calculation Method for Fuel Consumption of Ships in Actual Seas With Performance Evaluation

2013 ◽  
Author(s):  
Masaru Tsujimoto ◽  
Mariko Kuroda ◽  
Naoto Sogihara
Keyword(s):  
Energy Efficiency ◽  
Fuel Consumption ◽  
Calculation Method ◽  
Weather Condition ◽  
Hydrodynamic Performance ◽  
Added Resistance ◽  
Operating Limits ◽  
Ship Hydrodynamic ◽  
Main Engine ◽  
Actual Seas

Greenhouse gas shall be reduced from shipping sector. For that purpose the regulation of EEDI (energy efficiency design index for new ships) and SEEMP (ship energy efficiency management plan) have been entry into force from 2013. In order to improve the energy efficiency in ship operation it is necessary to predict the fuel consumption accurately. In actual seas the wave effect is the dominant component of the external forces. In particular it is well known the bow shape above water affects the added resistance in waves. To reflect the effect of the bow shape a method which takes into account the result of simplified tank tests is proposed here. Using the results of tank tests the effect of the bow shape above water can be evaluated with accuracy as well as with robustness. Regarding to the fuel consumption it should be evaluated by combining the ship hydrodynamic performance with the engine characteristics. Especially the operating limits of the main engine, such as the torque limit and the over load protection, are affected to the ship hydrodynamic performance. In rough weather condition the revolution of the main engine will be reduced to be below the operating limits of the engine. This causes the large decrease of ship speed. To prevent the increase of fuel consumption, a control system by Fuel Index as an index of fuel injection has been applied to some ships. The calculation method for the fuel consumption by using Fuel Index is presented. In this paper following contents are reported; 1) development of a calculation method for the added resistance due to waves combined with the simplified tank tests in short waves, 2) comparison of the calculation method with onboard measurement, 3) development of a calculation method for the fuel consumption considering the engine operating mode in actual seas and 4) comparison of the method with onboard measurement of a container ship. From these investigations the availability of the present method is confirmed.

scholarly journals Dynamic Prediction and Optimization of Energy Efficiency Operational Index (EEOI) for an Operating Ship in Varying Environments

2019 ◽  
Vol 7 (11) ◽  
pp. 402 ◽  
Author(s):  
Chao Sun ◽  
Haiyan Wang ◽  
Chao Liu ◽  
Ye Zhao
Keyword(s):  
Genetic Algorithm ◽  
Energy Efficiency ◽  
Fuel Consumption ◽  
Dynamic Optimization ◽  
Consumption Rate ◽  
Connection Weight ◽  
Fuel Consumption Rate ◽  
Operational Index ◽  
Main Engine ◽  
Ship Speed

The demands for lower Energy Efficiency Operational Index (EEOI) reflect the requirements of international conventions for green shipping. Within this context it is believed that practical solutions for the dynamic optimization of a ship’s main engine and the reduction of EEOI in real conditions are useful in terms of improving sustainable shipping operations. In this paper, we introduce a model for dynamic optimization of the main engine that can improve fuel efficiency and decrease EEOI. The model considers as input environmental factors that influence overall ship dynamics (e.g., wind speed, wind direction, wave height, water flow speed) and engine revolutions. Fuel consumption rate and ship speed are taken as outputs. Consequently, a genetic algorithm is applied to optimize the initial connection weight and threshold of nodes of a neural network (NN) that is used to predict fuel consumption rate and ship speed. Navigation data from the training ship “YUMING” are applied to train the network. The genetic algorithm is used to optimize engine revolution and obtain the lowest EEOI. Results show that the optimization method proposed may assist with the prediction of lower EEOI in different environmental conditions and operational speed.

Detailed Study on the Behavior of Ships in Very Short Waves

2020 ◽  
Author(s):  
Saori Yokota ◽  
Mariko Kuroda ◽  
Ryohei Fukasawa ◽  
Hiroki Ohba ◽  
Masaru Tsujimoto
Keyword(s):  
Sensitivity Analysis ◽  
Fuel Consumption ◽  
Added Resistance ◽  
Regular Waves ◽  
Short Waves ◽  
Added Resistance In Waves ◽  
Tank Test ◽  
Ship Performance ◽  
Ship Operation ◽  
Actual Seas

Abstract Considering the sea conditions in which a large ship encountered in operation, the ship’s behavior in very short waves is important. However, the evaluation of the ship performance in very short waves was not enough validated by tank tests. Because it is difficult to generate waves with enough accuracy due to the performance of the wave generator. In this paper, it is shown that tank tests of added resistance in the regular waves including the very short waves are conducted in the Actual Sea Model Basin at National Maritime Research Institute, MPAT for DTC container ship and accurate results are obtained. The test results are compared with the benchmarks published by SHOPERA (Energy Efficient Safe SHip OPERAtion). In addition, three curves of the added resistance in the regular waves based on the results of the tank test are compared and the sensitivity analysis of energy efficiency is discussed. In the sensitivity analysis, the performance simulator for ships in actual seas (VESTA) is used, and a comparison is carried out for the fuel consumption calculated from the frequency response of each added resistance in waves. As a result, it is found that the tendency in added resistance in very short waves affects the fuel consumption and the decrease of ship speed.

