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Enhancing aerodynamic performances of a high-turning compressor cascade via boundary layer suction

Science china(Technological Sciences) 2010年第10期53卷 2748-2755页

作者： GUO Shuang1, CHEN ShaoWen1, LU HuaWei2, SONG YanPing1 & CHEN Fu1 1 School of Energy Science and engineering, Harbin Institute of Technology, Harbin 150001, china 2 marine engineering college, dalian maritime university, dalian 116026, china School of Energy Science and engineering Harbin Institute of Technology Harbin China marine engineering college Dalian Maritime University Dalian China

Experimental investigation was carried out to study the effect of suction positions and suction flow rates on the aerodynamic performance of a compressor cascade with a large camber angle. The ink-trace flow visualization was conducted and the flow fields of the cascade were also measured. Three types of boundary layer suction configurations are compared,i.e. the suction surface suction,the endwall suction and the compound suction. Experimental results show that the large amount of suction flow rate gains more losses reduction than the small amount for a certain proper suction configuration,but the speed of loss decline slows down as the suction flow rate goes on increasing. Boundary layer suction on the suction surface obviously enhances the ability of the boundary layer around the midspan to withstand the negative pressure gradient of the flow passage. The range of the suction surface corner is also decreased. If the suction slot locates in the corner separation region where severe separation has happened,the flow separation will be terminated at the slot and redevelop downstream. And boundary layer suction on the endwall mainly influences the endwall corner region in remarkably delaying,lessening and reorganizing the corner separation. While the whole flow field is remarkably improved at both midspan and the corner region in the compound suction schemes. At higher suction flow rates,the aerodynamic performance of the compressor cascade is better than that with boundary layer suction simply on the suction surface or on the endwall. When the suction flow rate is 1.5% of the inlet mass flow,the compound suction scheme achieves a maximum loss reduction of 17% compared with the cascade without boundary layer suction.

关键词： boundary layer suction high-turning diffusion cascade suction flow rate suction position experimental investigation

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Rupture failure analysis of driving equipment frame of dredger

Rupture failure analysis of driving equipment frame of dredg...

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作者： LI Zheng~1 WEI Hai-jun~2 (1.School of engineering,The university of Queensland,Brisbane 4072,Australia 2.marine engineering college,dalian maritime university,dalian,116026,china)

The driving equipment of dredger,designed with frame as supporter,generally operates under a cyclic impact *** spiteof fact that the designed stress is much higher than operating stress by a safety factor,the rupture failure of frame occurred frequentlyfor numerous draggers.A study on failure has been conducted by means of metallograph and *** is shown that the ruptureis characteristic of fatigue as result of both the cyclic stress and *** to the effect of sea environment,the corrosion ariseson the steel plate of frame,and consequently produce a lot of corrosion pits on the surface when the antirust paint peels *** resultthe initiation of fatigue cracks was promoted in the corrosion pits,and finally bring about reducing of fatigue lifetime and rupture of frame.

关键词： Dredger Frame,Fatigue failure Corrosion

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Measurement and simulation of the two-phase velocity correlation in sudden-expansion gas-particle flows

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Acta Mechanica Sinica 2011年第4期27卷 494-501页

作者： Li-Xing Zhou.Yang Liu.Yi Xu Department of engineering Mechanics,Tsinghua university,100084 Beijing,china marine engineering college,dalian maritime university,116026 dalian,china Department of engineering Mechanics Tsinghua University Beijing China marine engineering college Dalian Maritime University Dalian China

In this paper the present authors measured the gas-particle two-phase velocity correlation in sudden expansion gas-particle flows with a phase Doppler particle anemometer （PDPA） and simulated the system behavior by using both a Reynolds-averaged Navier-Stokes （RANS） model and a large-eddy simulation （LES）. The results of the measurements yield the axial and radial time-averaged velocities as well as the fluctuation velocities of gas and three particle-size groups （30μm, 50μm, and 95μm） and the gasparticle velocity correlation for 30μm and 50μm particles. From the measurements, theoretical analysis, and simulation, it is found that the two-phase velocity correlation of sudden-expansion flows, like that of jet flows, is less than the gas and particle Reynolds stresses. What distinguishes the two-phase velocity correlations of sudden-expansion flow from those of jet and channel flows is the absence of a clear relationship between the two-phase velocity correlation and particle size in sudden-expansion flows. The measurements, theoretical analysis, and numerical simulation all lead to the above-stated conclusions. Quantitatively, the results of the LES are better than those of the RANS model.

