The effects of surface cooling on the stability of a flat-plate boundary layer in subsonic flow

The transition behaviour of a boundary layer with zero pressure gradient in a low-subsonic freestream is examined for a set of wall temperatures below the freestream temperature. Solutions of the boundary layer provided by both an incompressible and a compressible numerical flow solver are compared to wind tunnel measurements on a uniformly...

Influence of a Wall-Embedded Phononic Crystal on Tollmien-Schlichting Waves

This thesis concerns a numerical investigation for the stabilization (delay of laminar-to-turbulent transition) of ows over a at plate with a meta-unit of a possible metamaterial. The type of instability studied is that due to small disturbances in an incompressible, two-dimensional boundary layer. The linear growth of the disturbance in the...

Application of Acoustic Metamaterials in Boundary Layer Instability Control

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...