On Closing the Streamwise BiGlobal Stability Problem: The Effect of Boundary Conditions

The modal streamwise BiGlobal stability approach introduces problems regarding the specification of in- and outflow boundary conditions (BCs). Several conditions linked to lower hierarchical stability frameworks are elaborated and are applied to a freestream and boundary layer flow. The former case is used to demonstrate the odd-even decoupling...

Experimental investigation of aerofoil tonal noise generation

The present study investigates the mechanisms associated with tonal noise emission from a NACA 0012 aerofoil at moderate incidence (0; 1; 2 and 4 angle of attack) and with Reynolds numbers ranging from 100 000 to 270 000. Simultaneous time-resolved particle image velocimetry (PIV) of the aeroacoustic source region near the trailing edge and...

Atmospheric stability and wind profile climatology over the North Sea: Case study at Egmond aan Zee

The statistics of atmospheric stability and non-dimensional wind profiles are studied using the standard surface-layer theory at Egmond aan Zee in the North Sea. Measurements at 21, 70 and 116 m are used to validate the theoretical profiles. Charnock’s relation is used to estimate the sea surface roughness. Bulk Richardson number is used to...