关键词： PDPA measurement - Simulation Two-phasevelocity correlation Sudden expansion gas-particle flows

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Structure and photochromic properties of molybdenumphosphoric acid/TiO_2 composite films

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Science china Chemistry 2009年第2期52卷 169-173页

作者： QI He,LIU Yan,FENG Wei & ZHU YiMin college of Environmental Science and engineering,dalian maritime university,dalian 116026,china college of Environmental Science and engineering Dalian Maritime University Dalian China

TiO_2 sol-gel composite films with dropping molybdenumphosphoric acid(PMoA) have been prepared by sol-gel *** structure and constitute of composite thin films were studied with Fourier transforms infrared spectroscopy(FT-IR),atomic force microscopy(AFM),and X-ray diffraction(XRD) patterns,*** photochromic behavior and mechanism of composite thin films were inves-tigated with ultraviolet-visible spectra(UV-vis) and electron spin resonance(ESR).FT-IR results showed that the Keggin geometry of PMoA was still preserved inside PMoA/TiO2 composite thin films,and a charge transfer bridge was built at the interface of PMoA and TiO2 through the Mo-O-Ti *** topography of the composite film showed obvious changes before/after adding PMoA,and the surface topography of composite films showed obvious changes before/after irradiating as *** thin film had reversible photochromic *** with UV light,transparent films changed from colorless to blue and they can bleach completely with ambient air in the *** re-sults showed that TiO_2 were excitated by UV light to produce electrons,which deoxidized PMoA to produce *** photochromic process of PMoA/TiO_2 system was carried through elec-tron transfer mechanism.

关键词： molybdenumphosphoric acid TiO_2 composite film photochromism

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A New Navigation Strategy in Hypermedia Integral Ware Authoring System

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计算机工程 2002年第S1期28卷 141-144页

作者： FU Xianping1 , JIANG Jianping2(1. college of Computer Science and Technology, dalian maritime university, dalian 116026,china 2. college of Information engineering, dalian maritime university, dalian 116026,china ) college of Computer Science and Technology Dalian Maritime University Dalian 116026China college of Information engineering Dalian Maritime University Dalian 116026China

After analyzing the general navigation mechanisms and discussing the knowledge point card linking model which is the base of the navigation mechanism used in the Hypermedia Integral ware Authoring System(HIAS), the pa... 详细信息

关键词： Hypermedia Integral ware Navigation strategy

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DC dielectrophoresis separation of marine algae and particles in a microfluidic chip

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Science china Chemistry 2012年第4期55卷 524-530页

作者： SONG YongXin1, YANG JianDong1, SHI XiaoFei4, JIANG Hai3, WU YanBin1, PENG Ran1, WANG Qi5, GONG Ning2, PAN XinXiang1, SUN YeQing2 & LI DongQing1,31Department of marine engineering, dalian maritime university, dalian 116026, china 2Institute of Environmental Systems Biology, dalian maritime university, dalian 116026, china 3Department of Mechanical and Mechatronics engineering, university of Waterloo, Waterloo, ON, N2L 3G1, Canada 4college of Information Science and Technology, dalian maritime university, dalian 116026, china 5Department of Respiratory Medicine, the Second Hospital Affiliated to dalian Medical university, dalian 116026, china Department of marine engineering Dalian Maritime University Dalian China college of Information Science and Technology Dalian Maritime University Dalian China Department of Mechanical and Mechatronics engineering University of Waterloo Waterloo Canada Department of Respiratory Medicine the Second Hospital Affiliated to Dalian Medical University Dalian China Institute of Environmental Systems Biology Dalian Maritime University Dalian China

This paper reports a microfluidic method of continuous separation of marine algae and particles by DC dielectrophoresis. The locally non-uniform electric field is generated by an insulating PDMS triangle hurdle fabricated within a PDMS microchannel. Both the particles and algae are subject to negative DEP forces at the hurdle where the gradient of local electric-field strength is the strongest. The DEP force acting on the particle or the algae depends on particles' or algae's volume, shape and dielectric properties. Thus the moving particles and algae will be repelled to different streamlines when passing the hurdle. In this way, combined with the electroosmotic flow, continuous separation of algae of two different sizes, and continuous separation of polystyrene particles and algae with similar volume but different shape were achieved. This first demonstration of DC DEP separation of polystyrene particles and algae with similar sizes illustrates the great influence of dielectric properties on particle separation and potentials for sample pretreatment.