Marine Engine-Centered Data Analytics for Ship Performance Monitoring

2017 ◽  
Vol 139 (2) ◽  
Author(s):  
Lokukaluge P. Perera ◽  
Brage Mo
Keyword(s):  
Energy Efficiency ◽  
Data Analytics ◽  
Performance Monitoring ◽  
Clustering Algorithm ◽  
Gaussian Mixture ◽  
Control Measures ◽  
Marine Engine ◽  
Operating Regions ◽  
Main Engine ◽  
Ship Performance

This study proposes marine engine centered data analytics as a part of the ship energy efficiency management plan (SEEMP). The SEEMP enforces various emission control measures to improve ship energy efficiency by considering vessel performance and navigation data. The proposed data analytics is developed in the engine-propeller combinator diagram (i.e., one propeller shaft with a direct drive main engine). Three operating regions from the initial data analysis are under the combinator diagram noted to capture the shape of these regions by the proposed data analytics. The data analytics consists of implementing Gaussian mixture models (GMMs) to classify the most frequent operating regions of the main engine. Furthermore, the expectation maximization (EM) algorithm calculates the parameters of GMMs. This approach, also named data clustering algorithm, facilitates an iterative process for capturing the operating regions of the main engine (i.e., in the combinatory diagram) with the respective mean and covariance matrices. Hence, these data analytics can monitor ship performance and navigation conditions with respect to engine operating regions as a part of the SEEMP. Furthermore, development of advanced mathematical models for ship performance monitoring within the operational regions (i.e., data clusters) of marine engines is expected.

ANALISA PERFORMA KAPAL KM. CIREMAI DENGAN MODIFIKASI PENAMBAHAN PROPELLER HUB CAPS FIN DENGAN METODE EKSPERIMEN

2020 ◽  
Vol 21 (1) ◽  
pp. 11-15
Author(s):  
Suharto Suharto ◽  
Sulaiman Sulaiman
Keyword(s):  
Fuel Consumption ◽  
Flow Model ◽  
Propulsion Systems ◽  
Sea Trial ◽  
Before And After ◽  
Main Engine ◽  
Ship Propeller ◽  
Ship Speed ◽  
Consumption Efficiency ◽  
Selection Of

The various ship propulsion models there are several considerations in the selection to be applied to the ship, such considerations are required in the planning of the ship's propulsion. With the addition of propeller hub caps fin is expected to deliver a flow model that supports the performance of propulsion systems on ship. The purpose to analyzes the best performance of the propeller shaft engine, representing a comparison of fuel consumption efficiency, as well as ship speed based on the addition of propeller hub caps fin on MV. CEREMAI. Method used was conducted experimentally to determine the performance of the ship's engines before and after using energo pro fin (propeller hub caps fin) with sea trial. Result shows  2% reduction in fuel consumption on the portside main engine and 3% starboard main engine. As well as enabling increased operational speed of KM ships. CIREMAI at 12% with the same rpm round. So selection of ship propeller types affects the performance of enegro profin (propeller hub caps fin).

Influence of Ship Behaviour in a Seaway on CO2 Emissions

2013 ◽  
Author(s):  
Jasna Prpić-Oršić ◽  
Odd Magnus Faltinsen ◽  
Tomislav Mrakovčić
Keyword(s):  
Carbon Dioxide ◽  
Fuel Consumption ◽  
Co2 Emissions ◽  
Irregular Waves ◽  
Computational Time ◽  
Engine Fuel ◽  
Added Resistance ◽  
Regular Waves ◽  
Actual Seas ◽  
Ship Speed

A reliable prediction of attainable ship speed at actual seas is essential from economical and environmental aspects. At this paper a methodology for estimating the attainable speed and related fuel consumption and carbon dioxide (CO2) emissions in moderate and severe sea is proposed. The irregular sea is handled as a series of regular waves with different amplitudes and frequencies. The added resistance in regular waves is obtained by either a direct pressure integration method or an asymptotic small wavelength formula. The in-and-out-of-water-effect and ventilation of a propeller in severe seas is accounted for by a quasi-steady averaging of experimental data for different propeller submergences. The propulsion results for regular waves are used in simulating results in irregular waves. It is shown that for higher sea states this effect has much more influence on the speed loss than the added resistance in waves. The speed loss is calculated by taking into account the engine and propeller performance in actual seas as well as the mass inertia of the ship. The numerical model used for main propulsion engine modeling is based on a zero-dimensional model of an internal combustion engine. The main propulsion engine is represented by number of control volumes interconnected with links for mass and energy transfer between them. This model provides excellent prediction of engine dynamic response during transients with rather short computational time. Also, engine fuel consumption can be precisely determined which represents the basic presumption for estimation of carbon-dioxide emission. Furthermore, use of such model can be extended to determination of the lowest fuel oil consumption strategy for given sea condition and ship speed with resulting lowest possible CO2 emissions. The attainable ship speed is obtained as time series. Correlation of speed loss with sea states allows predictions of propulsive performance in actual seas.

