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Forced Responses on a Radial Turbine with Nozzle Guide Vanes

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Journal of Thermal Science 2014年第2期23卷 138-144页

作者： liu yixiong YANG Ce MA Chaochen LAO DaZhong School of Mechanical Engineering Beijing Institute of Technology

Radial turbines with nozzle guide vanes are widely used in various size ***,due to the interferences with guide vanes,the blades of impellers are exposed to intense unsteady aerodynamic excitations,which cause blade vibrations and lead to high cycle failures(HCF).Moreover,the harmonic resonance in some frequency regions are unavoidable due to the wide operation *** to achieve a detail insight into vibration characteristics of radial flow turbine,a numerical method based on fluid structure interaction(FSI) is ***,the unsteady aerodynamic loads are determined by computational fluid dynamics(CFD).And the fluctuating pressures are transformed from time domain to frequency domain by fast Fourier-transform(FFT).Then,the entire rotor model is adopted to analyze frequencies and mode shapes considering mistuning in finite element(FE) ***,harmonic analyses,applying the pressure fluctuation from CFD,are conducted to investigate the impeller vibration behavior and blade forced response in frequency *** prediction of the vibration dynamic stress shows acceptable agreement to the blade actual damage in consistent tendency.

关键词： radial turbine forced response modal analysis harmonic resonance

Non-axisymmetric Flow Characteristics in Centrifugal Compressor

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Journal of Thermal Science 2015年第4期24卷 313-322页

作者： WANG Leilei LAO Dazhong liu yixiong YANG Ce School of Mechanical Engineering Beijing Institute of Technology College of Mechanical and Electrical Engineering Hebei University of Engineering

The flow field distribution in centrifugal compressor is significantly affected by the non-axisymmetric geometry structure of the *** experimental and numerical simulation methods were adopted in this work to study the compressor flow field distribution with different flow *** results show that the pressure distribution in volute is characterized by the circumferential non-uniform phenomenon and the pressure fluctuation on the high static pressure zone propagates reversely to upstream,which results in the non-axisymmetric flow inside the *** non-uniform level of pressure distribution in large flow condition is higher than that in small flow condition,its effect on the upstream flow field is also ***,the non-uniform circumferential pressure distribution in volute brings the non-axisymmetric flow at impeller *** different flow conditions,the circumferential variation of the absolute flow angle at impeller outlet is also ***,the non-axisymmetric flow characteristics in internal impeller can be also reflected by the distribution of the mass *** high static pressure region of the volute corresponds to the decrease of mass flow in upstream blade channel,while the low static pressure zone of the volute corresponds to the increase of the mass *** small flow condition,the mass flow difference in the blade channel is bigger than that in the large flow condition.

关键词： centrifugal impeller static pressure distortion non-axisymmetric flow mass flow blade loading

Investigation on Inlet Recirculation Characteristics of Double Suction Centrifugal Compressor with Unsymmetrical Inlet

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Journal of Thermal Science 2016年第4期25卷 312-324页

作者： YANG Ce WANG Yingjun LAO Dazhong TONG Ding WEI Longyu liu yixiong School of Mechanical Engineering Beijing Institute of Technology Beijing 100081 China School of Aerospace Engineering Beijing Institute of Technology Beijing 100081 China China North Engine Research Institute Tianjin 300405 China

The inlet recirculation characteristics of double suction centrifugal compressor with unsymmetrical inlet structures were studied in numerical method,mainly focused on three issues including the amounts and differences of the inlet recirculation in different working conditions,the circumferential non-uniform distributions of the inlet recirculation,the recirculation velocity distributions of the upstream slot of the rear *** results show that there are some differences between the recirculation of the front impeller and that of the rear impeller in whole working conditions..In design speed,the recirculation flow rate of the rear impeller is larger than that of the front impeller in the large flow range,but in the small flow range,the recirculation flow rate of the rear impeller is smaller than that of the front *** different working conditions,the recirculation velocity distributions of the front and rear impeller are non-uniform along the circumferential direction and their non-uniform extents are quite *** circumferential non-uniform extent of the recirculation velocity varies with the working conditions *** circumferential non-uniform extent of the recirculation velocity of front impeller and its distribution are determined by the static pressure distribution of the front impeller,but that of the rear impeller is decided by the coupling effects of the inlet flow distortion of the rear impeller,the circumferential unsymmetrical distribution of the upstream slot and the asymmetric structure of the *** the design flow and small flow conditions,the recirculation velocities at different circumferential positions of the mean line of the upstream slot cross-section of the rear impeller are quite different,and the recirculation velocities distribution forms at both sides of the mean line are *** recirculation velocity distributions in the cross-section of the upstream slot depend on the static pressure distributions in th

