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Experimental investigation on the flow structure over a simplified Papilio Ulysses model

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Chinese Science Bulletin 2009年第6期54卷 1026-1031页

作者： HU Ye WANG JinJun zhang panfeng zhang Cao Fluid Mechanics Institute Beijing University of Aeronautics and Astronautics Beijing 100191 China Corresponding author (email: jjwang@***)

The aerodynamic characteristics of butterflies, especially those which can migrate overseas, have received a great deal of attention because they have larger-scale wingspans and lower flapping frequencies than other insects such as drosophilae and bees. The objective of this work is to investi-gate the flow structures over a simplified model of Papilio Ulysses, one kind of migratory butterflies, through hydrogen bubble visualizations, and leading-edge vortices, wing-tip vortices, separation bub-bles and horseshoe vortex wake are observed. Moreover, the variations of these structures with the angle of attack are discussed in detail. A new type of leading-edge vortices which resembles the inversed Chinese character "八" is observed in the experiment.

关键词：流场结构凤蝶模型实验空气动力特性流动结构可视化马蹄涡

Extreme Temperature Change of the Last 110 Years in Changchun,Northeast China

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Advances in Atmospheric Sciences 2020年第4期37卷 347-358,I0002-I0006页

作者： Xiujing YU Guoyu REN panfeng zhang Jingbiao HU Ning LIU Jianping LI Chenchen zhang Jilin Climate Center Changchun 130062China Department of Atmospheric Science School of Environmental StudiesChina University of GeosciencesWuhan 430074China Laboratory for Climate Studies National Climate CenterChina Meteorological AdministrationBeijing 100081China Jilin Province Weather Modification Office Changchun 130062China Institute of Meteorological Sciences of Jilin Province Changchun 130062China

In China and East Asia,the long-term continuous observational data at daily resolution are insufficient,and thus there is a lack of good understanding of the extreme climate variation over the last 100 years *** this study,the extreme temperature indices defined by ETCCDI(Expert Team on Climate Change Detection and Indices)and local meteorological administrations were analyzed for Changchun City,Northeast China,by using the daily maximum temperature(Tmax)and daily minimum temperature(Tmin)over 1909?*** results showed that extreme cold events,such as cold days,cold nights,frost days,icing days,and low temperature days,decreased significantly at rates of?0.41 d(10 yr)^?1,?1.45 d(10 yr)^?1,?2.28 d(10 yr)^?1,?1.16 d(10 yr)?1 and?1.90 d(10 yr)^?1,*** nights increased significantly at a rate of 1.71 d(10 yr)^?1,but warm days decreased slightly and the number of high temperature days decreased at a rate of?0.20 d(10 yr)?*** frequency of cold surge events increased significantly at a rate of 0.25 d(10 yr)^?1,occurring mainly from the mid-1950s to *** average Tmax,average Tmin and extreme Tmin increased at rates of 0.09℃(10 yr)^?1,0.36℃(10 yr)^?1 and 0.54℃(10 yr)^?1,respectively;and extreme Tmax decreased significantly at a rate of?0.17℃(10 yr)^?*** 1909?2018,1951?2018 and 1979?2018,the indices related to cold events decreased,while the trends of the indices related to warm events were different for different periods.

关键词： extreme temperature climate change long-term series observation Changchun Northeast China

Lift enhancement method by synthetic jet circulation control

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Science China(Technological Sciences) 2012年第9期55卷 2585-2592页

作者： zhang panfeng YAN Bo DAI ChenFeng State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghai 200240China Institute of Fluid Mechanics Beijing University of Aeronautic and AstronauticsBeijing 100191China Key Laboratory of Fluid Mechanics Ministry of EducationBeijing 100191China

A novel circulation control technique is proposed to overcome the shortcomings of blowing jet circulation control, which uses the synthetic jet as the actuator and avoids the limitation about air supply requirement. The effectiveness of synthetic jet circulation control to enhance lift of NCCR1510-7067N airfoil is confirmed by solving the 2-D unsteady Reynolds-averaged Na- vier-Stokes equations. The aerodynamic characteristics and the flow structure （especially close to the trailing edge） of NCCR 1510-7067N airfoil at zero angle of attack are also presented to discuss the mechanism of lift enhancement of the airfoil with synthetic jet circulation control. The results indicate that the synthetic jet can effectively delay the separation point on the airfoil trailing edge and increase the circulation and lift of the airfoil by Coanda effect. The numerical simulation results demonstrate that the lift augmentation efficiency with synthetic jet circulation control reaches △C1/Cμ,=114 in the present study, which is much higher than the value 12.1 in the case with steady blowing jet circulation control.

关键词： synthetic jet circulation control numerical simulation lift enhancement

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The effect of actuation frequency on the plasma synthetic jet

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Science China(Technological Sciences) 2011年第11期54卷 2945-2950页

作者： zhang panfeng DAI ChenFeng LIU AiBing WANG JinJun Institute of Fluid Mechanics Beijing University of Aeronautics and Astronautics Beijing 100191 China Key Laboratory of Fluid Mechanics Ministry of Education Beijing 100191 China

The flow induced by plasma synthetic jet actuator was simulated through solving the Reynolds-averaged Navier-Stokes equations augmented by body force phenomenological plasma *** effect of actuation frequency on the plasma synthetic jet was examined by case *** numerical results present that with the actuation frequency increasing,the stream-wise distance of the adjacent vortex pairs induced by the actuator decreases monotonically,which is the same as the situation of the velocity fluctuations field caused by the vortex *** the actuation frequency is 60 Hz,the vortex pairs formed during the adjacent actuation periods merge together quickly,and the flow structure in the downstream region is more close to that of the steady *** actuation frequency has no visible influence on the time-averaged flow field of plasma synthetic ***,when the actuation frequency is relatively low(f<40 Hz),the momentum flux close to the actuator increases with the actuation frequency increasing,which is contrary to the situation in the far field from the wall.

