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Article
Publication date: 20 May 2019

Elie Bertrand Kengne Signe, Abraham Kanmogne, Guemene D. Emmanuel and Lucien Meva’a

The purpose of this paper is contribution to estimate the potential of wind energy in Douala in Cameroon, by modeling and predicting the regime of wind. The paper deals…

Abstract

Purpose

The purpose of this paper is contribution to estimate the potential of wind energy in Douala in Cameroon, by modeling and predicting the regime of wind. The paper deals with the analysis and comparison of seven numerical methods for the assessment of effectiveness in determining the parameters for the Weibull distribution, using wind speed data collected at Douala International Airport in Cameroon, in the period from September 2011 to May 2013, obtained by meteorological equipment belonging to the Laboratory of Energy Research of the Institute of Geological and Mining Research.

Design/methodology/approach

By using ANOVA, root mean square error and chi-square tests to compare the proposed methods, this study aims to determine which methods are effective in determining the parameters of the Weibull distribution for the available data, in an attempt to establish acceptable criteria for better usage of wind power in Douala, which is the economic capital and ought to have prominence in the use of renewable sources for electricity generation in Cameroon.

Findings

The study helps to determine that moment, empirical and energy pattern factor methods used to determine the shape parameter k and the scale parameter c of the Weibull distribution present a better curve fit with the histogram of the wind speed. This fact is clearly validated by means of the statistical tests. But, all the seven methods gave excellent performance. Then, k reaching levels ranging from 3.5 to 5.5 and c range from 1.7 to 2.4.

Originality/value

Then as far as we are concerned, for a significant contribution, it could be more effective to have a model for prediction of wind characteristics using wind data collected per hour, one at least three years. A comparison of results obtained from lots of other methods (seven in this case) is necessary before an efficient discussion. Standard deviations and errors between measured and predicted data must also be presented.

Details

International Journal of Energy Sector Management, vol. 13 no. 4
Type: Research Article
ISSN: 1750-6220

Keywords

Article
Publication date: 6 July 2012

Jaehyun Park, Junglo Park, Juhyung Kim and Jaejun Kim

The purpose of this study is to identify an objective energy performance assessment method in Korea, and to build a building information modelling (BIM) based system that…

1378

Abstract

Purpose

The purpose of this study is to identify an objective energy performance assessment method in Korea, and to build a building information modelling (BIM) based system that can assess the energy performance of buildings.

Design/methodology/approach

The energy performance assessment methods currently used in Korea were first identified via a literature review. A system was then implemented to solve the problem of objectivity. The system was implemented through a data‐based building information model, instead of the existing method of documented two‐dimensional (2D) CAD. In addition, Revit Architecture (a BIM tool), MS Access, and Visual Basic (VB) were used to implement the system. To verify the system's efficiency, it was compared to the existing method by applying both to an actual case (a school facility).

Findings

This study found that the issue of subjectivity in the Korean energy performance assessment method may be resolved with a data‐based BIM.

Originality/value

This study presented the BIM‐EPAS to reduce errors and the time needed to conduct an energy performance assessment. In order to follow a realistic approach, the BIM‐EPAS was applied to an actual assessment case, thereby verifying the system's applicability.

Article
Publication date: 28 December 2018

Fatemeh Ebadi, Mohammad Mardaneh and Akbar Rahideh

This paper aims to show the proposed energy method for inductance calculation is valid for any number of poles, phases and any winding layout.

Abstract

Purpose

This paper aims to show the proposed energy method for inductance calculation is valid for any number of poles, phases and any winding layout.

Design/methodology/approach

A two-dimensional (2-D) analytical energy-based approach is presented to calculate self-inductances and mutual inductances of brushless surface-mounted permanent-magnet machines.

Findings

The proposed calculation procedure is valid for brushless permanent-magnet machines with slotted or slotless stator structure. Comparisons between energy method and flux linkage method are presented based on simulation and experimental results. It shows that the energy method has an excellent agreement with the result obtained from finite element method (FEM) and experimental study.

