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Determination of the Circulation for a Large-Scale Wind Turbine Blade Using Computational Fluid Dynamics

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Fluid Dynamics & Materials Processing 2020年第4期16卷 685-698页

作者： hao Cheng Guangsheng Du meng Zhang Kun wang Wenbin Bai School of Energy and Power Engineering Shandong UniversityJinan250061China

The determination of the circulation for wind turbine blades is an important problem in *** the present study,we develop a specific approach to evaluate the integral that represents mathematically the *** the potentialities of the method are assessed using a two-dimensional NACA64_A17 airfoil as a testbed and evaluating the influence of different integration paths and angles of attack on the circulation *** the method is applied to blades with different relative heights in order to provide useful reference data to be used for the optimization and reverse design of wind turbine *** shown by the results,the integral value changes with the integral path,and an“optimal circle radius”*** calibrate the integral value by comparing its value with the lift *** this was we succeed in showing that there is a certain error when the radius is too ***,the error can increase rapidly when the radius is too *** the radius of the circle is 1–6 times the chord length,the error of all integral values is less than 5%.The optimal radius varies with the angle of attack.

关键词： Airfoil lift wind turbine circulation distribution

Highly safe and ionothermal synthesis of Ti3C2 MXene with expanded interlayer spacing for enhanced lithium storage

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Journal of Energy Chemistry 2020年第8期29卷 203-209,I0007页

作者： Junbiao Wu Yu wang Yaopeng Zhang hao meng Yan Xu Yide Han Zhuopeng wang Yanfeng Dong Xia Zhang Department of Chemistry College of SciencesNortheastern UniversityShenyang 110819LiaoningChina

MXene is a rising star of two-dimensional(2D)materials for energy relative applications,however,the traditional synthesis of MXene etched by hazard HF acid or LiF+HCl mixed solution is highly dangerous with the risk of splashing or pouring liquid *** this work,we developed a water-free ionothermal synthesis of 2D Ti3C2 MXene via etching pristine Ti3AlC2 MAX in low-cost choline chloride and oxalic acid based deep eutectic solvents(DES)with the presence of NH4F,thus it was highly safe and convenient to operate solid precursor and product materials at room *** from the low vapor pressure and solvating properties of DES,the prepared Ti3C2(denoted as DES-Ti3C2)possessed a high purity up to 98% compared with 95% for HF etched Ti3C2(denoted as HF-Ti3C2).Notably,an expanded interlayer spacing of 1.35 nm could be achieved due to the intercalation of choline cations in DES-Ti3C2,larger than that of HF-Ti3C2(0.98 nm).As a result,the DES-Ti3C2 anodes exhibited enhanced lithium storage performance,such as high reversible capacity of 208 m Ah g-1at 0.5 A g-1,and long cycle life over 400 times,outperforming most reported pure MXene *** ionothermal synthesis of MXene developed here may pave a new way to safely prepare other MXene for various energy relating applications.

关键词： Ionothermal synthesis Deep eutectic solvents MXene Expanded interlayer spacing Lithium ion batteries

Globularization Mechanism and Near Isotropic Properties in Subcritical Heat‑Treated Ti6Al4V Fabricated by Directed Energy Deposition

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Acta Metallurgica Sinica(English Letters) 2023年第6期36卷 937-948页

作者： Guohao Zhang Zhiwei hao meng wang Xufei Lu Zhuang Zhao Qian wang Xin Lin Jing Chen Weidong Huang State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China MIIT Key Laboratory of Metal High Performance Additive Manufacturing and Innovative Design Northwestern Polytechnical UniversityXi’an 710072China International Center for Numerical Methods in Engineering Universidad Politecnica de Cataluna08034 BarcelonaSpain Institute of Machinery Manufacturing Technology China Academy of Engineering PhysicsMianyang 621054China

Microstructure with globularαphase is desirable as it contributes to preferable comprehensive mechanical properties for titanium ***,titanium alloys fabricated by directed energy deposition(DED)are mainly characterized by the lamellarαphase within the basket-weave microstructure,which often leads to severe anisotropy and inferior low cycle fatigue(LCF)*** address this,the subcritical annealing and the cyclic annealing were applied to DED Ti–6Al–4V in order to achieve the transformation from the lamellarαphase to the globularα*** microstructural characteristics and the globularization behavior ofαphase during heat treatment were *** results show that the aspect ratio ofαis significantly decreased with the subcritical annealing due to the coarsening of lamellarα.Furthermore,the globularαis obtained with the cyclic annealing as a combination result of the termination dissolution and the side surface growth of the lamellarα.These contribute to a pronounced reduction of 85.4%in the ductility anisotropy,compared with the as-built specimens,and superior comprehensive mechanical properties including LCF are achieved with the formation of globularα.

