A parametric study has been conducted into the effects of device height (), Mach number (), and Reynolds number ( to ) on the effectiveness of microramp vortex generators as flow control devices. The control authority of the microramp comes from the two counter-rotating vortices it introduces into the boundary layer. The vortices transport high-momentum fluid toward the wall, thus creating a fuller velocity profile that is less prone to separation. This momentum transport, however, comes at the price of a low-momentum wake that is formed downstream of the device. The induced flowfield has been studied by means of two-dimensional particle image velocimetry, oil-flow, and schlieren visualizations. Most of the geometric flow features were found to scale linearly with microramp height : the wake height, wake strength, vortex core height, and the momentum flux added to the near-wall region of the flow all increase linearly with . The control effectiveness of the microramp in the symmetry plane is reduced for higher Mach numbers () as the strength of the vortices is reduced, which adds less momentum to the near-wall region of the flow. Also, a stronger wake is recorded for the higher Mach number cases. Only a weak Reynolds number effect is observed, with the microramp becoming slightly more effective at higher Reynolds numbers.
Mach and Reynolds Number Effects on the Wake Properties of Microramps
AIAA Journal ; 54 , 11 ; 3481-3494
01.11.2016
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
Mach and Reynolds Number Effects on the Wake Properties of Microramps
Online Contents | 2016
|Mach and Reynolds Number Effects on the Wake Properties of Microramps
Online Contents | 2016
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