关键词： DC dielectrophoresis – marine algae – particle – microfluidic chip – permittivity difference

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Biological exposure models for oil spill impact analysis

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Journal of Environmental Sciences 2000年第4期12卷 482-485页

作者： XIONG De qi 1, Mark Reed 2, Narve Ekrol 2 (1. Department of marine Environmental engineering, dalian maritime university, dalian 116026, china E mail: deqi@*** 2. Department of Environmental engineering, SINTEF Applied Chemistry Institut 大连海事大学辽宁大连 1 1 6 0 2 SINTEF Applied Chemistry Institute 挪威 Trondheim 70 3 4

The oil spill impact analysis (OSIA) software system has been developed to supply a tool for comprehensive, quantitative environmental impact assessments resulting from oil spills. In the system, a biological component evaluates potential effects on exposed organisms based on results from a physico chemical fates component, including the extent and characteristics of the surface slick, and dissolved and total concentrations of hydrocarbons in the water column. The component includes a particle based exposure model for migratory adult fish populations, a particle based exposure model for spawning planktonic organisms (eggs and larvae), and an exposure model for wildlife species (sea birds or marine mammals). The exposure model for migratory adult fish populations simulates the migration behaviors of fish populations migrating to or staying in their feeding areas, over wintering areas or spawning areas, and determines the acute effects (mortality) and chronic accumulation (body burdens) from the dissolved contaminant. The exposure model for spawning planktonic organisms simulates the release of eggs and larvae, also as particles, from specific spawning areas during the spawning period, and determines their potential exposure to contaminants in the water or sediment. The exposure model for wild species calculates the exposure to surface oil of wildlife (bird and marine mammal) categories inhabiting the contaminated area. Compared with the earlier models in which all kinds of organisms are assumed evenly and randomly distributed, the updated biological exposure models can more realistically estimate potential effects on marine ecological system from oil spill pollution events.

关键词： oil spill biological exposure acute effects chronic accumulation migration of fish spawning of eggs and larvae habitat

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Fractal Characteristic of Pits Distribution on 304 Stainless Steel Corroded Surface and Its Application in Corrosion Diagnosis

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Journal of Wuhan university of Technology(Materials Science) 2007年第3期22卷 389-393页

作者：梁成浩 Electromechanics & Materials engineering college Dalian Maritime University

Electrochemical techniques and fractal theory were employed to study the corrosion behaviors and pits distribution characteristics on the corroded surfaces of 304 stainless steel exposed in FeCl3 solution. Fractal features of pits distribution over the corroded surfaces were observed and described by the fractal dimension. A 5-8-2 back-propagation （BP） artificial neural network model for the diagnoses of the pitting corrosion rate and pits deepness of 304 stainless steel under various conditions was developed by considering the fractal dimension as a key parameter for describing the pitting corrosion characteristics. The predicted results are well in agreement with the experimental data of pitting corrosion rate and pit deepness. The max relative errors between their experimental and simulation data are 6.69% and 4.62%, respectively.

关键词： 304 stainless steel pits distribution fractal neural network diagnosis

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A New Approach to Duffing Equation withStrong and High Order Nonlinearity

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Communications in Nonlinear Science and Numerical Simulation 1999年第2期4卷 132-135页

作者： Jianguo LIN(dalian maritime university, Institute of marine Environment, dalian 116024, china)E-mail: linjg@*** dalian maritime university Institute of Marine Environment Dalian 116024 China

A new parameter iteration technique is proposed to solve the Duffingequation with strong and high order nonlinearity. Contrary to the linearized perturbation technique parametrized perturbation technique and variational iteration techniqueproposed by J.H. He, the frequency converged asymptotically to the exact result, not aconstant.

关键词： nonlinear Duffing equation parameter iteration method

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A New Approximate Iteration Solution ofBlasius Equation

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Communications in Nonlinear Science and Numerical Simulation 1999年第2期4卷 91-94页

An approximate analytical solution of Blasius equation is obtained by theparameter iteration method. The comparison with Howarth’s numerical solution showsthat the accuracy of the proposed method is higher than other approximate analyticalsolutions. Further, we provide also a numerical iteration scheme which is simple, efficientand practical.

关键词： nonlinear problem parameter iteration method Blasius equation

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