Originality/value

This paper compares energy-based method with flux linkage method and FEM for inductance calculations in slotless and slotted permanent-magnet motors. The relations for inductance calculation are presented which are obtained based on 2-D analytical representation of magnetic field.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 38 no. 2
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 12 April 2022

Qing-Yun Deng, Shun-Peng Zhu, Jin-Chao He, Xue-Kang Li and Andrea Carpinteri

Engineering components/structures with geometric discontinuities normally bear complex and variable loads, which lead to a multiaxial and random/variable amplitude…

Abstract

Purpose

Engineering components/structures with geometric discontinuities normally bear complex and variable loads, which lead to a multiaxial and random/variable amplitude stress/strain state. Hence, this study aims how to effectively evaluate the multiaxial random/variable amplitude fatigue life.

Design/methodology/approach

Recent studies on critical plane method under multiaxial random/variable amplitude loading are reviewed, and the computational framework is clearly presented in this paper.

Findings

Some basic concepts and latest achievements in multiaxial random/variable amplitude fatigue analysis are introduced. This review summarizes the research status of four main aspects of multiaxial fatigue under random/variable amplitude loadings, namely multiaxial fatigue criterion, method for critical plane determination, cycle counting method and damage accumulation criterion. Particularly, the latest achievements of multiaxial random/variable amplitude fatigue using critical plane methods are classified and highlighted.

Originality/value

This review attempts to provide references for further research on multiaxial random/variable amplitude fatigue and to promote the development of multiaxial fatigue from experimental research to practical engineering application.

Details

International Journal of Structural Integrity, vol. 13 no. 3
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 11 June 2018

Xuefeng Zhou, Li Jiang, Yisheng Guan, Haifei Zhu, Dan Huang, Taobo Cheng and Hong Zhang

Applications of robotic systems in agriculture, forestry and high-altitude work will enter a new and huge stage in the near future. For these application fields, climbing…

Abstract

Purpose

Applications of robotic systems in agriculture, forestry and high-altitude work will enter a new and huge stage in the near future. For these application fields, climbing robots have attracted much attention and have become one central topic in robotic research. The purpose of this paper is to propose an energy-optimal motion planning method for climbing robots that are applied in an outdoor environment.

Design/methodology/approach

First, a self-designed climbing robot named Climbot is briefly introduced. Then, an energy-optimal motion planning method is proposed for Climbot with simultaneous consideration of kinematic constraints and dynamic constraints. To decrease computing complexity, an acceleration continuous trajectory planner and a path planner based on spatial continuous curve are designed. Simulation and experimental results indicate that this method can search an energy-optimal path effectively.

Findings

Climbot can evidently reduce energy consumption when it moves along the energy-optimal path derived by the method used in this paper.

Research limitations/implications

Only one step climbing motion planning is considered in this method.

Practical implications

With the proposed motion planning method, climbing robots applied in an outdoor environment can commit more missions with limit power supply. In addition, it is also proved that this motion planning method is effective in a complicated obstacle environment with collision-free constraint.

Originality/value

The main contribution of this paper is that it establishes a two-planner system to solve the complex motion planning problem with kinodynamic constraints.

Details

Industrial Robot: An International Journal, vol. 45 no. 3
Type: Research Article
ISSN: 0143-991X

Keywords

Article
Publication date: 1 July 2006

Yang Zhao, Jie Sun and Hao Tian

To set up the analytical model of reaction wheel assembly (RWA) by using the other theory and to provide a new method to identify the parameters of the empirical model of RWA.

Abstract

Purpose

To set up the analytical model of reaction wheel assembly (RWA) by using the other theory and to provide a new method to identify the parameters of the empirical model of RWA.

Design/methodology/approach

Setting up the analytical model of RWA using virtual work theory, and presents the energy compensation method. The energy compensation method to improve the computation accuracy of amplitude coefficients of the empirical model of RWA. In the empirical model of RWA, the assumption is that the disturbances consist of discrete harmonics, and the amplitudes is proportion to the square of the wheel speed.

