Measurement of unsteady surface forces by means of piezoelectrical copolymer coatings

Abstract

The Pressure Sensitive Copolymer Coating (PSC) with piezoelectric properties is introduced as a new surface measurement technique. In contrast to conventional surface measurement techniques the PSC combines high spatial and temporal resolution, and can be applied to arbitrarily formed surfaces. The linear relationship between the mechanical pressure and the electrical voltage due to the piezoelectric effect is established by calibration measurements. Furthermore, first applications in transition experiments in incompressible as well as in compressible flows are presented. Finally, investigations of the flow around a wall mounted cylinder are presented. © 2007 Springer-Verlag Berlin Heidelberg.