关键词： Directed energy deposition Ti-6Al-4V Subcritical heat treatment Coarsening Globularization

Research on Two Types of Buffer Zone Impact on Surrounding Office Space Environment in Winter in Cold Climate Zone—a Fieldwork in Architectural Design Institute Building of Tsinghua University,Beijing

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Journal of Harbin Institute of Technology(New Series) 2014年第5期21卷 33-39页

作者： Ye-hao Song Jun-Jie Li Ning Zhu Jia-Liang wang Shi-meng hao School of Architecture Tsinghua University Key Laboratory of Eco Planning & Green Building Ministry of EducationTsinghua University

Building buffer zone space is not only one of essential approaches for better mental quality of interior building space, but also an important factor that may influence interior thermal comfort and energy consumption. This study aims to analyze regulative advantages of buffer zone to the surrounding functional spaces. Based on a fieldwork test in a typical office building in cold climate zone in Beijing,China,the monitor data show interior physical performance in the Winter. The research selects two types of different buffer zones in the same building. One is a south-faced greenhouse which has large dimension with plenty of vegetation,and the other is a simple atrium in the middle of five floor building with mount of skylights. The factors and their influence to surrounding functional spaces and the whole building are found out from the comparisons of collected data by floor to floor monitor test on both buffer zones at the same time. The comparisons of two types of buffer zones conclude that the greenhouse is more effective to air quality regulation but not so clearly wellperformed to thermal buffering as expected due to the dominate active central heating in the Winter. This fieldwork test results for building performance can be helpful for both architects and engineers in the early phase of sustainable design.

关键词： public building buffer zone building performance fieldwork test space effect

Property evolution and service life prediction of novel metallic materials for future lunar bases

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Rare Metals 2024年第10期43卷 5318-5331页

作者： Sen-Kuan meng Rui-Song Zhu Hong-Liang Zheng Tong Gao Shi-hao Jiang Wen-hao wang Shu-hao Zhang Zi-Yuan Zhao Xuan Ge Wei-Min wang Li-Na Hu Zheng wang Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials(Ministry of Education) School of Materials Science and EngineeringShandong UniversityJinan 250061China Department of Chemistry and Bioscience Aalborg University9220AalborgDenmark

While lunar bases have been a focus of development in recent years,the complex and extreme environment of the lunar surface remains a considerable challenge for lunar *** those on Earth,lunar day and night temperature variations cause the properties of materials,especially metallic materials,to evolve in completely different *** this study,we investigated the property evolution of nine typical highperformance metallic materials using laboratory simulations of the extremely long-period lunar temperature *** lunation treatment improves the properties of all metallic materials,the microscopic mechanisms vary for amorphous and crystalline alloys with different *** treatment reduces both the loosely packed regions and heterogeneity in amorphous alloys while causing significant phase changes in crystalline ***,a conservative prediction of the service life of metallic materials on lunar bases is provided based on analyzing microplastic events,followed by the practical material selection recommendations in various lunar application scenarios.

关键词： Metallic glass Property evolution Lunar exploration Metallic material

Theoretical and experimental investigation on novel 2D maglev servo proportional valve

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Chinese Journal of Aeronautics 2021年第4期34卷 416-431页

作者： Bin meng hao XU Jian RUAN Sheng LI Key Laboratory of Special Purpose Equipment and Advanced Manufacturing Technology Ministry of Education Zhejiang University of TechnologyHangzhou 310018China

This paper presents a novel two-dimensional maglev servo proportional cartridge valve(2 D maglev valve),where a contactless maglev coupling is introduced between electro-mechanical converter and valve body to realize functions of force transmission,spool position feedback and linear-rotary motion *** configuration can effectively reduce cost of both valve manufacturing and electro-mechanical converter,while still maintain features of 2 D valve such as null pilot leakage,high power-to-weight ratio and excellent anti-pollution ***,the characteristic equation of the valve is derived using linear theory,and the stability criterion is established for parameter *** influences of crucial structural parameters such as initial height of overlapping area,width of high-pressure and low-pressure holes,acting radius of magnetic force,pitch angle of maglev coupling,length of sensitive chamber and system pressure on the dynamic response are investigated based on AMESim numerical *** prototype valve is then designed and manufactured and a special test rig is *** no-load flow characteristic,load flow characteristic,leakage characteristic,amplitude and phase frequency characteristics and step response under different system pressures are *** experimental results are in a good agreement with the simulated *** an over-damped system,the prototype valve has excellent working stability,which can reach a no-load flow rate of 105.9 L/min with hysteresis of 3.51%,amplitude bandwidth of 28.7 Hz and phase bandwidth of 42.8 Hz under 21 *** research indicates that the 2 D maglev valve can be a potential solution of flow rate control valve for flight control surface system of civil aircraft with high pressure and large flow rate application.

