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Rare Metals 2017年第6期36卷 501-511页

作者： Somasundaram Praveen Kumar Kathiresan Sakthipandi Ramamurthy Gayathiri Mathu Sridhar Panday Arumugam Karthik Venkatachalam Rajendran centre for Nano Science and technology K.S. Rangasamy College of Technology Anna University research and development centre Bharathiar University

Series of bulk and nanostructured La0.7SrxCa0.3-xMnO3（x = 0.10, 0.15, and 0.20） manganites were synthesized and characterized using different techniques. In the series, both the bulk and nanostructured La0.7Sr0.10Ca0.20MnO3 and La0.7Sr0.20Ca0.10MnO3 manganites have orthorhombic and rhombohedral structures, whereas La0.7Sr0.15Ca0.15MnO3 manganite has rhombohedral and orthorhombic structures, respectively. Online ultrasonic velocity and attenuation measurements were taken through an indigenously designed ultrasonic setup, and the analysis was done from 300 to 400 K during the aging of the samples to explore the structural/phase transitions. The bulk and nanocrystalline La0.7SrxCa0.3-xMnO3 perovskite samples show the particle size distribution in the range of 197-943 and 24-93 nm, respectively. The addition of Sr^2＋ alters the size of particles, which decrease in size. The observed anomaly in ultrasonic velocities, attenuations, and elastic moduli is correlated with the ferromagnetic-paramagnetic（FM-PM） transition temperature（TC） in both bulk and nanocrystalline perovskites. In addition, the shift in TC and the magnitude and width of observed anomaly are correlated with the value of x to study the behavior of TC.

关键词： Magnetic material Ultrasonic measurements Elastic properties Phase transition

Fatigue Assessment Method for Composite Wind Turbine Blade

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Transactions of Nanjing University of Aeronautics and Astronautics 2016年第1期33卷 102-111页

作者： Chen Cheng Wang Tongguang Jiangsu Key Laboratory of hi-tech research for Wind Turbine Design Nanjing University of Aeronautics and Astronautics

Fatigue strength assessment of a horizontal axis wind turbine(HAWT)composite blade is *** load cases are identified,and loads are calculated by the GH Bladed software which is specified at the IEC61400 international specification and GL(Germanisher Lloyd)regulations for the wind energy conversion *** analysis is performed with a 3-D finite element method(FEM).Considering Saint-Venant′s principle,a uniform cross section FEM model is built at each critical *** transformation matrixes(STM)are set up by applied six unit load components on the FEM model *** can be used to convert the external load into stresses in the linear elastic *** main material of composite wind turbine blade is fiber reinforced plastics(FRP).In order to evaluate the degree of fatigue damage of FRP,the stresses of fiber direction are extracted and the well-known strength criterion-Puck theory is *** total fatigue damage of each laminate on the critical point is counted by the rain-flow counting method and Miner′s damage law based on general S-N *** sections of a 45.3mblade of a 2 MW wind turbine are studied using the fatigue evaluation *** performance of this method is compared with far more costly business software *** results show that the fatigue damage of multi-axis FRP can be assessed conveniently by the FEM-STM *** the proposed method gives a reliable and efficient method to analyze the fatigue damage of slender composite structure with variable cross-sections.

关键词： fatigue assessment wind turbine blade finite element method(FEM) stress transformation matrix

Aeroelastic Responses for Wind Turbine Blade Considering Bend-Twist Coupled Effect

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Transactions of Nanjing University of Aeronautics and Astronautics 2016年第1期33卷 16-25页

作者： Li Yijin Wang Tongguang Jiangsu Key Laboratory of hi-tech research for Wind Turbine Design Nanjing University of Aeronautics and Astronautics

The Euler-Bernoulli beam model coupled with the sectional properties obtained by the variational asymptotic beam sectional analysis(VABS)method is used to construct the blade structure *** the aerodynamic loads calculated by unsteady blade element momentum model with a dynamic inflow and the dynamic stall correction,the dynamics equations of blade are *** Newmark implicit algorithm is used to solve the dynamics *** of the sectional properties and blade structure model are compared with the multi-cell beam method and the ANSYS using shell *** is proved that the method is effective with high ***,the effects on the aeroelastic response caused by bend-twist coupling are *** direction is deflected toward the upwind direction as a result of coupling *** aerodynamic loads and the displacement are reduced.