Findings

The errors of amplitude coefficients adopting energy compensation window excel the amplitude spectrum method. The energy compensation method improves the parameters identification accuracy, and provides a new method to set up more accurate empirical disturbance model of RWA.

Practical implications

Providing a valuable identification method of amplitude coefficients of the empirical model of RWA, and improving the accuracy of identification.

Originality/value

Putting forward up the method of energy compensation to identify the amplitude coefficients of the empirical model of RWA, and improving the accuracy. This method is simple, practical for the system design.

Details

Aircraft Engineering and Aerospace Technology, vol. 78 no. 4
Type: Research Article
ISSN: 0002-2667

Keywords

Article
Publication date: 18 July 2019

Zahid Hussain Hulio and Wei Jiang

The purpose of this paper is to investigate wind power potential of site using wind speed, wind direction and other meteorological data including temperature and air…

Abstract

Purpose

The purpose of this paper is to investigate wind power potential of site using wind speed, wind direction and other meteorological data including temperature and air density collected over a period of one year.

Design/methodology/approach

The site-specific air density, wind shear, wind power density, annual energy yield and capacity factors have been calculated at 30 and 10 m above the ground level (AGL). The Weibull parameters have been calculated using empirical, maximum likelihood, modified maximum likelihood, energy pattern and graphical methods to determine the other dependent parameters. The accuracies of these methods are determined using correlation coefficient (R²) and root mean square error (RMSE) values.

Findings

The site-specific wind shear coefficient was found to be 0.18. The annual mean wind speeds were found to be 5.174 and 4.670 m/s at 30 and 10 m heights, respectively, with corresponding standard deviations of 2.085 and 2.059. The mean wind power densities were found to be 59.50 and 46.75 W/m² at 30 and 10 m heights, respectively. According to the economic assessment, the wind turbine A is capable of producing wind energy at the lowest value of US$ 0.034/kWh.

Practical implications

This assessment provides the sustainable solution of energy which minimizes the dependence on continuous supply of oil and gas to run the conventional power plants that is a major cause of increasing load shedding in the significant industrial and thickly populated city of Pakistan. Also, this will minimize the quarrel between the local power producer and oil and gas supplier during the peak season.

Social implications

This wind resource assessment has some important social implications including decreasing the environmental issues, enhancing the uninterrupted supply of electricity and decreasing cost of energy per kWh for the masses of Karachi.

Originality/value

The results are showing that the location can be used for installing the wind energy power plant at the lower cost per kWh compared to other energy sources. The wind energy is termed as sustainable solution at the lowest cost.

Details

International Journal of Energy Sector Management, vol. 14 no. 1
Type: Research Article
ISSN: 1750-6220

Keywords

Article
Publication date: 22 July 2019

Zeki Ayağ and Funda Samanlioglu

Since the demand for energy has dramatically increased in the countries which have fast-growing population and economy, they have faced with a critical problem of how to…

Abstract

Purpose

Since the demand for energy has dramatically increased in the countries which have fast-growing population and economy, they have faced with a critical problem of how to evaluate a set of potential energy sources (i.e. nuclear, natural gas, bio, geothermal, hydro, wind and solar) and choose the ultimate energy source for their needs. On the other hand, this critical problem turns into a multiple-criteria decision-making (MCDM) in the presence of a set of energy source alternatives and evaluation criteria. In literature, there are many MCDM methods introduced to solve for different kinds of problems. The purpose of this paper is to present an integrated approach for evaluating energy sources using fuzzy AHP and GRA, with a case for Turkey.

Design/methodology/approach

In this paper, the analytic hierarchy process (AHP) and grey relational analysis (GRA) methods are used because of their advantages for similar problems. On the other hand, due to the fact that the conventional AHP by a nine-point scale and GRA method using a scale with crisp values can be unable to handle to capture the right judgments of a decision-maker(s), to reflect the vagueness and uncertainty on the judgments of a decision-maker, the fuzzy logic is integrated with the AHP and GRA.