关键词： asymmetric intake double suction centrifugal compressor inlet recirculation recirculation flow circumferential distribution

Electrochemical co-reduction of holmium and magnesium ions in eutectic LiCl-KCl salts

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Rare Metals 2022年第4期41卷 1394-1402页

作者： Ji Wang Mei Li Wei Han Zhi-yixiong liu Xiao-Guang Yang Yang Sun Mi-Lin Zhang Key Laboratory of Superlight Materials and Surface Technology College of Material Science and Chemical EngineeringHarbin Engineering UniversityHarbin 150001China Institute of Nuclear Energy and Safety Harbin Engineering UniversityHarbin 150001China

The electrochemical co-reduction of Ho(Ⅲ)and Mg(Ⅱ)ions was investigated on Mo electrode in eutectic LiCl–KCl salts at temperature of 773 K using various electrochemical *** voltammogram(CV)and square wave voltammogram exhibit three reduction peaks corresponding to the reduction of Ho(Ⅲ)on pre-deposited Mg electrode,whose potentials are more positive than that of Ho on Mo electrode because of the formation of Mg-Ho intermetallic compounds by co-reduction of Ho(Ⅲ)and Mg(Ⅱ)***,chronopotentiometry and open-circuit chronopotentiometry were used to explore the electrochemical formation of Mg–Ho ***–Ho alloys were produced by galvanostatic electrolysis at the current of 1.5 A for different electrolysis ***_(5)Mg_(24),HoMg_(2) and HoMg intermetallic compounds were acquired and characterized by X-ray diffraction(XRD)and scanning electron microscopy(SEM)coupled with energy-dispersive spectroscopy(EDS).The results indicate that Mg–Ho intermetallic compounds,Ho_(5)Mg_(24),HoMg_(2) and HoMg,could be prepared by molten salts electrolysis.

关键词： Electrochemical formation Co-reduction MgHo alloys Galvanostatic electrolysis

Mathematical Model and Simulation of Cutting Force in Plunge Milling Process

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Transactions of Tianjin University 2007年第4期13卷 303-307页

作者：秦旭达赵剑波刘焕领张剑刚赵伟田颖 TOM O Muller NI Wangyang liu yixiong School of Mechanical Engineering Tianjin University Kennametal Inc. Latrobe

Plunge milling is a high-speed machining way and the cutter is fed in the direction of the Z axis, which is used to remove excess material rapidly in roughing operations. In this paper, the orthogonal cutting theory was used to study the plunge milling of LY12 alloy. A mathematic model for cutting force in plunge milling was established, and the milling process was simulated by using Matlab. It is found that the single tooth cutting experimental result is unstable because of unsymmetrical single tooth in the milling process, which leads to the difference between the simulation and experimental results. The trend of multiple teeth cutting experimental result is similar to that of the simulation result; however, the peak values in the experimental result are different, which is caused by the error of cutter’s position, and the error of peak value is less than 10%.

关键词： plunge milling cutting force aluminium alloys simulation

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风扇转子叶片防颤振设计技术

航空动力学报 2017年第7期32卷 1718-1727页

作者：杨琳张耀光刘一雄中国航空发动机集团有限公司沈阳发动机研究所压气机设计研究室沈阳110015 中国航空发动机集团有限公司沈阳发动机研究所强度设计研究室沈阳110015

以某两级风扇为对象开展防颤振设计技术研究。风扇转子叶片设计中,选择了合适的展弦比,既考虑到气动性能水平,还考虑到结构质量和颤振稳定性。采用流固耦合能量法评估所设计风扇的各排转子叶片的颤振稳定性问题,并通过叶片厚度、三维造... 详细信息

以某两级风扇为对象开展防颤振设计技术研究。风扇转子叶片设计中,选择了合适的展弦比,既考虑到气动性能水平,还考虑到结构质量和颤振稳定性。采用流固耦合能量法评估所设计风扇的各排转子叶片的颤振稳定性问题,并通过叶片厚度、三维造型、根尖弦长比等设计参数的调整消除颤振风险。研究结果表明:展弦比不应是方案设计阶段防颤设计唯一的关注参数;在叶尖跨声速的转速更容易发生颤振现象;较强的叶尖前缘激波会造成较强的流固耦合作用,形成复杂的气动功分布结构;叶片厚度和尖根弦长比等参数是改善叶片颤振风险的有效参数。

