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Controlling secondary flow in high-lift low-pressure turbine using boundary-layer slot suction

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Chinese Journal of Aeronautics 2024年第3期37卷 21-33页

作者： Xiao QU Liunan LI Yingjie zhang Xingen LU Junqiang ZHU yanfeng zhang School of Mechanical Engineering Beijing Institute of TechnologyBeijing 100081China Key Laboratory of Light-Duty Gas-Turbine Institute of Engineering ThermophysicsChinese Academy of SciencesBeijing 100190China School of Aeronautics and Astronautics University of Chinese Academy of SciencesBeijing 100190China

The design of high-lift Low-Pressure Turbines(LPTs)causes the separation of the boundary layer on the suction side of the blade and leads to a strong secondary *** present study aims to minimize secondary losses through endwall slot suction and incoming wakes in a front-loaded high-lift LPT cascade with Zweifel of 1.58 under low Reynolds number of *** slotted schemes for the boundary layer of the endwall were designed(Plan A and Plan B),and the effects of suction mass flow on secondary flow were *** underlying physics of the endwall boundary layer of the suction and secondary flow under unsteady wakes was *** results show that slot suction at the endwall boundary layer can significantly suppress the secondary flow by removing low-momentum *** A and B significantly reduced the secondary kinetic energy by 44.2%and 36.9%,respectively,compared with the baseline cascade at the suction mass flow ratios of 1%.With an increase in the mass flow ratio of suction,the secondary flow was gradually reduced in both Plans A and *** is more beneficial to control the secondary flow to destroy the intersection of the pressure side and suction side of the horseshoe vortex before it develops into a passage *** unsteady wakes,the combined effects of incoming wakes and endwall boundary layer suction can further suppress the secondary flow at the suction mass flow ratios of 2%for Plan A,because the positive and negative vorticity inside upstream wakes accelerated the mixing of the main flow and secondary flow and thus increased the energy of secondary vortices.

关键词： Low-pressure turbine Secondary flow Flow control Boundary-layer suction Incoming wake

Effects of Heat Transfer on Laminar-to-Turbulent Transition over a Compressor Blade Operating at Low Reynolds Number

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Journal of Thermal Science 2024年第5期33卷 1826-1838页

作者： LU Lehan WANG Mingyang zhang yanfeng SUN Shuang HUANG Zhen WANG Maomao Department of aviation Engineering Civil Aviation University of ChinaTianjin 300300China Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China State Key Laboratory of Aerodynamics CARDCMianyang 621000China

To control the transition process in a laminar separation bubble(LSB)over an ultra-high load compressor blade at a Re of 1.5×10^(5),the effects of wall heat transfer were considered and numerically investigated by large eddy simulations(LES).Compared with the adiabatic wall condition,the local kinematic viscosity of airflow was reduced by wall cooling;thus the effects of turbulent dissipation on the growth of fluctuations were *** such,the transition occurred much earlier,and the size of LSB became *** the cooled surface,the spanwise vortices deformed much more rapidly and the size of hairpin vortex structures was ***,the rolling-up of 3D hairpin vortices and the ejection and sweeping process very close to the blade surface was ***,the aerodynamic losses of the compressor blade were reduced by 18.2%and 38.4%for the two cooled wall *** results demonstrated the feasibility of wall cooling in controlling the transition within an LSB and reducing the aerodynamic loss of an ultra-highly loaded compressor blade.

关键词： heat transfer compressor blade laminar-to-turbulent transition loss generation

Research on the Icing Diagnosis ofWind Turbine Blades Based on FS–XGBoost–EWMA

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Energy Engineering 2024年第7期121卷 1739-1758页

作者： Jicai Guo Xiaowen Song Chang Liu yanfeng zhang Shijie Guo JianxinWu Chang Cai Qing’an Li College of Mechanical Engineering Inner Mongolia University of TechnologyHohhot010051China Inner Mongolia Key Laboratory of Special Service Intelligent Robotics Hohhot010051China Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing100190China

In winter,wind turbines are susceptible to blade icing,which results in a series of energy losses and safe operation ***,blade icing detection has become a top *** methods primarily rely on sensor monitoring,which is expensive and has limited ***-driven blade icing detection methods have become feasible with the development of artificial ***,the data-driven method is plagued by limited training samples and icing samples;therefore,this paper proposes an icing warning strategy based on the combination of feature selection(FS),eXtreme Gradient Boosting(XGBoost)algorithm,and exponentially weighted moving average(EWMA)*** the training phase,FS is performed using correlation analysis to eliminate redundant features,and the XGBoost algorithm is applied to learn the hidden effective information in supervisory control and data acquisition analysis(SCADA)data to build a normal behavior *** the online monitoring phase,an EWMA analysis is introduced to monitor the abnormal changes in features.A blade icing warning is issued when themonitored features continuously exceed the control limit,and the ambient temperature is below 0℃.This study uses data fromthree icing-affected wind turbines and one normally operating wind turbine for *** experimental results reveal that the strategy can promptly predict the icing trend among wind turbines and stably monitor the normally operating wind turbines.

