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微型柔性热敏传感器阵列应用研究 总被引:1,自引:0,他引:1
边界层分离点检测是实现分离流主动控制的前提和基础,也是气动控制灵巧蒙皮系统研究的重点和难点。以流体边界层分离点检测技术为研究对象,以流体边界层分离点判定的风洞实验为验证目标,设计制作微型热敏传感器与聚酰亚胺柔性衬底,并首次利用微装配技术集成分立敏感元件与柔性衬底形成热敏传感器阵列。首先,采用分立元件通过表面贴装工艺来实现柔性微型热膜传感器阵列的集成,并研究该传感器阵列中敏感元件、柔性衬底的设计及传感器的排布。然后,在低速风洞实验中对传感器阵列的性能和传感器阵列输出信号采用统计量算法的方式进行处理判断,判定圆柱翼型的流体分离点位置。最后,对实验的结果所作的分析表明,该微型柔性热敏传感器阵列满足流体分离检测系统实时性、动态性的要求。 相似文献
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低速流体边界层分离检测试验 总被引:1,自引:0,他引:1
结合边界层分离点附近的切应力变化规律,对边界层分离特性进行研究,确定边界层分离点的判定依据.采用分立元件通过表面贴装工艺来实现柔性微型热膜传感器阵列的集成,并研究该传感器阵列中敏感元件、柔性衬底的设计及传感器的排布,解决柔性传感器阵列对微细加工工艺要求较高的难题.根据边界层分离点判定依据,在低速风洞试验中对传感器阵列的性能和传感器阵列输出信号采用统计量算法和傅里叶变换功率谱算法进行处理判断,并与计算流体力学仿真结果对比,结果表明制造的微型热敏传感器阵列能够实现对流体边界层分离位置的在线测量. 相似文献
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微型热敏剪应力传感器在航空航天等领域有重要应用价值,然而基于热敏感原理的间接剪应力测量会引入流体环境温度的影响.结合热敏剪应力传感嚣的热交换模型,研究了流体环境温度变化的影响机理.分析了常用温度修正方法的应用局限性,设计了结合流体温度、从信号处理角度修正传感器输出的温度补偿方法,没有增加电路复杂程度,显著提高了测量精度.测试实验表明:当流体环境温度在10~20℃范围变化时,温度造成的输出信号偏移误差从原来的2%/℃降低到了0.5%/℃,证明了该方法的有效性. 相似文献
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依据三维边界层理论,提出了一个计算径向无叶扩压器内三维湍流边界层分离点的简单近似方法;并利用此方法计算了不同扩压器进口条件下的边界层分离点的位置的变化规律;在此基础上,讨论了在某些条件下离心式压缩机无叶扩压器内发生的旋转失速现象及由此导致的离心式压缩机的喘振机理。 相似文献
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An experimental study was conducted in order to investigate unsteady boundary layers for a pitching airfoil. An NACA0012 airfoil
sinusoid-pitched at quarter chord was employed, and its mean angle-of-attack and oscillation amplitude were 0° and 6°, respectively.
To explore the unsteady boundary layers, smoke-wire visualization and surface-mounted probe measurements were pursued for
three different cases, varying with Reynolds numbers (Rec=2.3×104, 3.3×104, and 4.8×104). A reduced frequency of 0.1 was identically set in all cases. Results show that in the presented Reynolds number range,
the separation bubble dependent on both angle-of-attack and Reynolds number was observed, accompanied with unsteady laminar
separation after reattachment. The unsteady laminar separation occurred at the saddle point, which was formed by the two vortices,
the wall, and the external flow, and it was independent of reverse flow. This result indicates that the unsteady laminar separation
occurs during the process of transition after the reattachment of separated boundary layer for an unsteady flow. The reverse
flow observed over the trailing edge significantly interacted with the trailing edge vortex that rotates in the streamwise
direction. This trailing edge vortex prevents the uppermost of the reverse flow from reaching to the unsteady laminar separation
point during the upstroke, and this induces that the boundary layer breakdown does not occur in spite of the occurrence of
laminar separation. The discrete vortices are formed by unsteady laminar separation, and its formation is ultimately affected
by the Reynolds number. Consequently, it is obvious that the unsteady boundary layers are ultimately sensitive to Reynolds
number in a low Reynolds number regime. 相似文献
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V. Kr. Shrn 《International Journal of Mechanical Sciences》1975,17(9):557-563
The results of an investigation of the characteristics of the flow around building models in terms of the various stagnation points are reported. The influence of the mean velocity profile, turbulence intensity, percentage boundary layer immersion ratio and the building model's aspect ratio on the location of the various stagnation points was studied from the point of view of simulating the minimum fraction of the atmospheric boundary layer in a wind tunnel for building aerodynamics investigations. It is suggested that the atmospheric boundary layer height of at least two to three times the building height should be simulated in a wind tunnel for studying the effects of strong and gusty winds on buildings and structures. 相似文献
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设计并实现一种基于工业互联网的数控机床数据采集平台,实现远程感测、实时监测和功能动态扩展,并能为后续远程诊断提供安全可靠的数据。该数据平台基于工业互联网的,采用MTconnect协议标准,在物理层实现物理机床的和传感器的部署;在网络层开发适配器和代理服务器模块,实现数据平台的实时监测和动态拓展;在应用层开发了对采集数据的处理的数据可视化平台,并能支持不同的机器学习算法用于对所采集数据的分析。系统设计中对数据采集进行优化,在一个周期内发现数据有变化才将数据上传到数据平台,从而避免大量数据传输造成网络的延迟和冗余。最后通过实验,验证所开发的数据采集平台的有效性,满足数控机床对数据采集与分析的需求。 相似文献
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为了提高机器人与外界环境的安全交互性能,基于导电面电势分布理论和封闭气体压缩定律提出一种适用于机器人曲表面的触觉传感器模型,实现了接触位置与接触压力的检测。传感器采用三层结构,包括导电层、压缩气体隔离层和信号提取层。为了适应任意曲面形状,降低导电层电势非线性分布影响,采用机器学习算法对电势分布模型进行重建。采用COMSOL软件对传感器导电层进行物理建模与仿真,并制备了传感器样品。仿真和实验结果表明,提出的触觉传感器模型可以定制于机器人曲表面上,并能实现接触位置和接触压力的实时检测,可用于人机信息交互。 相似文献