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涡流恢复导叶对螺旋桨气动和声学性能影响研究

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推进技术 2024年第5期45卷 63-75页

作者：韦卿张武陈正武仝帆朱文浩王良军上海大学力学与工程科学学院上海市应用数学与力学研究所上海200072 中国空气动力研究与发展中心气动噪声控制重点实验室四川绵阳621000 上海大学信息化办公室上海200444

为了对比安装涡流恢复导叶与单排螺旋桨气动性能和气动噪声的差异,采用数值模拟的方法研究了安装六种不同间距涡流恢复导叶和单排螺旋桨的气动力及气动噪声。研究结果表明:在起飞状态,级间距Δx=0.27的工况下,安装涡流恢复导叶使得推力... 详细信息

为了对比安装涡流恢复导叶与单排螺旋桨气动性能和气动噪声的差异,采用数值模拟的方法研究了安装六种不同间距涡流恢复导叶和单排螺旋桨的气动力及气动噪声。研究结果表明:在起飞状态,级间距Δx=0.27的工况下,安装涡流恢复导叶使得推力系数增加6.4%,效率增加6.7%。随着间距的增大,前级叶片的桨尖涡、尾迹涡等涡系结构在通过后级叶片时破碎并向下游传播,且强度逐渐减小。噪声强度随着级间距的增加而逐渐减小,最大级间距涡流恢复导叶的噪声与最小级间距涡流恢复导叶噪声相比降低5.7 dB,噪声下降幅度随级间距的增加逐渐减缓,存在级间距最优位置使得推力增加最大,噪声强度适中。

关键词：对转螺旋桨涡流恢复导叶桨尖涡尾迹涡干涉噪声

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抗虫优质茶树新品种‘苔选0310号’

园艺学报 2024年第S1期51卷 233-234页

作者：李燕杨春乔大河密孝增陈娟郭燕梁思慧陈正武贵州省茶叶研究所贵州省茶种质创新工程技术研究中心贵阳550006

‘苔选0310号’是从‘湄潭苔茶’中无性繁殖育成的抗虫优质茶树新品种。中晚生,中叶类,小乔木。树姿直立,分枝部位较高,密度中等,叶片上斜状着生。制绿茶,条索紧结、较显毫;汤色浅嫩黄、清澈明亮,香气高爽,滋味较甘鲜;制红茶,紧结、较... 详细信息

‘苔选0310号’是从‘湄潭苔茶’中无性繁殖育成的抗虫优质茶树新品种。中晚生,中叶类,小乔木。树姿直立,分枝部位较高,密度中等,叶片上斜状着生。制绿茶,条索紧结、较显毫;汤色浅嫩黄、清澈明亮,香气高爽,滋味较甘鲜;制红茶,紧结、较显金毫、较乌,汤色红艳明亮,香气鲜甜有果香,滋味鲜醇。适合在西南茶区及相似地区种植。

关键词：茶树抗虫优质品种

贵州两地野生茶树叶片解剖结构比较及抗逆性分析

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河南农业科学 2024年第1期53卷 48-61页

作者：杨春苏胜峰杨代星梁思慧郭燕郭灿陈正武贵州省农业科学院茶叶研究所贵州贵阳550006 盘州市淤泥乡农村工作中心贵州盘州553537 贵州大学茶学院贵州贵阳550025

为更好地开发和利用贵州省盘州市及三都县的野生茶树种质,以24份野生茶树为材料,比较两地野生茶树叶片形态特征和叶片解剖结构特征共23个叶片性状,并结合隶属函数法分析野生茶树的抗逆性。结果表明,盘州和三都两地的野生茶树,在叶片表... 详细信息

