Robust, High Sensitivity, Dynamic Wall Shear Sensors for Flow Diagnostics

Pavlos Vlachos，弗吉尼亚理工大学的剪切力测量以及剪切力对空气和水中飞行器粘性阻力的贡献对于许多应用来说都是至关重要的。用现有的最先进的测量技术无法获得在复杂的非定常流动中量化壁面剪切应力所需的灵敏度和准确性。这项研究工作提供了一种通过使用离子电活性聚合物换能器直接检测壁面剪切应力的范例转变。初步结果表明，这种活性材料对流体诱导的剪应力表现出极高的敏感性，具有高精度和高频率响应。此外，它还允许制造微型平头安装式传感器，消除了移动部件，提高了坚固性、易于实施并降低了成本。离子聚合物传感器从来没有被用于壁面剪切传感，因此提供剪切传感的机电耦合机制还不清楚。该计划将确定壁面剪切下离子聚合物传感器的基本传感特性，改进传感器的制造和封装，并将开发一种高频动态校准方法。本课程将探索从生物流体到经典空气动力学的各种可能的应用。这是一个由传感器倡议NSF 05-526支持的项目。

Abstract0510238PI: Pavlos Vlachos, Virginia TechWall shear stress measurements and the contribution of shear stresses to the viscous drag of air and water vehicles are critically important for numerous applications. The sensitivity and accuracy needed to quantify the wall shear stresses in complex unsteady flows is not attainable with the existing state-of-the-art measurement technologies. This research effort provides a paradigm shift in direct sensing of wall shear stresses by employing ionomeric electroactive polymer transducers. Preliminary results demonstrate that this active material exhibits exceptional sensitivity to flow-induced shear stress with high accuracy and high frequency response. In addition, it allows fabrication of miniature flush mountable sensors that eliminate moving parts increasing robustness, ease of implementation and reducing cost. Ionic polymer transducers have never been used for wall shear sensing thus the electromechanical coupling mechanism that provides shear transduction is not understood. This program will determine the fundamental sensing properties of ionic polymer transducers under wall shear will improve sensor fabrication and packaging and will develop a methodology for high frequency dynamic calibration. A variety of possible applications ranging from biofluids to classical aerodynamics will be explored. This is a project supported under the Sensor Initiative NSF 05-526.