后缘尾流

采用两台LaVision ImagerProX4M相机和两台CMOS相机构成一套可以测量两个互相垂直平面的2D2C和2D3C速度矢量场的粒子成像测速系统。用于带侧后缘锥度方型背车辆低频尾流动力学研究。

采用一台Quantronix公司生产的Darwin Duo型双腔Nd:YLF激光器作光源。该激光器输出2 × 25 mJ 单脉冲能量，重复频率1 kHz。采用两台Photron Fastcam SA1 相机作成像器件。构成一套时间分辨高重复频率立体3维粒子成像测量系统。对NACA 0018翼型，加装整齐排列的锯齿状后缘时的流动的边界层特性和声学特性进行了测量。和未加装翼型的特性做比较，得到加装锯齿状后缘，可降低气动噪声的结论。

The unsteady organization and the evolution of thecoherent structures within the immediate wake of the sharpsymmetric trailing-edge of a NACA0012 airfoil is investigatedusing two-component (2C) and tomographic particle imagevelocimetry (Tomo-PIV). The inspection of the Tomo-PIVresults showed new vortical structures, introduced here ascounter-hairpin vortices, evolve in the wake region to directthe turbulent mechanism towards recovery of the wake deficit.These vortical structures are topologically similar to thehairpins of a turbulent boundary layer as they appear to be Ushapedbut with inverted orientation. The spanwise portion ofa counter-hairpin vortex is in the vicinity of the wakecenterline and the legs are inclined at an approximately 60degree to the wake axis in the downstream direction. Theypartially wrap around the high speed streaks and frequentlysweep the high-speed flow towards the wake centerline. Apattern recognition algorithm is applied to establishcharacterization based on an ensemble averaged counterhairpinvortex. The formation mechanism of the counterhairpinvortices is attributed to the shear layer produced alongthe wake centerline by the neighboring of a low and a highspeed streak which promotes formation of spanwise vorticesthat form the vortex by connection to quasistreamwisevortices.

采用英国Litron公司LPY 703-200型, 200 Hz PIV激光器作光源。两台Photron 1024 PCI型高速相机作为成像组件，构成一套高速时间分辨粒子成像测速系统。同时用多台高速相机记录两种食虫性蝙蝠飞行的运动学特征。同步同时测量运动学特征和尾流结构。并分析其特点规律。

采用德国LaVision公司的软件平台和四台Imager SX 4M型CCD相机。构成一套层析PIV处理系统。并利用这样的系统对受到漩涡诱导振动（VIV）影响的系留球体尾流进行了Tomo-PIV测量。

采用德国LaVision的Imager Pro X4M CCD相机和蔡司ZEISS 50mm f/2 Makro 镜头，测量了亚音速高马赫数跨音速涡轮叶栅尾流的2D2C速度矢量场并和五孔探针的测量结果进行了对比分析。

采德国LaVision公司的两相机2D3C立体PIV测量系统和集成一体化的4台相机构成的MiniShaker测试系统，对水下导管螺旋桨尾流流场进行了测量和理论分析。

The unsteady lift generated by the flow of turbulence over the trailing edge of an airfoil can be aneffective source of dipole sound. The objective of the present research was to experimentally measurethe velocity field behind an asymmetric 45 degree beveled trailing edge in order to develop an understandingof the flow mechanisms responsible for the generation of trailing edge noise. Particle ImageVelocimetry (PIV) data were acquired in the near wake region of the trailing edge at a chord Reynoldsnumber of 1.9x106. The time averaged velocity statistics are indicative of a wake flow containingsemi-periodic vortex shedding. These large scale shedding motions are commonly responsible for thetonal noise produced by the trailing edge. A phase average decomposition of the velocity field withrespect to this shedding process was utilized to separate the small scale turbulent motions responsiblefor broadband sound production. This analysis has shown that the characteristics of the small scaleturbulence are dependent on the phase of the vortex shedding process.

The three dimensional near wake flow topology behind a blunt trailing edge flat plate isinvestigated for a Reynolds number range varying from 500 to 4.6x104 using a combination offlow visualization, numerical simulations and experiments. The secondary wake instabilities areidentified using vorticity maps from CFD and performing Proper Orthogonal Decomposition(POD) on PIV data from experiments to identify the underlying dominant coherent structures.These structures are found to appear at a spanwise spacing ranging from 2.2 to 4.8. At higherReynolds numbers the secondary wake instabilities appear to be unsteady in space and time.