为更好地开发和利用贵州省盘州市及三都县的野生茶树种质,以24份野生茶树为材料,比较两地野生茶树叶片形态特征和叶片解剖结构特征共23个叶片性状,并结合隶属函数法分析野生茶树的抗逆性。结果表明,盘州和三都两地的野生茶树,在叶片表观上存在明显区别,盘州野生茶树的叶长、叶宽和叶面积极显著大于三都野生茶树,长宽比则极显著小于三都野生茶树。盘州和三都野生茶树在叶片厚度、栅栏组织厚度、细胞数、主脉厚度、草酸钙晶体密度等16个叶片解剖结构性状上存在显著或极显著差异,相较于三都野生茶树,盘州野生茶树的叶片厚度、栅栏组织厚度、海绵组织厚度、主脉厚度更厚,栅栏组织细胞排列更紧密,草酸钙晶体密度更大,上(下)表皮细胞厚度更薄。相关性分析显示,23个叶片性状间相关性较强,有43对呈极显著正相关,23对呈显著正相关,17对呈极显著负相关,12对呈显著负相关。聚类分析结果显示,24份野生茶树可分为4类,主脉厚度和维管束短径是主要划分依据。抗性评价结果显示,盘州野生茶树在抗旱性和抗寒性上略优于三都野生茶树。根据平均隶属函数值排序,筛选出SD-20-2、SD-20-3、PZ-05和PZ-09四份综合抗性较优的野生茶树,可作为高抗野生茶树种质选育抗逆性茶树品种。

关键词：野生茶树叶片解剖结构栅栏组织抗逆性贵州

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Feedback control of boundary layer Tollmien-Schlichting waves using a simple model-based controller

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Chinese Journal of Aeronautics 2021年第3期34卷 25-38页

作者： Yong LI zhengwu chen School of Mechanical and Electrical Engineering Wenzhou UniversityWenzhou 325035China Key Laboratory of Aerodynamic Noise Control China Aerodynamic Research and Development CenterMianyang 621000China

The attenuation of spatially evolving instability Tollmien-Schlichting(T-S)waves in the boundary layer of a flat plate with zero pressure gradients using an active feedback control scheme is theoretically and numerically *** boundary layer is excited artificially by various perturbations to create a three-dimensional field of instability *** of actuators and sensors are distributed locally at the wall surface and connected together via a feedback *** key elements of this feedback control are the determination of the dynamic model of the flat plate boundary layer between the actuators and the sensors,and the design of the model-based feedback *** dynamic model is established based on the linear stability calculation which simulates the three-dimensional input-output behaviour of the boundary *** simplify the control problem,an uncoupled control mode of the dynamic model is made to capture only those dynamics that have greatest influences on the input-output behaviour.A Proportional-Integral-Derivative(PID)controller,i.e.a lead-lag compensator,combining with a standard Smith predictor is designed based on the system stability criterion and the specifications using frequency-response *** performance of the feedback control with the uncoupled control mode is demonstrated by the large reduction of the three-dimensional disturbances in the boundary *** simple feedback control is realistic and competitive in a practical implementation of T-S wave cancellation using a limited number of localised sensors and actuators.

关键词： Boundary layer instability Control system Feedback control PID controller Tollmien-Schlichting waves

Pressure field measurements on large-scale propeller blades using pressure-sensitive paint

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Acta Mechanica Sinica 2022年第2期38卷 35-45,I0001页

作者： Chunhua Wei Lingrui Jiao Fan Tong zhengwu chen Yingzheng Liu Di Peng China Aerodynamic Research and Development Center Mianyang 621000China Key Lab of Education Ministry for Power Machinery and Engineering School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China Gas Turbine Research Institute Shanghai Jiao Tong UniversityShanghai 200240China

Pressure-sensitive paint(PSP)is a global pressure measurement *** with pressure transducers,PSP has significant advantages such as high spatial resolution and a lack of contact when applied to fast-rotating ***,due to the limitations of other pressure measurement techniques,the validation of PSP measurements on fast-rotating blades is generally *** this work,a comprehensive study including PSP measurement,force balance measurement,and simulation was conducted on a 1 m-diameter propeller at the China Aerodynamic Research and Development ***,our computational fluid dynamics(CFD)code was validated by comparing the calculated aerodynamic thrust with the results from force balance ***,the pressure distributions on the propeller blade obtained by PSP were carefully compared with the CFD results under different working *** results of PSP measurements,force balance measurements,and CFD showed good agreement,and the PSP measurement errors were estimated to be less than 5% of the dynamic pressure at the blade ***,the variations in pressure distribution under different rotating speeds and free-stream velocities were discussed.

