Time-resolved and time-averaged stereo-PIV measurements of a unit-ratio cavity
Open access
Datum
2016-06Typ
- Journal Article
Abstract
An experimental setup was developed to perform wind tunnel measurements on a unit-ratio, 2D open cavity under perpendicular incident flow. The open cavity is characterized by a mixing layer at the cavity top, that divides the flow field into a boundary layer flow and a cavity flow. Instead of precisely replicating a specific type of inflow, such as a turbulent flat plate boundary layer or an atmospheric boundary layer, the setup is capable of simulating a wide range of inflow profiles. This is achieved by using triangular spires as upstream turbulence generators, which can modify the otherwise laminar inflow boundary layer to be moderately turbulent and stationary, or heavily turbulent and intermittent. Measurements were performed by means of time-resolved stereo PIV. The cavity shear layer is analyzed in detail using flow statistics, spectral analysis, and space–time plots. The ability of the setup to generate typical cavity flow cases is demonstrated for characteristic inflow boundary layers, laminar and turbulent. Each case is associated with a distinct shear layer flow phenomena, self-sustained oscillations for the former and Kelvin–Helmholtz instabilities for the latter. Additionally, large spires generate a highly turbulent wake flow, resulting in a significantly different cavity flow. Large turbulent sweep and ejection events in the wake flow suppress the typical shear layer and sporadic near wall sweep events generate coherent vortices at the upstream edge. Mehr anzeigen
Persistenter Link
https://doi.org/10.3929/ethz-b-000117497Publikationsstatus
publishedExterne Links
Zeitschrift / Serie
Experiments in FluidsBand
Seiten / Artikelnummer
Verlag
SpringerThema
Particle Image Velocimetry; Wind Tunnel; Shear Layer; Turbulent Kinetic Energy; Street CanyonOrganisationseinheit
03806 - Carmeliet, Jan / Carmeliet, Jan
Anmerkungen
It was possible to publish this article open access thanks to a Swiss National Licence with the publisher.