A survey is conducted to quantitatively visualise the wake flow behind a circular cylinder at Reynolds numbers of 180 to 2500. A time-resolved tomographic PIV method is used to measure thesequence of three-dimensional vector fields evolving in time. The attention is focused upon the unsteady 3D wake organization with the interaction of primary rollers (Karman-Benard) and the secondary vortices resulting from 3D instability of the vortex wake.

给出了蝙蝠飞行的实验测量结果。包括直线和回转飞行时的运动特性高帧频记录，以及蝙蝠飞行方向后部尾流漩涡的测量。

The wakes of wall mounted circular cylinders of very lowaspect ratio have been investigated in a wind tunnel. Besidesplanar PIV, also high resolution tomographic PIV was usedto capture the flow phenomena downstream of the cylinder.By changing the velocity U￥ and the cylinder height h at aconstant aspect ratio L = h=D, a wide database of differentflow conditions was obtained. The resulting relative height ofthe boundary layer thickness d was 0:6 h=d 2:5, while theReynolds number based on the length l between leading edgeand cylinder centre Rel was 57 000 Rel 188 000. A pair ofcounter-rotating vortices was found in the wake of the cylinder.The rotation sense is such, that in the center of the wake apositive vertical velocity component results. Also horseshoevortices were found next to these trailing vortices. The relativeheight of the incoming boundary layer has a large impact on thedevelopment, strength and dissipation of the vortex system.

We study experimentally the impulse response of a cylinder wake below the critical Reynoldsnumber of the Bé nard–von Ká rmá n instability. In this subcritical regime, a localized inhomogeneousregion of convective instability exists which causes initial perturbations to be transiently amplified.The aim of this work is to quantify the evolution resulting from this convective instability usingtwo-dimensional particle image velocimetry in a hydrodynamic tunnel experiment. The velocityfields allow us to describe the evolution of wave packets in terms of two control parameters: theReynolds number and the magnitude of the imposed perturbation. The temporal evolution of energyexhibits a transient algebraic growth at short times followed by an exponential decay.

Ship laboratory has specific components forunderwater measurements􀁺 system used for phase-locked measurementsbehind the propeller for a twin-screw vessel􀁺 the purpose of the study has been to− gain information on the interaction of the propeller andthe rudder− explore the capabilities of the measurement system

对医用防护fu产品质量控制检测总结的标准要求及解决方案，希望我们山东普创工业科技能够在这特殊的“抗疫"时期为防护服生产企业及质检单位提供有效的后援力量。

1, a=radius). The experiments use conventional test methods in conjunction with Stereo Particle Image Velocimetry (SPIV) measurement techniques to evaluate the flow in the boundary region of a small diameter flexible cylinder towed in the high speed towing basin at the Naval Surface Warfare Center Carderock Division (NSWCCD). The flexible cylinders are approximately neutrally buoyant and have an initial length of 152 m and radii of 0.45 mm and 1.25 mm. The first objective for this experiment is to evaluate the streamwise development of wall shear stress (τw) and momentum thickness (θ) in axisymmetric turbulent boundary layers using drag measurements at 3.1, 5.2, 9.3 and 14.4 m/s for comparison to existing data. The second and primary objective for this experiment is to determine the streamwise development of the axisymmetric boundary layer flow and to evaluate relevant boundary layer parameters at 3.8, 7.7, 12.9 and 15.4 m/sec using SPIV images acquired over the entire length of the cylinders. Drag measurements reveal that the wall shear stress is large and that the momentum thickness grows slowly when compared to flat plate boundary layers. The velocity field data shows that the boundary flow remains turbulent over the entire length of the flexible cylinder and that the turbulent profile is different from that of flat plate boundary layers.

The far wake trajectory of the tumbling tip vortex effect of a reduced-scale, 1 m diame-ter, four-bladed rotor during hover is studied using vortex methods combined with a centerof mass analysis approach. Measurements of all three components of the velocity field areacquired using a stereo PIV system synchronized to capture up to 800 wake age of thevortex with 10 offsets during hover conditions. The nominal operating condition of therotor is at a rotational speed of 1520RPM, corresponding to Rec = 248,000 with a chordlength of 58.5mm. The rotor was operated with a pitch of 7.2± 0.5 and a CT / of 0.029.The far wake vortex tumbling phenomenon is captured and described. It is shown thattip vortices from two blades tumble through approximately 180 of rotation before theycoalesce. It is seen that the parent vortices are stronger than the daughter vortex, but dueto vortex stretching the daughter vortex has a smaller radius with greater swirl strength.An accurate characterization and prediction of the trajectory of the far wake vortex tum-bling can enhance the ability to predict and alleviate the resuspension of particles duringbrownout as well as provide a database for far wake validation of CFD codes.