关键词： Pressure-sensitive paint Pressure distribution Propeller blade

Experimental investigation of self-oscillation feedback flow field structure and flow induced aeroacoustics for an open cavity in low speed wind tunnel

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Chinese Journal of Acoustics 2022年第4期41卷 358-372页

作者： LIANG Yong chen Yingchun ZHAO Kun WANG Yong YUE Tingrui chen zhengwu Low Speed Institute China Aerodynamics Research and Development CenterMianyang 621000 School of Aeronautics Northwestern Polytechnical UniversityXi'an 710072 Commercial Aircraft Corporation of China Ltd.Shanghai 201200

To investigate the noise issue caused by open-cavity self-sustained oscillations,flow over a rectangular cavity with a length-to-depth ratio of 2 at Mach numbers of 0.10,0.15,0.20,and 0.25 was experimentally studied in a 0.55 m×0.40 m aeroacoustics wind ***,the velocity field and self-sustained oscillation were ***-frequency particle image velocimetry was employed to visualise the flow-field structure and analyse the path of the acoustic and pressure *** acoustic self-sustaining oscillation modes and duct modes were investigated by testing the far field and the fluctuating wall ***,the characteristics of the correlation between the wall pressure and the acoustic performance were *** results demonstrated that apart from the main vortex structure,shear vortices at the leading edge and crash vortices at the trailing edge were ***,around the frequencies of 875 Hz,1288 Hz,1875 Hz,and 2050 Hz,an evident tonal noise,induced by the cavity oscillation,could be *** addition,the wall pressure strongly correlated with the far-field noise,and the tone appeared at the same frequencies where the peaks occurred in the wall pressure spectra.

关键词： oscillation flow field

贵州两地野生大厂茶嘌呤生物碱与儿茶素组分比较

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浙江农业学报 2024年第6期36卷 1232-1244页

作者：杨春杨代星苏胜峰梁思慧李燕郭燕乔大河密孝增陈正武贵州省农业科学院茶叶研究所贵州贵阳550006 贵州大学茶学院贵州贵阳550025 盘州市淤泥乡农村工作中心贵州盘州553523

探明普安和盘州两地野生大厂茶生化差异,为贵州野生大厂茶资源的保护与开发利用提供科学依据,以普安和盘州两地40份野生大厂茶为材料,采用高效液相色谱法(HPLC)测定大厂茶春季一芽二叶新梢的嘌呤生物碱组分和儿茶素组分和含量,并结合聚... 详细信息

探明普安和盘州两地野生大厂茶生化差异,为贵州野生大厂茶资源的保护与开发利用提供科学依据,以普安和盘州两地40份野生大厂茶为材料,采用高效液相色谱法(HPLC)测定大厂茶春季一芽二叶新梢的嘌呤生物碱组分和儿茶素组分和含量,并结合聚类分析和正交偏最小二乘判别分析(OPLS-DA),对两地大厂茶种质资源进行类别区分和关键差异化合物筛选。结果表明,两地大厂茶种质资源中主要嘌呤生物碱不同,普安大厂茶为咖啡碱,盘州大厂茶为苦茶碱。表儿茶素没食子酸酯(epigallocatechin gallate,ECG)和表儿茶素(epicatechin,EC)是大厂茶中含量较突出的儿茶素组分。两地大厂茶的苦茶碱、咖啡碱、没食子酸、儿茶素(catechin,C)和表儿茶素(epicatechin,EC)含量存在极显著差异,普安大厂茶中咖啡碱和没食子酸含量平均值分别为28.53 mg·g^(-1)和0.29 mg·g^(-1),极显著高于盘州大厂茶(2.92 mg·g^(-1)和0.13 mg·g^(-1))。盘州大厂茶中苦茶碱、C和EC含量平均值分别是22.88、2.37、36.83 mg·g^(-1),极显著高于普安大厂茶(1.58、1.81、26.55 mg·g^(-1))。相关性分析显示,11个生化成分间相关性较强,有14对呈显著或极显著正相关,16对呈显著或极显著负相关。聚类分析结果显示:40份野生大厂茶可分为3类,第Ⅰ类为30份盘州大厂茶种质资源,主要生化特点是苦茶碱和C含量较高,咖啡碱含量较低;10份普安大厂茶资源被分作两类,GT-PA-03等7份种质资源构成第Ⅱ类,它们的咖啡碱、EC和ECG含量较高,苦茶碱、没食子酸、表没食子儿茶素(epigallocatechin,EGC)、C、表没食子儿茶素没食子酸酯(epigallocatechin gallate,EGCG)含量较低;GT-PA-01、GT-PA-02和GT-PA-09组成第Ⅲ类,它们的没食子酸、EGC和EGCG含量较高。OPLS-DA分析结果显示,咖啡碱、苦茶碱和没食子酸是区分普安和盘州两地大厂茶的关键生化因子。40份大厂茶种质资源中筛选出高苦茶碱(>25.0 mg·g^(-1))种质3份,高没食子儿茶素没食子酸酯(gallocatechin gallate,GCG)(>15.0 mg·g^(-1))种质2份,高ECG(>80.0 mg·g^(-1))种质3份,高EC(>50.0 mg·g^(-1))种质3份。

