Application of a variable-fidelity hydrodynamic optimization strategy in fuel-efficient ship design

2018 ◽  
Vol 233 (18) ◽  
pp. 6293-6306
Author(s):  
Hassan Zakerdoost ◽  
Hassan Ghassemi
Keyword(s):  
Carbon Dioxide ◽  
Fuel Consumption ◽  
Early Stage ◽  
Carbon Dioxide Emission ◽  
Cost Effective ◽  
Ship Design ◽  
Operating Conditions ◽  
Fuel Oil ◽  
Optimization Strategy ◽  
Variable Fidelity

Now more than ever, the amount of fuel a ship consumes and the amount of carbon dioxide emitted from a ship have attracted many researchers’ attention towards efficient and cost-effective ship designs. Therefore, fuel consumption and carbon dioxide emission reduction are two main targets of almost all industrial and scientific communities. The key scope of this article is to describe an innovative methodology for the variable-fidelity design optimization of a ship’s hull-propeller system under multiple operating conditions in early-stage ship design. Non-uniform rational basis spline technique and the efficient multi-objective evolutionary algorithm based on decomposition are, respectively, used to generate variants of hull-propeller designs and minimize the fuel consumption and carbon dioxide emission as objective functions of the proposed problem. The variable fidelity numerical solvers are also applied for the hydrodynamic evaluation of the design performance during optimization. Three different specific fuel oil consumption data provided by the engine manufacturers Wartsila, MAN B&W and Caterpillar are used to optimize a medium-sized bulk carrier driven by a well-known propeller as the initial design. The numerical results show an improvement in performance of the optimal hull-propeller designs.

scholarly journals Motor Current Signature Analysis-Based Permanent Magnet Synchronous Motor Demagnetization Characterization and Detection

Machines ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 35
Author(s):  
Manel Krichen ◽  
Elhoussin Elbouchikhi ◽  
Naourez Benhadj ◽  
Mohamed Chaieb ◽  
Mohamed Benbouzid ◽  
...  
Keyword(s):  
Permanent Magnet ◽  
Permanent Magnets ◽  
Early Stage ◽  
Permanent Magnet Synchronous Motor ◽  
Cost Effective ◽  
Operating Conditions ◽  
Signature Analysis ◽  
Motor Current ◽  
Motor Current Signature Analysis ◽  
Current Signature

Neodymium-boron (NdFeB) permanent magnets (PMs) have been widely studied in the past years since they became the material of choice in permanent magnet synchronous machines (PMSMs). Although NdFeB PMs have a better energy density than other types of magnets and are cost-effective, their magnetization is very sensitive to the PMSM operating conditions, in particular temperature, where the irreversible demagnetization degree increases over time. Therefore, it is important to characterize and diagnose demagnetization at an early stage. In this context, this paper proposes a two-step analysis study dealing with both uniform and partial demagnetization. A 2D finite element method-based (FEM) approach is used for demagnetization characterization, and then a PMSM motor current signature analysis (MCSA) approach, based on fast Fourier transform (FFT), is considered where fault cases harmonics are considered as faults indices to detect demagnetization. In some situations, the proposed two-step approach achieved results that clearly allow distinguishing and characterizing demagnetization. Indeed, a local demagnetization introduces specific sub-harmonics while a uniform demagnetization leads to the current amplitude increase for a given torque.

