Print Email Facebook Twitter Application of Acoustic Metamaterials in Boundary Layer Instability Control Title Application of Acoustic Metamaterials in Boundary Layer Instability Control Author de Koning, Coert (TU Delft Aerospace Engineering) Contributor Kotsonis, M. (mentor) Michelis, Theodorus (mentor) Degree granting institution Delft University of Technology Programme Aerospace Engineering | Aerodynamics and Wind Energy Date 2021-04-23 Abstract To achieve delay of laminar-to-turbulent transition of boundary layers, the application of acoustic metamaterial concepts is investigated. This is done analytically, numerically and experimentally by studying the interaction between a Helmholtz resonator and a TS wave. A Helmholtz resonator can serve as a meta-atom in a metamaterial. The desired wall controller property of a metamaterial to suppress TS waves is evaluated. This study shows that TS wave attenuation is achieved if the wall-normal velocity from a metamaterial is in-phase with the TS wave pressure. TS wave amplification is obtained if the pressure and velocity are more than (approximately) 90 degrees out of phase. The p-v phase relation corresponding to a Helmholtz resonator only remains in the amplification regime. Therefore, the conclusion is drawn that a single Helmholtz resonator can only amplify TS waves. If an acoustic metamaterial concept is found where pressure and wall-normal velocity are in-phase, this can be useful in boundary layer instability control. Subject Boundary Layer TransitionMetamaterialsAcoustic MetamaterialsHelmholtz resonatorPIV/PTVTollmien-Schlichting waves To reference this document use: http://resolver.tudelft.nl/uuid:2903b86e-bc2b-44c4-8b8c-32bc2e74fbde Part of collection Student theses Document type master thesis Rights © 2021 Coert de Koning Files PDF Msc_Thesis_CdeKoning.pdf 8.25 MB Close viewer /islandora/object/uuid:2903b86e-bc2b-44c4-8b8c-32bc2e74fbde/datastream/OBJ/view