Visualization and wake surveys of vortical flow over a delta wing
1988; American Institute of Aeronautics and Astronautics; Volume: 26; Issue: 2 Linguagem: Inglês
10.2514/3.9864
ISSN1533-385X
AutoresF. M. Payne, Tammy Ng, Robert C. Nelson, Lewis B. Schiff,
Tópico(s)Computational Fluid Dynamics and Aerodynamics
ResumoAn experimental investigation of vortex breakdown on delta wings at high angles of attack is presented. Smoke flow visualization and the laser light sheet technique were used to obtain cross-sectional views of the leading-edge vortices as they break down for a series of flat-plate delta wings having sweep angles of 70, 75, 80, and 85 deg. At low tunnel speeds (as low as 3 m/s), details of the flow that are usually imperceptible or blurred at higher speeds can be clearly seen. A combination of lateral and longitudinal cross-sectional views provides information on the three-dimensional nature of the vortex structure before, during, and after breakdown. Whereas details of the flow are identified in still photographs, the dynamic characteristics of the breakdown process have been recorded using high-speed movies. Velocity measurements have been obtained using a laser Doppler anemometer with the 70 deg delta wing at 30 deg angle of attack. The measurements show that, when breakdown occurs, the core flow is transformed from a jet-like to a wake-like flow.
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