Minimal Time Route Computation for Ships with Pre-Specified Voyage Fuel Consumption

2008 ◽  
Vol 61 (4) ◽  
pp. 723-733 ◽  
Author(s):  
S. J. Bijlsma
Keyword(s):  
Carbon Dioxide ◽  
Air Pollution ◽  
Fuel Consumption ◽  
Greenhouse Effect ◽  
Fuel Oil ◽  
Air Emissions ◽  
Combustion Engines ◽  
Heavy Fuel Oil ◽  
Additional Method ◽  
Minimal Time

The air pollution caused by the use of heavy fuel oil in shipping is a growing problem that is drawing increased attention. Methods have been developed to reduce air emissions from ships, more or less aimed at the choice of fuel and the related air emissions. However, the emissions of particulates, sulphur and carbon dioxide, which contribute to the greenhouse effect are not only related to the choice of fuel but also to the amount of fuel consumed in the combustion engines. This paper proposes an additional method that can contribute to the reduction of the air pollution from ships by decreasing the fuel consumption. This is done by specifying the amount of fuel that can be consumed on a specific ocean crossing and by computing a minimal-time route for that given amount of fuel, so decreasing the fuel consumption in a verifiable way.

Reducing Detail Design and Construction Work Content by Cost-Effective Decisions in Early Stage Naval Ship Design

2014 ◽  
Author(s):  
Robert G. Keane ◽  
Laury Deschamps ◽  
Steve Maguire
Keyword(s):  
Early Stage ◽  
Cost Effective ◽  
Ship Design ◽  
Defense Acquisition ◽  
Design Decisions ◽  
Stage Design ◽  
Work Content ◽  
Detail Design ◽  
Naval Ship ◽  
Early Stage Design

The Office of the Under Secretary of Defense, Acquisition, Technology and Logistics (AT&L) recently presented analyses of cost and schedule growth on Major Defense Acquisition Programs (MDAPs)over the last 20 years (2013, 2014). For naval ships, AT&L (2013) concluded that contract work content growth (not capability growth) dominates total cost growth statistically. In addition, costs-over-target are significant and reflect poor cost estimation or faulty framing assumptions. AT&L (2014) also concluded prices on fixed-price contracts are only “fixed” if the contractual work content remains fixed, but this is often not the case. The authors show that under-sizing the ship during concept design studies increases ship outfit density and adds complexities to the design. These early stage design decisions on sizing the ship are a major contributor to unnecessary work content growth later in Detail Design and Construction (DD&C) that cannot be eliminated no matter how productive the shipbuilder. However, new ship design methods are being developed and integrated with legacy physics-based design and analysis tools into a Rapid Ship Design Environment (RSDE)that will enable a more rational process for initially sizing ships. The authors also identify the need for early stage design measures of complexity and ship costing tools that are more sensitive to these measures, and proposed solutions that will aid decision-makers in reducing DD&C work content by making cost-effective design decisions in early stage naval ship design.

Influence of test fuel properties and composition on UNECE R101 CO2 and fuel economy valuation

2015 ◽  
Vol 4 (4) ◽  
Author(s):  
A. Parker
Keyword(s):  
Carbon Dioxide ◽  
Fuel Consumption ◽  
Fuel Economy ◽  
Co2 Emission ◽  
Energy Demand ◽  
Energy Content ◽  
Carbon Dioxide Emission ◽  
Fuel Properties ◽  
Test Fuel ◽  
Lower Heating

AbstractCO2 emission and fuel consumption of passenger cars is now assessed by using a simplistic procedure measuring the emission during a test performed without any control of the fuel properties and computing the fuel consumption through an unsophisticated formula. As pump gasoline and diesel fuels are refinery products mixture of many different hydrocarbons, and in case of gasoline may also contain a significant amount of oxygenates, the fuel properties, including the density, carbon and energy content may strongly vary from one pump fuel to the other. Being the specific test fuels carefully selected by the car manufacturers and everything but randomly chosen pump fuels, the claimed CO2 emission and fuel economy figures may differ largely from the certification values. I show from the analysis of the 2014 UK government data for 2358 diesel and 2103 petrol vehicles how same volumes of only theoretically same pump fuels used during the certification test by the cars manufacturers unfortunately do not produce the same carbon dioxide emission, and very likely do not have the same energy content. The CO2 emission per liter of diesel fuel is shown to oscillate froma maximum of 3049 g to a minimum of 2125 g, with an average of 2625 g, froma +16.13% to a -19.06% of the average. TheCO2 emission per liter of petrol fuel is shown to oscillate even more from a maximum of 3735 g to a minimum of 1767 g with an average of 2327 g, from a +60.48% to a -24.05% of the average. The proposed solution is to center the assessment on the energy demand by measuring with accuracy the mass of fuel consumed and the fuel properties of the test fuel starting from the lower heating. The corrected fuel consumption and the corrected carbon dioxide emission to mention from the test are then computed by using pure hydrocarbon reference fuels for diesel and petrol having a given lower heating value and a given hydrocarbon composition. Alternatively, exactly the same test fuel should be used by all the manufacturers.

