Print Email Facebook Twitter Boundary layer state detection using piezoelectric sensors Title Boundary layer state detection using piezoelectric sensors Author Stuber, V.L. (TU Delft Novel Aerospace Materials) Kotsonis, M. (TU Delft Aerodynamics) van der Zwaag, S. (TU Delft Novel Aerospace Materials) Date 2022 Abstract Two piezoelectric series bimorph sensors were embedded below the skin of a NACA 0012 symmetrical airfoil to detect the local state of the boundary layer during wind tunnel testing. Small vanes piercing the airfoil skin were glued onto the bimorphs providing a mechanical coupling to the local mechanical force fluctuations imparted by the local unsteady boundary layer flow. The state of the boundary layer at the sensor sites was varied by changing the angle of attack. The objective of this work was to establish the ability of this sensor concept to accurately distinguish among typical boundary layer states such as attached laminar flow, turbulent flow and separated flow. The output of the sensor was compared to concurrent time-resolved particle image velocimetry measurements, which served as a validation technique. Using the developed sensor response envelope, a single data point time series of the piezo electrical signal was proven to be sufficient to accurately detect the boundary layer state on classical airfoils in the low Reynolds number regime. In projected future applications, single or arrays of bimorph sensors can be used to map the boundary layer of more complex or morphing shape airfoils. The fast response of the sensor can in principle be utilised in closed-loop flow control systems, aimed at drag reduction or lift enhancement. Subject laminar-to-turbulent transitionparticle image velocimetrypiezoelectricityseparationwind tunnel experiments To reference this document use: http://resolver.tudelft.nl/uuid:2bba02ed-bb4f-43f8-bc72-ab9c8dc4678e DOI https://doi.org/10.1088/1361-665X/ac3900 ISSN 0964-1726 Source Smart Materials and Structures, 31 (1) Part of collection Institutional Repository Document type journal article Rights © 2022 V.L. Stuber, M. Kotsonis, S. van der Zwaag Files PDF Stuber_2022_Smart_Mater._ ... 015014.pdf 3.12 MB Close viewer /islandora/object/uuid:2bba02ed-bb4f-43f8-bc72-ab9c8dc4678e/datastream/OBJ/view