关键词： Wind turbine blade icing feature selection XGBoost EWMA

Power-efficient programmable integrated multiport photonic interferometer in CMOS-compatible silicon nitride

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Photonics Research 2024年第3期12卷 I0011-I0020页

作者： SHUQING LIN yanfeng zhang ZHAOYANG WU SHIHAO ZENG QING GAO JIAQI LI XIAOQUN YU SIYUAN YU State Key Laboratory of Optoelectronic Materials and Technologies School of Electronics and Information TechnologySun Yat-sen UniversityGuangzhou 510275China Hefei National Laboratory Hefei 230088China

Silicon nitride(SiNx)is an appealing waveguide material choice for large-scale,high-performance photonic integrated circuits(PICs)due to its low optical ***,SiNx PICs require high electric power to realize optical reconfiguration via the weak thermo-optic effect,which limits their scalability in terms of device density and chip power *** report a 6-mode programmable interferometer PIC operating at the wavelength of 1550 nm on a CMOS-compatible low-temperature inductance coupled plasma chemical vapor deposition(ICP-CVD)silicon nitride *** employing suspended thermo-optic phase shifters,the PIC achieves 2×improvement in compactness and 10×enhancement in power efficiency compared to conventional *** 6-dimensional linear transformations are demonstrated including cyclic transformations and arbitrary unitary *** work demonstrates the feasibility of fabricating power-efficient large-scale reconfigurable PICs on the low-temperature ICP-CVD silicon nitride platform.

关键词： unitary arbitrary figuration

现象图析学视角下移动社交媒体用户数字囤积行为机理研究

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现代情报 2024年第7期44卷 3-12,73页

作者：张艳丰刘敏湘潭大学公共管理学院湖南湘潭411105

[目的/意义]探析移动社交媒体用户数字囤积行为的影响因素与生成机理,有助于丰富信息行为研究的理论范式,为深入解析移动社交媒体用户数字囤积行为现象提供理论指导与实践参考。[方法/过程]基于I-PACE理论模型框架,从“用户—情感—认... 详细信息

[目的/意义]探析移动社交媒体用户数字囤积行为的影响因素与生成机理,有助于丰富信息行为研究的理论范式,为深入解析移动社交媒体用户数字囤积行为现象提供理论指导与实践参考。[方法/过程]基于I-PACE理论模型框架,从“用户—情感—认知—行为”4个维度,对移动社交媒体用户数字囤积行为进行模型要素解析,并利用现象图析学质性方法深入挖掘该行为的内在机理,构建移动社交媒体用户数字囤积行为机理关系模型。[结果/结论]研究结果揭示了移动社交媒体用户数字囤积行为机理可分为注意触发、认知判断、感知控制、行为反馈4个子机理。

关键词：移动社交媒体数字囤积 I-PACE理论现象图析学生成机理

移动社交媒体用户数字囤积行为生成机理与引导策略研究

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情报资料工作 2024年第2期45卷 48-56页

作者：张艳丰刘敏湘潭大学公共管理学院湖南411105

[目的/意义]探析移动社交媒体用户数字囤积行为的结构要素与生成机理,有助于丰富信息行为研究的理论范式,为移动社交媒体用户数字囤积行为现象的解析提供理论与应用参考。[方法/过程]基于I-PACE理论模型框架,从“用户-情感-认知-行为”... 详细信息

[目的/意义]探析移动社交媒体用户数字囤积行为的结构要素与生成机理,有助于丰富信息行为研究的理论范式,为移动社交媒体用户数字囤积行为现象的解析提供理论与应用参考。[方法/过程]基于I-PACE理论模型框架,从“用户-情感-认知-行为”四个维度,对移动社交媒体用户数字囤积行为进行模型要素解析,构建移动社交媒体用户数字囤积行为机理关系模型。[结果/结论]提出移动社交媒体情境下用户数字囤积行为的具体引导策略,为有效破除数字信息时代下的囤积之困提供参考。

关键词：移动社交媒体数字囤积影响因素生成机理引导策略

现象图析学视角下在线健康信息替代搜寻行为机理研究

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情报理论与实践 2024年第7期47卷 107-114页