关键词： variational asymptotic beam sectional analysis (VABS) wind turbine unsteady blade element momen turn theory dynamic stall aeroelastic responses

Correction Model for Stall Delay on Rotating Blades

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Transactions of Nanjing University of Aeronautics and Astronautics 2016年第1期33卷 60-66页

作者： Zhong Wei Wang Tongguang Jiangsu Key Laboratory of hi-tech research for Wind Turbine Design Nanjing University of Aeronautics and Astronautics

Stall delay is an important phenomenon on wind turbine *** makes the maximum aerodynamic load of a rotating blade much higher than the one predicted without a correction.A new stall delay model is established here based on the investigation of the flow around a rotating *** investigation results indicate that the shrink of separation vortex caused by centrifugal force is the major reason for the stall *** factors related to the rotational effects are considered in the proposed model,such as rotating speed,inflow velocity,local chord length and radial ***,the model are validated on the NREL PhaseⅣ blade and the results demonstrate that the accuracy of the aerodynamic prediction for the blade is significantly improved as the model is applied.

关键词： wind turbine rotational effects stall delay computational fluid dynamics(CFD)

Large-Eddy Simulation of Wind Turbine Wake and Aerodynamic Performance with Actuator Line Method

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Transactions of Nanjing University of Aeronautics and Astronautics 2016年第1期33卷 26-36页

作者： Qian Yaoru Wang Tongguang Jiangsu Key Laboratory of hi-tech research for Wind Turbine Design Nanjing University of Aeronautics & Astronautics

A hybrid method is presented to numerically investigate the wind turbine aerodynamic *** wind turbine blade is replaced by an actuator line *** is treated using a dynamic one-equation subgrid-scale model in large eddy *** information on the basic characteristics of the wind turbine wake is obtained and *** rotor aerodynamic performance agrees well with the *** actuator line method large-eddy simulation(ALM-LES)technique demonstrates its high potential in providing accurate load prediction and high resolution of turbulent fluctuations in the wind turbine wakes and the interactions within a feasible cost.

关键词： actuator line large-eddy simulation(LES) wind turbine wake

Modeling three-dimensional dynamic stall

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Applied Mathematics and Mechanics(English Edition) 2011年第4期32卷 393-400页

作者：吕超王同光 Jiangsu Key Laboratory of hi-tech research for Wind Turbine Design Nanjing University of Aeronautics and Astronautics

The dynamic stall process in three-dimensional （3D） cases on a rectangular wing undergoing a constant rate ramp-up motion is introduced to provide a qualitative analysis about the onset and development of the stall phenomenon. Based on the enhanced understanding of the mechanism of dynamic stalls, a 3D dynamic stall model is constructed with the emphasis of the onset, the growth, and the convection of the dynamic stall vortex on the 3D wing surface. The results show that this engineering dynamic stall model can simulate the 3D unsteady aerodynamic performance appropriately.

关键词： unsteady flow 3D dynamic stall separation flow vortex motion

Wake Numerical Simulation of Wind Field Based on Two Modified Wind Engineering Models

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Transactions of Nanjing University of Aeronautics and Astronautics 2016年第1期33卷 53-59页

作者： Yang Xiangsheng Zhao Ning Tian Linlin Jiangsu Key Laboratory of hi-tech research for Wind Turbine Design Nanjing University of Aeronautics & Astronautics

With the assumption of the Park model that the wake region is in linear expansion and the cross-wind is in multinomial and Gaussian distribution in wake region,one develops the Park-polynomial model and the ParkGaussian model to numerically simulate the wake flow field for a single wind *** with the measured data of wind farm and the wind tunnel test,it shows that the prediction precision of wake field has been improved obviously under the modified initial wake ***,both of the newly modified two models could well simulate the wind velocity in wake region,because the predicted results is approximately consistent with the test result,and the cross-wind distribution conforms to that of the real flow *** two models have still inherited many advantages of engineering models,such as simple form,easy-to-code,and high computational ***,the Park-Gaussian model is the best in overall performance among them.

