Advances in Turbulence VI pp 357-360 | Cite as
Experimental Investigation of Nonlinear Wave Interactions and Secondary Instability in Three-Dimensional Boundary-Layer Flow
Abstract
The present DLR transition experiment was designed to study cross-flow (CF) instability development in the presence of controlled disturbance excitation. Therefore, a new type of disturbance generator has been developed, which basically consists of an array of 40 oscillating membranes depicted in figure 1. The membranes are flush mounted and oscillate sinusoidally with adjustable phase-lag by means of pressure fluctuations produced by loudspeakers. The whole generator system has been integrated in a flat plate model (figure 1). Previous extended measurements (Lerclie and Bippes, 1995) have shown that this disturbance generator excites single oblique traveling waves in agreement with local linear stability theory predictions. All subsequently presented results were obtained for an effective sweep angle of φ∞ = 43.5° and a freestream velocity of Q∞ = 16.3 m/s by hotwire anemometry using a sub-miniature V-type probe. The mean velocity components U,V and W correspond with x,y and z of the correspondingly denoted coordinate system.
Keywords
Direct Numerical Simulation Streamwise Vortex Freestream Velocity Secondary Instability Instability DevelopmentPreview
Unable to display preview. Download preview PDF.
References
- Arnal, D.Juillen, J.-C.(1978),Hot-wire conditional sampling techniques for transition intermittency studies,ONERA paper no80–22226Google Scholar
- Fischer,T.M.,Hein, S. & Dallmann, U (1993), A theoretical approach for describing secondary instability features in three-dimensional boundary-layer Rows,AIAA paper no 93–0080Google Scholar
- Kohama, Y. Saric, W.S., Hoos, J.A (1991), A high-frequency, secondary instability of crossflow vortices that leads to transition, Boundary-Layer Transition and Control Conference, Cambridge, UK Google Scholar
- Lerche,T.,Bippes H.(1995), Experimental investigation of cross-flow instability under the influence of controlled disturbance generation,Colloquium on Transitional Boundary Layers in Aeronautics of the Royal Netherlands Academy of Arts and Science Google Scholar
- MÜller, W.,Bestek, H. & Fasel, H.(1994), Spatial direct numerical simulation of transition in a three-dimensional boundary-layer,IUTAM Symposium on Laminar-Turbulent Transition, Sendai, Japan Google Scholar
- Poll,D.I.A (1985), Some observations of the transition process on the windward face of a long yawed cylinder,J. Fluid Mech. Vol. 150, pp. 329–356ADSCrossRefGoogle Scholar