Shanghai Key Laboratory of Mechanics in Energy and Environment Engineering

Qinzhou, China

Shanghai Key Laboratory of Mechanics in Energy and Environment Engineering

Qinzhou, China
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Lu H.,Shanghai University | Zhang J.,Shanghai University | Zhang J.,Shanghai Key Laboratory of Mechanics in Energy and Environment Engineering | Fan J.,Alfred University
Guti Lixue Xuebao/Acta Mechanica Solida Sinica | Year: 2011

The mechanical properties and tension deformation of the single-crystalline FCC Cu nanowires are simulated with different orientation under uniaxial tension. The yield and elastic modulus in three different orientations of <100>, <110> and <111> are investigated by the quasi-static classic MD (Molecular dynamics) based on an embedded-atom method potential at room temperature. It is found that nanowires have different mechanical properties when tensioned in different orientations. The yield stress of Cu nanowire is the highest in the <111> orientation, the second in the <100> orientation and the lowest in the <110> orientation; however, the ductility of Cu nanowire is the best in the <100> orientation, but poor in the <111> and <110> orientations. The effective young's moduli of Cu nanowire are markedly different in different crystallographic orientations, i.e. E<111> > E<110>>E<100>. Detailed discussion on the stress-strain relation and underlying deformation mechanism of the nanowires is given, paying more attention to the local dislocation structure evolution and the critical resolved shear stress.


Jiang J.,Shanghai institute of Applied Mathematics and Mechanics | Jiang J.,Shanghai Key Laboratory of Mechanics in Energy and Environment Engineering | Dong L.,Shanghai institute of Applied Mathematics and Mechanics | Dong L.,Shanghai Key Laboratory of Mechanics in Energy and Environment Engineering
Lixue Xuebao/Chinese Journal of Theoretical and Applied Mechanics | Year: 2012

The lane-changing rules are proposed on the basis of features of lane-changing behaviours in the two-sided type C weaving section. The multi-lane cellular automata model is adopted to investigate traffic flow in such a weaving section. The phase diagram is obtained by numerical simulation with different weaving lengths. It is shown that the weaving length has negligible effect on traffic states of the weaving section when traffic flows of both main road and on-ramp are free. However, the increase of weaving length can improve the traffic states of on-ramp when the traffic flow of main road or on-ramp is congested. Furthermore, the distributions of density, velocity and lane-changing frequency of vehicles are discussed in the case of free flow of main road and large on-ramp flux. It is found that lane-changing behaviours occur mainly on both merging and diverging areas and lead to local congestion correspondingly.


Luo D.,Shanghai University | Luo D.,Shanghai Key Laboratory of Mechanics in Energy and Environment Engineering | Huang D.,Shanghai University | Huang D.,Shanghai Key Laboratory of Mechanics in Energy and Environment Engineering | Wu G.,Nantong University
Journal of Renewable and Sustainable Energy | Year: 2011

Instead of using conventional horizontal axis wind turbine blades, a Magnus wind turbine is equipped with rotating cylinders, which rotate around their own axes according to the principle of the Magnus effect. Based on the blade element momentum (or BEM) theory, an analytical analysis of the Magnus wind turbine power performance is conducted and its expression of power coefficient has been derived in this paper. The analytical solution has shown that there is a close relationship between the power coefficient of Magnus wind turbine and its physical parameters such as the tip rotor solidity, the tip speed ratio of Magnus turbine, and the relative speed of the cylinders rotation. In addition, a numerical BEM computation for the power coefficient of Magnus wind turbine is also performed using experimental lift and drag coefficients of a rotating cylinder obtained in the previous literature in order to validate the analytical solution. As a result, the aerodynamic characteristics of Magnus wind turbine observed in this study will be of some guiding significance for the initial research and preliminary design of Magnus wind turbines. © 2011 American Institute of Physics.