A Study of the Effects of Biofuel Use on Piston Lubrication During Fuel Post Injection in a Direct Injection Diesel Engine

2012 ◽  
Vol 134 (6) ◽  
Author(s):  
Koji Kikuhara ◽  
Akihiro Shibata ◽  
Akemi Ito ◽  
Dallwoo Kim ◽  
Yasuhiro Ishikawa ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Diesel Engine ◽  
Diesel Engines ◽  
Carbon Dioxide Emissions ◽  
Operating Conditions ◽  
Fuel Oil ◽  
Cylinder Wall ◽  
Post Injection ◽  
Friction Forces ◽  
Lubrication Condition

The reduction of both exhaust gases and carbon dioxide emissions is necessary to meet future emissions regulations for diesel engines. Exhaust after-treatment devices are gradually being applied to diesel engines to reduce exhaust gases. Diesel particulate filters (DPF), an after-treatment device for diesel engines, in some cases require fuel post injection for regeneration. Post injection is usually conducted at the midpoint of the expansion stroke, and therefore causes fuel adhesion to the cylinder wall. However, using biofuels in a diesel engine is an effective way of reducing carbon dioxide emissions. It is well known that biofuels are chemically unstable, but the effects of biofuels on piston lubrication condition have not been thoroughly studied. In this study, piston lubrication condition during post injection in a single cylinder DI diesel engine using biofuel was investigated. Piston and ring friction forces were measured under engine operating conditions by means of a floating liner device to investigate the lubrication condition of the piston and rings. Both light fuel oil and biofuel were used in the measurements, with rapeseed methyl ester (RME) being used as the biofuel. Lubricating oil on the cylinder wall was also sampled under engine operating conditions, and the effect of post injection on fuel adhesion to the cylinder wall was analyzed. It was found that the effect of post injection on fuel adhesion to the cylinder wall was remarkable around the top dead center (TDC), and the fuel dilution rate reached approximately 90%. The results of the measurement of the piston friction forces showed that post injection caused an increase in the friction forces at the compression TDC (CTDC) in the cases of both RME and light fuel oil, and the friction forces at CTDC increased according to the delay of the post injection timing. The increase in the piston friction forces was moderate in the case of RME. It seems that the higher viscosity and the oiliness of RME suppressed the increase in piston friction forces at TDC. The following effects were found in this study. Fuel post injection caused fuel adhesion to the cylinder wall. Such phenomena affected the lubrication condition of the piston. In the case of RME, the increase in the piston friction forces caused by post injection was smaller than that of light fuel oil, but the effects on piston lubrication condition in the case of using other biofuels needs to be investigated.

Reducing Detail Design and Construction Work Content by Cost-Effective Decisions in Early-Stage Naval Ship Design

2016 ◽  
Vol 32 (02) ◽  
pp. 110-123
Author(s):  
Robert G. Keane ◽  
Laurent Deschamps ◽  
Steve Maguire
Keyword(s):  
Early Stage ◽  
Cost Effective ◽  
Ship Design ◽  
Defense Acquisition ◽  
Design Decisions ◽  
Stage Design ◽  
Work Content ◽  
Detail Design ◽  
Naval Ship ◽  
Early Stage Design