A Statistical Approach to Ship Fuel Consumption Monitoring

2015 ◽  
Vol 59 (03) ◽  
pp. 162-171 ◽  
Author(s):  
Dario Bocchetti ◽  
Antonio Lepore ◽  
Biagio Palumbo ◽  
Luigi Vitiello
Keyword(s):  
Energy Efficiency ◽  
Fuel Consumption ◽  
Statistical Approach ◽  
Prediction Interval ◽  
Management Plan ◽  
Efficiency Improvement ◽  
Co2 Emission Reduction ◽  
Technical Management ◽  
Energy Efficiency Improvement ◽  
Ship Performance

The reduction of the environmental impact imposed by Kyoto Protocol and the growth of competitiveness imposed by the shipping market have urged shipping companies to pay increasing attention to ship energy efficiency improvement and CO2 emission reduction. According to the Ship Energy Efficiency Management Plan (SEEMP) recommended by the International Maritime Organization (IMO), the main scope of this article is in fact to overcome the deterministic limits of the monitoring systems installed in modern ships and support technical management in decision making based on large navigation databases. The proposed statistical approach is founded on a multiple linear regression and allows for both pointwise and interval predictions of the fuel consumption. At the end of each voyage, the model can be used to alert management for a possible change in ship performance in all those situations where the actual fuel consumption lies outside the prediction interval. Moreover, the model can also be utilized to quantify the contribution to the fuel consumption due to the hull and propeller fouling, which is particularly profitable for shipping companies and operators to claim for carbon credits after a specific improvement operation.

Development of a Weather Adaptive Navigation System Considering Ship Performance in Actual Seas

2006 ◽  
Author(s):  
Masaru Tsujimoto ◽  
Katsuji Tanizawa
Keyword(s):  
Fuel Consumption ◽  
Navigation System ◽  
Weather Forecast ◽  
Weather Data ◽  
Vertical Acceleration ◽  
Augmented Lagrange Multiplier ◽  
Ship Performance ◽  
Actual Seas ◽  
Ship Safety ◽  
Augmented Lagrange Multiplier Method

Aiming to reduce fuel consumption and CO2 emission a new navigation system called WAN has been developed. The system provides optimum route and engine revolution with constraints of schedule and seakeeping criteria. In this paper, simulations of a container liner on transpacific route are demonstrated using WAN. Weather data used here are composed of 8 items; significant height, period and peak direction of wind wave, significant height, period and peak direction of swell, and mean speed and direction of wind. Ship responses; i.e. ship speed, fuel consumption and vertical acceleration at F.P., are calculated based upon the enhanced unified theory. To optimize route and engine revolution the augmented Lagrange multiplier method is applied. The objective function of minimization is fuel consumption with constraints of the schedule and the service limit. From the simulations, the effectiveness of WAN resulted very high and it is shown that the reduction of the fuel becomes 26.1% on average. Concerning the schedule keeping, accuracy of weather forecast must be examined. The influence on the system is evaluated using two kinds of weather data; one is a forecast received at departure and the other is the dataset extracted from the sequential forecasts of every 24 hours. From the simulations it is found that the fluctuation of fuel consumption due to updating the weather forecast is much smaller than the reduction of the fuel by WAN. However, from the viewpoint of ship safety, it is necessary to execute the system again whenever the weather forecast updated.

scholarly journals Numerical Investigation on Hydrodynamic Performance of a Portable AUV

2021 ◽  
Vol 9 (8) ◽  
pp. 812
Author(s):  
Lin Hong ◽  
Renjie Fang ◽  
Xiaotian Cai ◽  
Xin Wang
Keyword(s):  
Numerical Investigation ◽  
Dynamic Model ◽  
Autonomous Underwater Vehicle ◽  
Dynamic Performance ◽  
Plane Motion ◽  
Hydrodynamic Performance ◽  
Wave Forces ◽  
Modeling And Control ◽  
Experiment Platform ◽  
Cfd Method

This paper conducts a numerical investigation on the hydrodynamic performance of a portable autonomous underwater vehicle (AUV). The portable AUV is designed to cruise and perform some tasks autonomously in the underwater world. However, its dynamic performance is strongly affected by hydrodynamic effects. Therefore, it is crucial to investigate the hydrodynamic performance of the portable AUV for its accurate dynamic modeling and control. In this work, based on the designed portable AUV, a comprehensive hydrodynamic performance investigation was conducted by adopting the computational fluid dynamics (CFD) method. Firstly, the mechanical structure of the portable AUV was briefly introduced, and the dynamic model of the AUV, including the hydrodynamic term, was established. Then, the unknown hydrodynamic coefficients in the dynamic model were estimated through the towing experiment and the plane-motion-mechanism (PMM) experiment simulation. In addition, considering that the portable AUV was affected by wave forces when cruising near the water surface, the influence of surface waves on the hydrodynamic performance of the AUV under different wave conditions and submerged depths was analyzed. Finally, the effectiveness of our method was verified by experiments on the standard models, and a physical experiment platform was built in this work to facilitate hydrodynamic performance investigations of some portable small-size AUVs.

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