Print Email Facebook Twitter Unsteady disturbances in a swept wing boundary layer due to plasma forcing Title Unsteady disturbances in a swept wing boundary layer due to plasma forcing Author Peng, K. (TU Delft Aerodynamics) Avallone, F. (TU Delft Wind Energy) Kotsonis, M. (TU Delft Aerodynamics) Date 2022 Abstract This work investigates the response of a transitional boundary layer to spanwise-invariant dielectric barrier discharge plasma actuator (PA) forcing on a 45 ° swept wing at a chord Reynolds number of 2.17 × 10 6. Two important parameters of the PA operation are scrutinized, namely, the forcing frequency and the streamwise location of forcing. An array of passive discrete roughness elements is installed near the leading edge to promote and condition a set of critical stationary crossflow (CF) instability modes. Numerical solutions of the boundary layer equations and linear stability theory are used in combination with the experimental pressure distribution to provide predictions of critical stationary and traveling CF instabilities. The laminar-turbulent transition front is visualized and quantified by means of infrared thermography. Measurements of velocity fields are performed using hotwire anemometry scans at specific chordwise locations. The results demonstrate the inherent introduction of unsteady velocity disturbances by the plasma forcing. It is shown that, depending on actuator frequency and location, these disturbances can evolve into typical CF instabilities. Positive traveling low-frequency type III modes are generally amplified by PA in all tested cases, while the occurrence of negative traveling high-frequency type I secondary modes is favored when PA is operating at high frequency and at relatively downstream locations, with respect to the leading edge. To reference this document use: http://resolver.tudelft.nl/uuid:b23a4b9d-bb92-42e5-a791-613b16f0dc81 DOI https://doi.org/10.1063/5.0124818 Embargo date 2023-05-15 ISSN 1070-6631 Source Physics of Fluids, 34 (11) Bibliographical note Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public. Part of collection Institutional Repository Document type journal article Rights © 2022 K. Peng, F. Avallone, M. Kotsonis Files PDF 5.0124818.pdf 4.15 MB Close viewer /islandora/object/uuid:b23a4b9d-bb92-42e5-a791-613b16f0dc81/datastream/OBJ/view