关键词： plasma actuator synthetic jet numerical simulation actuation frequency

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Application of geographically weighted regression model in the estimation of surface air temperature lapse rate

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Journal of Geographical Sciences 2021年第3期31卷 389-402页

作者： QIN Yun REN Guoyu HUANG Yunxin zhang panfeng WEN Kangmin Department of Atmospheric Science School of Environmental StudiesChina University of GeosciencesWuhan 430074China Laboratory for Climate Studies National Climate CenterChina Meteorological AdministrationBeijing 100081China School of Resource and Environmental Science Hubei UniversityWuhan 430062China

The surface air temperature lapse rate(SATLR)plays a key role in the hydrological,glacial and ecological modeling,the regional downscaling,and the reconstruction of high-resolution surface air ***,how to accurately estimate the SATLR in the regions with complex terrain and climatic condition has been a great challenge for *** geographically weighted regression(GWR)model was applied in this paper to estimate the SATLR in China’s mainland,and then the assessment and validation for the GWR model were *** spatial pattern of regression residuals which was identified by Moran’s Index indicated that the GWR model was broadly reasonable for the estimation of *** small mean absolute error(MAE)in all months indicated that the GWR model had a strong predictive ability for the surface air *** comparison with previous studies for the seasonal mean SATLR further evidenced the accuracy of the ***,the GWR method has potential application for estimating the SATLR in a large region with complex terrain and climatic condition.

关键词： temperature lapse rate geographically weighted regression surface air temperature estimation regression residual

从国家自然科学基金资助看高超声速流动研究的发展现状

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航空学报 2015年第1期36卷 1-6页

作者：张攀峰詹世革国家自然科学基金委员会数理科学部北京100085

高超声速技术已经成为21世纪航空航天领域研究的制高点,许多发达国家都将其作为国家的战略目标。首先,分析了国家自然科学基金(NSFC)2000—2013年度在高超声速流动领域资助的项目情况;其次,对中国高超声速流动研究的主要研究方向、学科... 详细信息

高超声速技术已经成为21世纪航空航天领域研究的制高点,许多发达国家都将其作为国家的战略目标。首先,分析了国家自然科学基金(NSFC)2000—2013年度在高超声速流动领域资助的项目情况;其次,对中国高超声速流动研究的主要研究方向、学科交叉情况、主体研究队伍以及人才培养进行了介绍;最后,对未来需要重点关注的方向给出了建议。

关键词：国家自然科学基金资助项目高超声速流动飞行器

力学学科“十二五”国家自然科学基金项目申请和资助情况

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力学学报 2016年第1期48卷 243-253页

作者：张攀峰詹世革国家自然科学基金委员会数理科学部北京100085

对"十二五"期间力学学科国家自然科学基金项目的申请和资助情况进行了介绍,对5年期间总体趋势以及获资助主要单位和隶属关系进行了分析.着重介绍了面上项目、青年科学基金和地区科学基金的申请和资助情况,包括各分支学科以及研究领域的... 详细信息

对"十二五"期间力学学科国家自然科学基金项目的申请和资助情况进行了介绍,对5年期间总体趋势以及获资助主要单位和隶属关系进行了分析.着重介绍了面上项目、青年科学基金和地区科学基金的申请和资助情况,包括各分支学科以及研究领域的分布情况,项目申请人、负责人的年龄、职称和性别分布情况.对今后应该关注的问题给出了建议和措施.

关键词：国家自然科学基金力学十二五资助情况

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高校图书馆在公共文化服务中的知识传播效应

图书馆工作与研究 2011年第8期 48-50页

作者：张畔枫河北联合大学图书馆

本文从高校图书馆在公共文化服务体系建设中的作用这一视角,论述了高校图书馆在公共文化服务中的知识传播效应。从社会效应看,高校图书馆在面向社会进行知识传播中会产生和谐文化效应和教育社会化效应,同时又有提升自身的社会形象效应... 详细信息

本文从高校图书馆在公共文化服务体系建设中的作用这一视角,论述了高校图书馆在公共文化服务中的知识传播效应。从社会效应看,高校图书馆在面向社会进行知识传播中会产生和谐文化效应和教育社会化效应,同时又有提升自身的社会形象效应。从经济效应看,集中体现在知识溢出效应、文化扶贫效应、资源优化效应三个方面。

关键词：高校图书馆公共文化服务知识传播社会效应经济效应

合成射流控制NACA0015翼型大攻角流动分离

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北京航空航天大学学报 2008年第4期34卷 443-446页

作者：张攀峰王晋军北京航空航天大学航空科学与工程学院北京100083

为了研究合成射流激励器处于NACA0015翼型回流区时对其分离流动的控制,采用商用计算流体力学软件Fluent 6.1求解Reynolds平均Navier-Stokes方程,通过对翼型气动力特性、脱落漩涡结构以及射流孔口附近流动结构的分析,揭示了合成射流处于... 详细信息

为了研究合成射流激励器处于NACA0015翼型回流区时对其分离流动的控制,采用商用计算流体力学软件Fluent 6.1求解Reynolds平均Navier-Stokes方程,通过对翼型气动力特性、脱落漩涡结构以及射流孔口附近流动结构的分析,揭示了合成射流处于分离区时对边界层控制的机理.结果表明:当合成射流孔口处于回流区时仍可有效推迟翼面边界层分离点,缩小回流区范围,从而有效提高翼型的升力.当射流方向垂直于壁面,无量纲频率以及吹气速度比都等于1时,翼型平均升力系数提高40%左右.

关键词：失速分离流动合成射流流动控制