关键词： Park-polynomial model Park-Gaussian model wind turbine wake

Modeling Methods and Test Verification of Root Insert Contact Interface for Wind Turbine Blade

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Transactions of Nanjing University of Aeronautics and Astronautics 2016年第1期33卷 9-15页

作者： Li Hui Wang Tongguang Jiangsu Key Laboratory of hi-tech research for Wind Turbine Design Nanjing University of Aeronautics and Astronautics

Two modeling methods of the root insert for wind turbine blade are presented,i.e.,the local mesh optimization method(LMOM)and the global modeling method(GMM).Based on the optimized mesh of the local model for the metal contact interface,LMOM is proposed to analyze the load path and stress distribution characteristics,while GMM is used to calculate and analyze the stress distribution characteristics of the resin layer established between the bushing and composite layers of root *** validate the GMM,a tension test is carried *** result successfully shows that the shear strain expresses a similar strain distribution tendency with the GMM′s results.

关键词： root insert modeling methods mesh optimization contact interface tension test

Effect of B and Fe substitution on structure of AB_3-type Co-free hydrogen storage alloy

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Transactions of Nonferrous Metals Society of China 2010年第10期20卷 1885-1891页

作者：吴锋张旻昱穆道斌 Beijing Key Laboratory of Environmental Science and Engineering School of Chemical Engineering and EnvironmentBeijing Institute of Technology National development Center of hi-tech Green Materials

A series of hydrogen storage Co-free AB3-type alloys were directly synthesized with vacuum mid-frequency melting method,within which Ni of La0.7Mg0.3Ni3 alloy was substituted by Fe,B and(FeB) alloy,*** were characterized by XRD,EDS and SEM to investigate the effects of B and Fe substitution for Ni on material *** content of LaMg2Ni9 phase within La0.7Mg0.3Ni3 alloy reaches 37.9% and that of La0.7Mg0.3Ni2.9(FeB)0.1 alloys reduces to 23.58%.Among all samples,ground particles with different shapes correspond to different *** major substitution occurs in LaMg2Ni9 *** tests indicate that substituted alloys have different electrochemical performance,which is affected by phase structures of *** discharge capacity of La0.7Mg0.3Ni3 alloy reaches 337.3 mA·h/g,but La0.7Mg0.3Ni2.9(FeB)0.1 alloy gets better high rate discharge(HRD) performance at the discharge rate of 500 mA/g with a high HRD value of 73.19%.

关键词： Ni-MH battery AB3-type B substitution Co-free hydrogen storage alloy

Genetic diversity and population structure of Leptosphaeria maculans isolates in Western Canada

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Journal of Genetics and Genomics 2021年第11期48卷 994-1006页

作者： Qilin Chen Gary Peng Randy Kutcher Fengqun Yu Saskatoon research and development centre Agriculture and Agri-Food CanadaSaskatoonCanada Department of Plant Sciences Crop Development CentreUniversity of SKSaskatoonSKCanada

Leptosphaeria maculans is a serious concern for canola production *** effective disease management,knowledge of the pathogen’s genetic variability and population structure is a *** this study,whole-genome sequencing was performed for 162 of 1590 *** isolates collected in the years 2007e2008 and 2012e2014 in Western *** variants in genome-wide and specific regions including avirulence(Avr)genes were characterized.A total of 31,870 high-quality polymorphic DNA variants were used to study *** genetic diversity and population *** analysis showed that 150 isolates were clustered into 2 main groups and 4 subgroups by DNA variants located in either Avr or small secreted protein-encoding genes and into 2 main groups and 6 subgroups by genome-wide *** analysis of nucleotide diversity and differentiation also confirmed genetic variation within a population and among *** component analysis with genome-wide variants showed that the isolates collected in 2012e2014 were more genetically diverse than those collected in *** structure analysis discovered three distinct *** isolates from Saskatchewan and Alberta were of similar genetic composition,Manitoba isolates were highly ***-wide association study detected DNA variants in genes AvrLm4-7,Lema_T86300,and Lema_T86310 associated with the years of collection.

关键词： Leptosphaeria maculans DNA variants Blackleg Genetic diversity Population structure