A piezoelectric sensor performing shear stress measurement in an hydrodynamic flow

The knowledge of the mean shear stress and of its fluctuations in the hydrodynamic boundary layer requires high sensitivity sensor. The principle of a floating element type sensor using piezoelectric bimorphs bending has been studied for this application. This transducer can perform direct measurement of shear stresses with a satisfactory accuracy. The transducer has first been embedded for its waterproofing and its behaviour in air has been optimised with the heap of both Finite Element Modelling and experimental calibration. Finally, the influence of normal stresses and hydrodynamic pressure on the embedded transducer have been evaluated.