Findings

The contributions of the paper to the literature are given in two dimensions as follows: it presents an integrated approach for complex decision processes with subjective data or vague information; the proposed approach, the fuzzy AHP-GRA method for energy source selection, is unique for the related problem in literature. The results of the proposed model from the case of Turkey will help practitioners and experts of how to apply it to the similar problems in the field of energy management.

Research limitations/implications

In short, in this paper, an integrated approach is proposed through the fuzzy AHP and the fuzzy GRA methods. As the fuzzy AHP is used to determine the weights of evaluation criteria, the fuzzy GRA is used to rank energy source alternatives.

Practical implications

In addition, a case study for Turkey is presented to show the applicability of the proposed approach for potential practitioners who are authority in the field of energy in public and private sectors.

Social implications

On the other hand, the proposed approach, the fuzzy AHP-GRA for energy source selection can also be an intelligent tool for public and private energy companies in Turkey, as well as others in the world.

Originality/value

On the other hand, in this paper, to the best of the authors’ knowledge, the study contributes to the literature that the first time, they use the fuzzy alpha-cut AHP and GRA in fuzzy environment for energy source evaluation problem.

Details

International Journal of Energy Sector Management, vol. 14 no. 1
Type: Research Article
ISSN: 1750-6220

Keywords

Article
Publication date: 1 September 1996

Nielen Stander and Erwin Stein

Using examples of flexible mechanisms, demonstrates that while the Newmark method is unstable for nonlinear dynamics, time step refinement could in some cases lead to even…

Abstract

Using examples of flexible mechanisms, demonstrates that while the Newmark method is unstable for nonlinear dynamics, time step refinement could in some cases lead to even earlier onset of instability in the form of a blown‐up response. As a remedy, develops a plane finite beam element based on the Simo‐Vu Quoc formulation for dynamics and integrates it with an energy‐conserving midpoint time‐stepping rule for solving problems in nonlinear dynamics. Shows that this combination produces a consistently stable and accurate dynamic analysis method even for large time steps.

Details

Engineering Computations, vol. 13 no. 6
Type: Research Article
ISSN: 0264-4401

Keywords

Open Access
Article
Publication date: 1 August 2018

Jiandong Chen, Yinyin Wu, Chong Xu, Malin Song and Xin Liu

Non-fossil fuels are receiving increasing attention within the context of addressing global climate challenges. Based on a review of non-fossil fuel consumption in major…

4368

Abstract

Purpose

Non-fossil fuels are receiving increasing attention within the context of addressing global climate challenges. Based on a review of non-fossil fuel consumption in major countries worldwide from 1985 to 2015, the purpose of this paper is to analyze trends for global non-fossil fuel consumption, share of fuel consumption and inequality.

Design/methodology/approach

The similarities were obtained between the logarithmic mean divisia index and the mean-rate-of-change index decomposition analysis methods, and a method was proposed for complete decomposition of the incremental Gini coefficient.

Findings

Empirical analysis showed that: global non-fossil fuel consumption accounts for a small share of the total energy consumption, but presents an increasing trend; the level of global non-fossil fuel consumption inequality is high but has gradually declined, which is mainly attributed to the concentration effect; inequality in global non-fossil fuel consumption is mainly due to the difference between nuclear power and hydropower consumption, but the contributions of nuclear power and hydropower to per capita non-fossil fuel consumption are declining; and population has the greatest influence on global non-fossil fuel consumption during the sampling period.

Originality/value

The main contribution of this study is its analysis of global non-fossil fuel consumption trends, disparities and driving factors. In addition, a general formula for complete index decomposition is proposed and the incremental Gini coefficient is wholly decomposed.

Details

Management Decision, vol. 57 no. 4
Type: Research Article
ISSN: 0025-1747

Keywords

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