MEMS壁面剪切应力传感器研究进展

The development progress of MEMS wall shear stress sensors

壁面剪切应力的时间特性是用于反映单个动量运输过程中非稳态结构的一个测量参数,也是湍流中相干位点的一个表征方法,是一个重要的壁面湍流的物理量。目前,主要基于近壁或壁面处的平均速度梯度和换热率与壁面切应力成正比的基础上对MEMS壁面剪切应力开展研究。因此,对MEMS壁面剪切应力传感器进行综述。根据不同的测量方式,MEMS剪切应力传感器主要分为直接测量和间接测量两种类型。对每种测量方法的原理、研究现状、优点和限制进行分析。MEMS技术使得剪切应力传感器取得显著的进步,提高空间和时间分辨率,以及测量结果的准确度。但MEMS剪切应力传感器还需要进一步发展,并且量化测量中的不确定度,才能成为一种可靠的剪切应力测量技术。最后,对未来MEMS剪切应力传感器的发展方向进行总结。

Time characteristic of wall shear stress, not only a measurement parameter used toreflect unsteady structure during individual momentum transport in flow state, but also acharacterization method of corresponding points in turbulence, is an important physical indicatorforwall turbulence. At present, the research on MEMS wall shear stress is mainly based on the factthatmean velocity gradient and heat transfer rate near the wall or on wall surface is proportional tothe wall shear stress on wall surface. So this paper summarizes the MEMS wall shear stresssensor. MEMS shear stress sensors are divided into direct measurement and indirect measurementtypes according to the different ways of measurement. The principles, research status, advantagesand limitations of each measurement method have also been analyzed. The wall shear stresssensors have made a significant progress via MEMS technology, which improved the spatial andtemporal resolution. However, MEMS shear stress sensors need further development, and it'suncertainty should be quantified in order to become a reliable shear stress measurementtechnology. Finally, the future development directions of the MEMS shear stress sensors aresummarized.