关键词：颤振风扇流固耦合激波展弦比

Development of a Detection Method for Assaying Calf Intestine Alkaline Phosphatase Activity

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Animal Husbandry and Feed Science 2015年第3期7卷 152-155,166页

作者： Lin Lin Lai Xiaofang Li Yi liu yixiong Lan Quanxue Lai Xintian Yang Guowu Shenzhen Academy of Metrology & Quality Inspection

[ Objective] This study was to develop a detection method for assaying calf intestine alkaline phasphatase activity in scientific research. [ Method ] By simulating the conditions and buffers for assaying calf intestine alkaline phosphatase used in the scientific research, the parameters influencing substmte concentration, reaction duration, eoloration time and buffer pH were optimized. [ Result] The activity of alkaline phosphatase detected varied hugely among different buffers, and potassium ferricyanide solution added with boracic acid achieved the stable coloration. The optimal water bath time was determined as 10 rain, and the substrate concentration was optimized as 0.04 moL/L. The increasing temperature did not have a large influence on low temperature enzymatic activity while did on high coneentration enzymatic activity. When the buffer pH was 7.0 - 8.0, the detection stability of alkaline phosphatase could be maintained well The ion intensity of buff- er had little effects on alkaline phasphatase activity. [ Conclusion] A detection method for assaying calf intestine alkaline phosphatase activity in scientific research was successfully developed in this study.

关键词： Alkaline phosphatase Calf intestine Activity detection Ultraviolet spectrophotomctry Scientific research

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风扇转子叶片防颤改进设计

航空动力学报 2020年第6期35卷 1296-1303页

作者：张耀光杨琳刘一雄中国航空发动机集团有限公司沈阳发动机研究所沈阳110015

通过能量法对某两级跨声风扇试验件原型方案进行气弹稳定性预测,对气弹不稳定转子几何造型进行修改以提高气弹稳定性。通过对原型和改型方案的几何造型、气动性能和振动特性以及气弹稳定性对比分析表明:改型方案最小模态气动阻尼比由-1... 详细信息

通过能量法对某两级跨声风扇试验件原型方案进行气弹稳定性预测,对气弹不稳定转子几何造型进行修改以提高气弹稳定性。通过对原型和改型方案的几何造型、气动性能和振动特性以及气弹稳定性对比分析表明:改型方案最小模态气动阻尼比由-1.46提升至1.83,消除了颤振风险,同时风扇气动性能保持不变且对原方案改动量较小。增加厚度、弦长使叶片相应径向位置的气弹稳定性增加,是改善颤振的有效手段,但是需要关注风扇气动性能变化。在相同槽道堵塞裕度降低量条件下,调整厚度分布提升气弹稳定性幅度最大。

关键词：风扇转子颤振能量法气动性能气弹稳定性

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一种氢燃料微尺度非预混燃烧室数值模拟

航空动力学报 2023年第11期38卷 2701-2710页

作者：莫妲尚守堂林宇震马宏宇刘一雄中国航发沈阳发动机研究所沈阳110015 北京航空航天大学航空发动机研究院北京100191

为降低航空发动机和地面燃机碳排放和NOx,提出一种多射流布局的氢燃料微尺度非预混燃烧室头部结构。为获得微尺度非预混燃烧组织机理,以及关键设计参数对燃烧性能的影响,采用k-ωSST(剪切应力输运)和FGM(火焰面生成流行)方法中的扩散火... 详细信息

为降低航空发动机和地面燃机碳排放和NOx,提出一种多射流布局的氢燃料微尺度非预混燃烧室头部结构。为获得微尺度非预混燃烧组织机理,以及关键设计参数对燃烧性能的影响,采用k-ωSST(剪切应力输运)和FGM(火焰面生成流行)方法中的扩散火焰方法,通过9种组分共26步反应开展数值仿真模拟,对动量通量比、当量比、空气和氢气的导流板高度进行敏感性分析,探究氢气与空气的混合特性、火焰结构、温度分布、NOx排放的影响因素。对比分析了传统航空煤油与氢气NOx排放。结果表明:减小动量通量比有利于缩短火焰长度,可降低169.6%的NOx;存在一个空气导流板高度的临界值,使得NOx最高,在15%含氧量条件下NOx的体积分数为5×10^(-6);氢气导流板高度由3 mm增加为11 mm,NOx减少75.9%。与传统煤油相比,最优结构参数组合方案可进一步降低85.7%的NOx。

关键词：氢燃料微尺度非预混 NOx 动量通量比导流板高度

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