Huang D.-G.,Shanghai University | Huang D.-G.,Shanghai Key Laboratory of Mechanics in Energy and Environment Engineering | Wu G.,Nantong University
Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering | Year: 2013

In this article, a new method is presented for simulation of incompressible flow field, which is called Newton iteration based on variational finite element method. Meanwhile, underlying theories and general steps in the solution procedure using this method have been described in detail. In order to validate this method, incompressible simulations on the flowfield around a circular cylinder were conducted. The achieved results were then compared with existing analytic solutions and good agreements have been obtained. In addition, the incompressible flow around an aerofoil was also calculated using both the proposed method and the conventional variational finite element method. It was found that the results obtained by the two methods were exactly the same; however, this proposed method can significantly improve the computational efficiency. © IMechE 2013.


Sun X.,Shanghai University | Sun X.,Shanghai Key Laboratory of Mechanics in Energy and Environment Engineering | Huang D.,University of Shanghai for Science and Technology
International Journal of Sustainable Energy | Year: 2014

Shanghai, known as the economic, financial and cultural centre of China, lies in the southern portion of the Yangtze River Basin and is the largest and most prosperous city in mainland China. With a high rate of economic and population growth, Shanghai's demand for energy continues to rise. However, Shanghai is a city with a lack of traditional energy resources, and relies heavily on steady supplies of fossil fuels imported from other regions of China. In order to ensure the optimal use of energy resources and limit the environmental impact, the Shanghai government has launched a new energy strategy and is committed to the development of renewable energy, especially wind power. This paper assesses the wind energy resource in Shanghai, reviews the current status of wind power utilisation, and identifies the major challenges facing the development of a robust wind energy industry in this fastest growing city of China. © 2013 © 2013 Taylor & Francis.


Sun X.,Shanghai University | Sun X.,Shanghai Key Laboratory of Mechanics in Energy and Environment Engineering | Huang D.,Shanghai University | Huang D.,Shanghai Key Laboratory of Mechanics in Energy and Environment Engineering | Wu G.,Nantong University
Energy | Year: 2012

Wind power has been the fastest growing form of renewable energy for the last few years. According to Intergovernmental Panel on Climate Change (IPCC) report, 80% of the world's energy supply could come from renewable sources by 2050 and wind energy will play a major role in electricity generation in 2050. In the growing market for wind energy and the limited available space onshore, the development of offshore wind farms become more and more important. With a rapid development of technology, the offshore wind power projects have become a trend in many countries like Europe now. Therefore, this paper aims to provide a brief overview of the current development status of offshore wind power in different countries and also explore the technical, economic and environmental issues around its development. Without doubt, offshore wind will lead technology advances in the wind sector in a near future as it seeks to exploit resources further offshore. © 2012 Elsevier Ltd.


Xu F.,Shanghai University | Lu D.Q.,Shanghai University | Lu D.Q.,Shanghai Key Laboratory of Mechanics in Energy and Environment Engineering
International Journal of Engineering Science | Year: 2010

The hydroelastic interaction between an incident gravity wave and a thin elastic plate floating on a two-layer fluid of finite depth is analyzed with the aid of the method of matched eigenfunction expansions. The fluid is assumed to be inviscid and incompressible. A two-dimensional problem is formulated within the framework of linear potential theory for small-amplitude waves. The fluid domain is divided into two and three regions for semi-infinite and finite plates, respectively, with the matching relations representing the continuities of the pressure and velocity. A new inner product involving two single integrals is proposed, in which the vertical eigenfunctions in the open water region of the two-layer fluid are orthogonal. Then the orthogonality of the eigenfunctions with respect to the newly defined inner product is used to obtain a set of simultaneous equations for the expansion coefficients of the velocity potentials, and the edge conditions are included as a part of the equation system. The effects of the fluid density ratio and the position of interface on the wave reflection and transmission are discussed. Numerical analysis shows that the method proposed herein is effective with a higher rate of convergence. © 2010 Elsevier Ltd. All rights reserved.


