Detailed flow-field measurements were performed downstream of a single vortex generator (VG) using a Stereo Digital Particle Image Velocimetry system. The passive flow-control devices examined consisted of a low-profile VG with a device height, h, approximately equal to 20 percent of the boundary-layer thickness, Δ, and a conventional VG with h ≈ Δ. Flow-field data were taken at twelve cross-flow planes downstream of the VG to document and quantify the evolution of embedded streamwise vortex. Key parameters including vorticity, circulation, trajectory, and half-life radius—describing concentration, strength, path, and size, respectively—of the device-induced streamwise vortex were extracted from the flow-field data. Peak vorticity and circulation for the low-profile VG decayed exponentially to the distance downstream from the device. The device-height normalized vortex trajectories for the low-profile VG, especially in the lateral direction, followed the general trends of the conventional VG.
Flow-Field Measurement of Embedded Streamwise Vortex Generated from Passive Flow-Control Devices
Chung-Sheng YaoRelated information
1 NASA Langley Research Center Flow Physics and Control Branch, Mail Stop 170, Hampton, VA 23681-2199, USA
, John LinRelated information1 NASA Langley Research Center Flow Physics and Control Branch, Mail Stop 170, Hampton, VA 23681-2199, USA
, Brian AllanRelated information1 NASA Langley Research Center Flow Physics and Control Branch, Mail Stop 170, Hampton, VA 23681-2199, USA
Published Online: April 02, 2010
Abstract