关键词： Dynamic characteristic 2D valve Maglev coupling Servo proportional valve Stability criterion

Nonlinear Dynamic Characteristics of Turbulent Non-Premixed Acoustically Perturbed Swirling Flames

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Journal of Thermal Science 2022年第3期31卷 882-894页

作者： ZHOU hao TAO Chengfei meng Sheng CEN Kefa State Key Laboratory of Clean Energy Utilization Zhejiang UniversityHangzhou310027China

The main objective of this article was to experimentally investigate the dynamic response of diffusion flame under acoustic excitation in a laboratory-scale *** parametric variations of the burner,the burner inlet length and variation of the airflow rate,were *** results were analyzed through nonlinear time series analysis and several resonance characteristics were *** indicate that the flame-acoustic resonance only appears under certain frequencies together with the fuel tube *** characteristics of the combustion chamber and air inlet in the non-premixed burner indicate quasi-periodic or limit cycle oscillations,***-acoustic resonance would trigger the frequency and amplitude mode-transition in ***,the intermittency of flame heat release was observed under variation of inlet length and airflow rate in the burner;the 445 mm case shows more frequency peaks and fluctuations than the 245 mm *** typical flame forms were examined during the flame-acoustic resonance conditions,evolves from wrinkled flames to diverged flames,then evolves to reattached flames and finally to blow-off *** study proposed the practical application of nonlinear time-series analysis method as a detection tool for flame-acoustic resonance in laboratory non-premixed burners,which could contribute to the detection and prevention of potential thermoacoustic instabilities or resonance structure failures of industrial ***,this study demonstrates an alternative to conventional linear tool for the characterization of nonlinear acoustic resonance in industrial boilers.

关键词： flame-acoustic resonance non-linear time series analysis non-premixed burners intermittency dynamic characteristics

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蜗舌改型设计对多翼离心风机气动性能的影响

风机技术 2018年第6期60卷 31-37页

作者：熊仲营邓稼琦王梦豪杨罗娜孙利校西安交通大学能源与动力工程学院西安市八十九中学杭州德意电器股份有限公司

蜗舌作为多翼离心风机蜗壳的重要组成部分对风机的气动性能和噪声有着重要的影响。本文针对吸油烟机用多翼离心风机蜗舌进行了改型设计,获得了一种新型的圆弧蜗舌结构。采用数值计算方法对原型风机和带有新型圆弧蜗舌的风机流场特性和... 详细信息

蜗舌作为多翼离心风机蜗壳的重要组成部分对风机的气动性能和噪声有着重要的影响。本文针对吸油烟机用多翼离心风机蜗舌进行了改型设计,获得了一种新型的圆弧蜗舌结构。采用数值计算方法对原型风机和带有新型圆弧蜗舌的风机流场特性和气动噪声进行了对比分析。基于实验测量,验证了多翼离心风机气动性能数值模拟结果的有效性。研究结果表明:圆弧蜗舌的采用,降低了多翼离心风机出口气流对蜗舌的冲击,减小了蜗舌处气流的压力梯度及旋涡强度,增加了风机出口处的有效通流面积,抑制了蜗舌区域噪声的迭加,从而有效降低了多翼离心风机的气动噪声。相比较于原型风机,圆弧蜗舌的采用使得风机在风量提高0.53m3/min,总压增加15Pa的情况下,噪声下降了0.7dB。

关键词：多翼离心风机蜗舌气动性能噪声数值仿真

High Q,high frequency,high overtone bulk acoustic resonator with ZnO films

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Journal of Zhejiang University-Science C(Computers and Electronics) 2013年第4期14卷 279-282页

作者： meng-wei LIU Ming-bo ZHU Jun-hong LI Cheng-hao wang State Key Laboratory of Acoustics Institute of AcousticsChinese Academy of Sciences

Bulk acoustic wave resonators with piezoelectric films have been widely explored for the small size and high quality factor （Q） at GHz. This paper describes a high overtone bulk acoustic resonator （HBAR） based on AI/ZnO/AI sandwich layers and c-axis sapphire substrate. ZnO film with high quality c-axis orientation has been obtained using DC magnetron sputtering. The fabricated HBAR presents high Q at the multiple resonances from a 0.5-4.0 GHz wide band with a total size （including the contact pads） of 0.6 mm×0.3 mm×0.4 mm, The device exhibits the best acoustic coupling at around 2.4 GHz, which agrees with the simulation results based on the one-dimensional Mason equivalent circuit model. The HBAR also demonstrates Q values of 30 000, 25 000, and 6500 at 1.49, 2.43, and 3.40 GHz, respectively. It is indicated that the HBAR has potential applications for the low phase noise high frequency oscillator or microwave signal source.

关键词： Bulk acoustic wave resonator Quality factor (Q) ZnO film Mason's model