关键词：普安盘州大厂茶苦茶碱咖啡碱

High-Order Discontinuous Galerkin Method for Hovering Rotor Simulations Based on a Rotating Reference Frame

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Transactions of Nanjing University of Aeronautics and Astronautics 2019年第1期36卷 57-70页

作者： ZHANG Tao Lü Hongqiang QIN Wanglong chen zhengwu Department of Aerodynamics Nanjing University of Aeronautics and Astronautics China Aerodynamics Research and Development Center

An implicit higher ? order discontinuous Galerkin(DG) spatial discretization for the compressible Euler equations in a rotating frame of reference is presented and applied to a rotor in hover using hexahedral grids. Instead of auxiliary methods like grid adaptation,higher ? order simulations(fourth ? and fifth ? order accuracy) are *** numerical experiments are carefully designed,conducted and analyzed. The results show generally excellent consistence with references and vigorously demonstrate the higher?order DG method's better performance in loading distribution computations and tip vortex capturing, with much fewer degrees of freedom(DoF). Detailed investigations on the outer boundary conditions for hovering rotors are presented as well. A simple but effective speed smooth procedure is developed specially for the DG method. Further results reveal that the rarely used pressure restriction for outlet speed has a considerable advantage over the extensively adopted vertical speed restriction.

关键词： high-order method(HOM) discontinuous Glaerkin method(DGM) Euler equation hovering rotor simulation tip vortex

Implicit discontinuous Galerkin method on agglomerated high-order grids for 3D simulations

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Chinese Journal of Aeronautics 2016年第6期29卷 1496-1505页

作者： Qin Wanglong Lyu Hongqiang Wu Yizhao Zhou Shijie chen zhengwu Department of Aerodynamics Nanjing University of Aeronautics and AstronauticsNanjing 210016China China Aerodynamics Research and Development Center Mianyang 621000China

High quality of geometry representation is regarded essential for high-order methods to maintain their high-order accuracy. An agglomerated high-order mesh generating method is investigated in combination with discontinuous Galerkin(DG) method for solving the 3D compressible Euler and Navier-Stokes equations. In this method, a fine linear mesh is first generated by standard commercial mesh generation tools. By taking advantage of an agglomeration method, a quadratic high-order mesh is quickly obtained, which is coarse but provides a high-quality geometry representation, thus very suitable for high-order computations. High-order discretizations are performed on the obtained grids with DG method and the discretized system is treated fully implicitly to obtain steady state solutions. Numerical experiments on several flow problems indicate that the agglomerated high-order mesh works well with DG method in dealing with flow problems of curved geometries. It is also found that with a fully implicit discretized system and a p-sequencing method, the DG method can achieve convergence state within several time steps which shows significant efficiency improvements compared to its explicit counterparts.

关键词： Agglomeration Discontinuous Galerkin(DG) High-order Implicit scheme Navier-Stokes equations