Results 171 to 180 of about 104,934 (214)
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Toward dynamic separation without dynamic stall
Experiments in Fluids, 1988The concept of vorticity separation without dynamic stall is illustrated by flow visualization. A small airfoil with a rotating nose, originally built for the demonstration of static stall control, was placed in a wind tunnel and dynamically pitched. The flow around the airfoil during pitch was successfully visualized and filmed.
P. Freymuth, S. Jackson, W. Bank
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21st Aerospace Sciences Meeting, 1983
At freestream Mach numbers above M= 0 3 shock/boundary layer interaction begins to complicate the unsteady airfoil stall characteristics The present paper shows how theoretical relationships can be developed for the interdependence between unsteady and steady characteristics to provide the means whereby the shock induced dynamic stall characteristics ...
L. E. Ericsson, J. P. Reding
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At freestream Mach numbers above M= 0 3 shock/boundary layer interaction begins to complicate the unsteady airfoil stall characteristics The present paper shows how theoretical relationships can be developed for the interdependence between unsteady and steady characteristics to provide the means whereby the shock induced dynamic stall characteristics ...
L. E. Ericsson, J. P. Reding
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Aeronautical Quarterly, 1982
SummaryThe unsteady breakdown or stall of streamlined flow near the rounded leading edge of an aerofoil, as the small angle of attack is raised above its critical stall value, is studied theoretically for large Reynolds number motion. The unsteady developments take place first over a relatively slow time scale but then the corresponding solution breaks
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SummaryThe unsteady breakdown or stall of streamlined flow near the rounded leading edge of an aerofoil, as the small angle of attack is raised above its critical stall value, is studied theoretically for large Reynolds number motion. The unsteady developments take place first over a relatively slow time scale but then the corresponding solution breaks
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Influence of Rotation on Dynamic Stall
Journal of the American Helicopter Society, 2013A computational investigation of the effect of rotation on two-dimensional (2D) deep dynamic stall has been undertaken, showing that the effect of rotation is to reduce the severity of the pitching moment peak and cause earlier reattachment of the flow. A generic single blade rotor geometry was investigated, which had a pitching oscillation around the
Gardner, Anthony Donald, Richter, Kai
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Dynamic Stall Experiments on Oscillating Airfoils
AIAA Journal, 1975Dynamic stall and unsteady boundary layer separation have been studied in incompressible flow at moderately large Reynolds numbers. By varying the leading-edge geometry of an NACA 0012 airfoil, three different types of stall were produced. For most of the configurations studied, including the basic NACA 0012 profile, dynamic stall was found not to ...
W. MCCROSKEY, L. CARR, K. MCALISTER
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Revisiting unresolved dynamic stall phenomena
38th Aerospace Sciences Meeting and Exhibit, 2000In a series of dynamic stall tests, performed 1968 with a finite-span wing model having a NACA-0012 airfoil section, very unusual C,(a) characteristics were obtained by varying the Reynolds number as well as using fixed and free boundary layer transition.
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Dynamic stall on a supercritical airfoil
Aerospace Science and Technology, 2005Summary: For the present investigations of dynamic stall a supercritical airfoil was chosen. This new airfoil designed by DLR will be used in dynamic stall control research activities (project ADASYS) planned for the near future: the leading edge portion of the airfoil will be drooped down dynamically to improve dynamic stall characteristics on the ...
Geißler, W., Dietz, G., Mai, H.
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Analysis of Dynamic Stall using Dynamic Mode Decomposition Technique
31st AIAA Applied Aerodynamics Conference, 2013Dynamic mode decomposition is applied to investigate the unsteady flowfield around a pitching airfoil. The extracted flow structures are termed as dynamic mode decomposition modes. Analyses are performed for both attached flow and dynamic stall cases. Initially, flowfield data generated from numerical simulations are investigated.
Mariappan, Sathesh +3 more
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Modeling three-dimensional dynamic stall
Applied Mathematics and Mechanics, 2011The dynamic stall process in three-dimensional (3D) cases on a rectangular wing undergoing a constant rate ramp-up motion is introduced to provide a qualitative analysis about the onset and development of the stall phenomenon. Based on the enhanced understanding of the mechanism of dynamic stalls, a 3D dynamic stall model is constructed with the ...
Chao Lü, Tong-guang Wang
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Some Measurements on Dynamic Stall
Journal of Aircraft, 1974Details of a flow oscillation device and of force and moment measurements on a 2 ft chord twodimensional NACA 0012-64 airfoil in the oscillating flow and oscillated in pitch in a steady flow through stall are presented. Results indicate that both methods give essentially the same description of the dynamic stall process.
A. G. Parker, J. Bicknell
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