本方法参考 NY/T 761-2008 方法，建立了采用双三元液相色谱配合 AXP 泵辅助柱后衍生，实现了 8 种氨基甲酸酯农药的检测，最低检测限可达 0.008~0.015mg/L，满足 NY/T 761-2008 的要求。

本方法参考 NY/T 761-2008 方法，建立了采用双三元液相色谱配合 AXP 泵辅助柱后衍生，实现了 8 种氨基甲酸酯农药的检测，最低检测限可达 0.008~0.015mg/L，满足 NY/T 761-2008 的要求。

本方法参考 NY/T 761-2008 方法，建立了采用双三元液相色谱配合 AXP 泵辅助柱后衍生，实现了 8 种氨基甲酸酯农药的检测，最低检测限可达 0.008~0.015mg/L，满足 NY/T 761-2008 的要求。

本研究对5种超高压微射流压力 0、30、60、90、120 MPa 处理下的猕猴桃果酒样品的品质进行检测，以期为选择超高压微射流技术处理猕猴桃果酒提供技术参考。

本方法参考 NY/T 761-2008 方法，建立了采用双三元液相色谱配合 AXP 泵辅助柱后衍生，实现了 8 种氨基甲酸酯农药的检测，最低检测限可达 0.008~0.015mg/L，满足 NY/T 761-2008 的要求。

本方法参考 NY/T 761-2008 方法，建立了采用双三元液相色谱配合 AXP 泵辅助柱后衍生，实现了 8 种氨基甲酸酯农药的检测，最低检测限可达 0.008~0.015mg/L，满足 NY/T 761-2008 的要求。

本方法参考 NY/T 761-2008 方法，建立了采用双三元液相色谱配合 AXP 泵辅助柱后衍生，实现了 8 种氨基甲酸酯农药的检测，最低检测限可达 0.008~0.015mg/L，满足 NY/T 761-2008 的要求。

本方法参考 NY/T 761-2008 方法，建立了采用双三元液相色谱配合 AXP 泵辅助柱后衍生，实现了 8 种氨基甲酸酯农药的检测，最低检测限可达 0.008~0.015mg/L，满足 NY/T 761-2008 的要求。

本方法参考 NY/T 761-2008 方法，建立了采用双三元液相色谱配合 AXP 泵辅助柱后衍生，实现了 8 种氨基甲酸酯农药的检测，最低检测限可达 0.008~0.015mg/L，满足 NY/T 761-2008 的要求。

采用LaVision公司的ImagerIntense型相机和可编程时间控制单元PTU，Nd:YAG激光器和另外一台高速770Hz高速相机，测量研究了氧气在气泡中向液体扩散过程。

利用Lasertec显微镜，实现透明晶圆的全面自动缺陷检查、以及3D形貌测量。

饲粮中添加后生元对断奶仔猪生长性能、腹泻率、抗氧化能力及粪便微生物菌群的影响

人肿瘤相关抗原(TAA)检测试剂盒人肿瘤相关抗原(TAA)检测试剂盒使用说明书本试剂盒仅供研究使用。检测范围： 规格：96T/48T使用目的：本试剂盒用于测定人血清,血浆及相关液体样本中人肿瘤相关抗原(TAA)含量。实 验 原 理 本试剂盒应用双抗体夹心酶标免疫分析法测定标本中人肿瘤相关抗原(TAA)水平。用纯化的抗体包被微孔板，制成固相抗体，往包被单抗的微孔中依次加入人肿瘤相关抗原(TAA)抗原、生物素化的人肿瘤相关抗原(TAA)抗体、HRP标记的亲和素，经过彻底洗涤后用底物TMB显色。TMB在过氧化物酶的催化下转化成蓝色，并在酸的作用下转化成最终的黄色。颜色的深浅和样品中的人肿瘤相关抗原(TAA)呈正相关。 使用酶标仪在450nm波长下测定吸光度（OD值），计算样品浓度。