作者：张艳丰赵资澧湘潭大学公共管理学院湖南湘潭411105

[目的/意义]探析现象图析学视角下在线健康信息替代搜寻行为的影响因素与生成机理,有助于丰富信息行为研究的理论范式,为解决替代搜寻问题提供相应的建议与参考。[方法/过程]基于意义建构理论模型框架,从“情景—鸿沟—桥梁—结果”4个... 详细信息

[目的/意义]探析现象图析学视角下在线健康信息替代搜寻行为的影响因素与生成机理,有助于丰富信息行为研究的理论范式,为解决替代搜寻问题提供相应的建议与参考。[方法/过程]基于意义建构理论模型框架,从“情景—鸿沟—桥梁—结果”4个维度,对在线健康信息替代搜寻行为进行模型要素解析,并利用现象图析学质性方法深入挖掘该行为的内在机理,构建在线健康信息替代搜寻行为机理关系模型。[结果/结论]研究结果揭示了在线健康信息替代搜寻行为机理可分为情景触发、条件控制、桥梁构建、结果反馈4个子机理,并明晰了其机理关系,为今后相关研究者对在线健康信息替代搜寻行为机理研究提供理论借鉴和参考。

关键词：在线健康信息替代搜寻意义建构理论现象图析学生成机理

基于改进无模型自适应控制的漂浮式海上风机转矩-变桨协调控制策略研究

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动力工程学报 2024年第4期44卷 607-615页

作者：张艳峰杨锡运王忻哲华北电力大学控制与计算机工程学院北京102206

针对漂浮式海上风机建模困难、频繁变桨造成的严重疲劳损伤等问题,提出一种基于改进无模型自适应控制的转矩-变桨协调控制策略。该策略不依赖漂浮式海上风机的数学模型,通过集成迭代学习控制策略改进无模型自适应控制方法,设计发电机电... 详细信息

针对漂浮式海上风机建模困难、频繁变桨造成的严重疲劳损伤等问题,提出一种基于改进无模型自适应控制的转矩-变桨协调控制策略。该策略不依赖漂浮式海上风机的数学模型,通过集成迭代学习控制策略改进无模型自适应控制方法,设计发电机电磁转矩和桨距角作为控制变量的多输入多输出控制器进行协调控制,允许非零度桨距角下风机用做动能缓冲,在平滑输出功率的同时减少变桨动作量。为证明所提出控制策略的有效性,在多种风场景下,与增益调度PI控制等方法进行了对比实验。结果表明:所提出的控制策略使漂浮式海上风机在满足发电功率平稳性的同时减缓了漂浮平台的俯仰运动,可有效降低漂浮式海上风机的疲劳载荷。

关键词：海上风电漂浮式海上风机无模型自适应控制转矩-变桨协调控制

基于子空间域对抗判别网络的不同型号滚动轴承剩余寿命预测

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仪器仪表学报 2024年第3期45卷 119-127页

作者：陈仁祥张雁峰徐向阳张鹏博杨宝军重庆交通大学交通工程应用机器人重庆市工程试验室重庆400074 重庆智能机器人研究院重庆400714

针对不同型号滚动轴承因结构尺寸、运行工况等差异导致轴承退化数据分布和特征尺度不一致,引起剩余寿命预测精度下降的问题,提出基于子空间域对抗判别网络的不同型号滚动轴承剩余寿命预测方法。首先,通过高效通道注意力机制提升特征提... 详细信息

针对不同型号滚动轴承因结构尺寸、运行工况等差异导致轴承退化数据分布和特征尺度不一致,引起剩余寿命预测精度下降的问题,提出基于子空间域对抗判别网络的不同型号滚动轴承剩余寿命预测方法。首先,通过高效通道注意力机制提升特征提取器各通道中重要特征的权重,自适应获取不同型号滚动轴承的深层性能退化特征,并以此预训练标签预测器;然后,在对抗判别网络框架上将域判别器与特征提取器对抗训练,最小化源域和目标域在表征子空间上的正交基距离,利用表征子空间正交基不受特征缩放影响的性质克服特征尺度变化过大引起的回归性能下降问题,实现不同型号滚动轴承间的域自适应;最后,利用训练好的特征提取器提取待预测轴承退化特征,输入标签预测器得到剩余寿命。在PRONOSTIA、XJTU-SY和自测数据集上进行了验证,实验结果表明所提方法能充分学习源域特征分布信息,有效克服不同型号下的特征尺度差异,相比其他域自适应方法效果提升20%至40%。

关键词：滚动轴承剩余寿命预测对抗判别域自适应时间卷积网络