The Office of the Under Secretary of Defense, Acquisition, Technology, and Logistics (AT&L) recently presented analyses of cost and schedule growth on Major Defense Acquisition Programs (MDAPs) over the last 20 years (2013, 2014). For naval ships, AT&L (2013) concluded that contract work content growth (not capability growth) dominates total cost growth statistically. In addition, costs-over-target are significant and reflect poor cost estimation or faulty framing assumptions. AT&L (2014) also concluded prices on fixed-price contracts are only "fixed" if the contractual work content remains fixed, but this is often not the case. We show that under-sizing the ship during concept design studies increases ship outfit density and adds complexities to the design. These early-stage design decisions on sizing the ship are a major contributor to unnecessary work content growth later in Detail Design and Construction (DD&C) that cannot be eliminated no matter how productive the shipbuilder. However, new ship design methods are being developed and integrated with legacy physicsbased design and analysis tools into a Rapid Ship Design Environment (RSDE) that will enable a more rational process for initially sizing ships. We also identify the need for early-stage design measures of complexity and ship costing tools that are more sensitive to these measures, and propose solutions that will aid decision-makers in reducing DD&C work content by making cost-effective design decisions in early-stage naval ship design.

scholarly journals Multi-Objective Predictive Control Optimization with Varying Term Objectives: A Wind Farm Case Study

Processes ◽  
2019 ◽  
Vol 7 (11) ◽  
pp. 778 ◽  
Author(s):  
Clara M. Ionescu ◽  
Constantin F. Caruntu ◽  
Ricardo Cajo ◽  
Mihaela Ghita ◽  
Guillaume Crevecoeur ◽  
...  
Keyword(s):  
Predictive Control ◽  
Wind Farm ◽  
Cost Effective ◽  
Optimality Criteria ◽  
Operating Conditions ◽  
Optimization Strategy ◽  
Multi Objective ◽  
Efficiency Cost

This paper introduces the incentive of an optimization strategy taking into account short-term and long-term cost objectives. The rationale underlying the methodology presented in this work is that the choice of the cost objectives and their time based interval affect the overall efficiency/cost balance of wide area control systems in general. The problem of cost effective optimization of system output is taken into account in a multi-objective predictive control formulation and applied on a windmill park case study. A strategy is proposed to enable selection of optimality criteria as a function of context conditions of system operating conditions. Long-term economic objectives are included and realistic simulations of a windmill park are performed. The results indicate the global optimal criterium is no longer feasible when long-term economic objectives are introduced. Instead, local sub-optimal solutions are likely to enable long-term energy efficiency in terms of balanced production of energy and costs for distribution and maintenance of a windmill park.

scholarly journals Driver Rating: a mobile application to evaluate driver behavior

2021 ◽  
Vol 2 (2) ◽  
pp. 1147-1160
Author(s):  
Nielson S. Trindade ◽  
Artur H. Kronbauer ◽  
Helder G. Aragão ◽  
Jorge Campos
Keyword(s):  
Carbon Dioxide ◽  
Urban Environment ◽  
Fuel Consumption ◽  
Intelligent Transportation Systems ◽  
Mobile Application ◽  
Driver Behavior ◽  
Carbon Dioxide Emission ◽  
Intelligent Transportation ◽  
Transportation Systems

The combination of data from sensors embedded in vehicles and smartphones promises to generate great innovations in intelligent transportation systems. This article presents Driver Rating, a mobile application to evaluate the behavior of drivers based on the data gathered from vehicles´ and smartphones´ sensors. The Driver Rating application analyzes five variables (fuel consumption, carbon dioxide emission, speed, longitudinal acceleration, and transverse acceleration) to evaluate driver´s behaviors while driving. To test the Driver Rating application and identify its potentialities, an experiment was carried out on an urban environment, showing promising results regarding the classification of drivers’ behavior.

Sign in / Sign up

Export Citation Format

Share Document