Zhang R.-L.,Shanghai University | Zhang R.-L.,Shanghai Key Laboratory of Mechanics in Energy and Environment Engineering | Di Q.-F.,Shanghai University | Di Q.-F.,Shanghai Key Laboratory of Mechanics in Energy and Environment Engineering | And 4 more authors.
Journal of Hydrodynamics | Year: 2010

The dynamics of two-phase flows with a constant driving force inside a micro-channel is studied by using the Lattice Boltzmann Method (LBM) and the Shan-Chen multiphase model in this article. Flow regimes under different wall wettabilities and over smooth and grooved geometric surfaces are investigated. It is found that flow behaviors are strongly affected by the wall wettability and topography. Our results show that the LBM is efficient and accurate, and has very good application prospect in the study of drag reduction of microscopic seepage of reservoir. © 2010 Publishing House for Journal of Hydrodynamics.


Gu C.,Shanghai University | Gu C.,Shanghai Key Laboratory of Mechanics in Energy and Environment Engineering | Di Q.,Shanghai University | Di Q.,Shanghai Key Laboratory of Mechanics in Energy and Environment Engineering | And 5 more authors.
Shiyou Kantan Yu Kaifa/Petroleum Exploration and Development | Year: 2011

Based on the analysis of the forces acting on a hydrophobic nanoparticle (HNP) in a reservoir microchannel, a model of the interacting energy was presented. The competition adsorption mechanism between HNPs and water molecules was investigated by the comparison of interacting energies on a HNP and on a water molecule from microchannel wall. The calculated results show that the combined force for the HNP is an attractive force toward the microchannel wall and the acting energy on the HNP from the wall is on the order of 10 -18 -10 -17J, which is about 10 3 times that on the water molecule. Thus the HNP can penetrate hydrated layer and can be absorbed on the microchannel wall. To validate the model, an experiment was conducted using scanning electron microscope (SEM) and Energy Disperse Spectroscopy (EDS) to investigate the adsorption of HNPs on the surface of the core which was treated with HNPs fluid. The results show that micro-and nano-structures of HNPs layer can be observed clearly on the core surface,which confirms that HNPs have broken through the hydrated layer and have formed an adsorption layer on the core surface.


Huang Y.X.,Shanghai University | Huang Y.X.,Shanghai Key Laboratory of Mechanics in Energy and Environment Engineering | Huang Y.X.,University of Lille Nord de France | Huang Y.X.,CNRS Laboratory of Oceanology and Geosciences | And 9 more authors.
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2011

In this paper we present an extended version of Hilbert-Huang transform, namely arbitrary-order Hilbert spectral analysis, to characterize the scale-invariant properties of a time series directly in an amplitude-frequency space. We first show numerically that due to a nonlinear distortion, traditional methods require high-order harmonic components to represent nonlinear processes, except for the Hilbert-based method. This will lead to an artificial energy flux from the low-frequency (large scale) to the high-frequency (small scale) part. Thus the power law, if it exists, is contaminated. We then compare the Hilbert method with structure functions (SF), detrended fluctuation analysis (DFA), and wavelet leader (WL) by analyzing fractional Brownian motion and synthesized multifractal time series. For the former simulation, we find that all methods provide comparable results. For the latter simulation, we perform simulations with an intermittent parameter μ=0.15. We find that the SF underestimates scaling exponent when q>3. The Hilbert method provides a slight underestimation when q>5. However, both DFA and WL overestimate the scaling exponents when q>5. It seems that Hilbert and DFA methods provide better singularity spectra than SF and WL. We finally apply all methods to a passive scalar (temperature) data obtained from a jet experiment with a Taylor's microscale Reynolds number Reλ 250. Due to the presence of strong ramp-cliff structures, the SF fails to detect the power law behavior. For the traditional method, the ramp-cliff structure causes a serious artificial energy flux from the low-frequency (large scale) to the high-frequency (small scale) part. Thus DFA and WL underestimate the scaling exponents. However, the Hilbert method provides scaling exponents ξθ(q) quite close to the one for longitudinal velocity, indicating a less intermittent passive scalar field than what was believed before. © 2011 American Physical Society.

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