TY - GEN
T1 - Experimental investigation of jet mixing of a co-flow jet airfoil
AU - Dano, B. P.E.
AU - Kirk, D.
AU - Zha, G. C.
N1 - Copyright:
Copyright 2010 Elsevier B.V., All rights reserved.
PY - 2010
Y1 - 2010
N2 - The jet mixing of a co-flow jet (CFJ) airfoil is investigated to understand the mechanism of lift enhancement, drag reduction, and stall margin increase. Digital Particle Image Velocimetry, flow visualization and aerodynamic forces measurements are used to reveal the insight of the CFJ airfoil mixing process. At low AoA and low momentum coefficient, the mixing between the wall jet and mainflow is dominant with large structure coherent structures for the attached flows. When the momentum coefficient is increased, the large vortex structure disappears. At high AoA with flow separation, the CFJ creates a upstream flow strip between two counter rotating vertical shear layer, i.e., the outer shear layer and inner flow induced by CFJ. The UFS is characterized with large vortex free region. The co-flow wall jet is deflected normal to the airfoil surface characterized with a saddle point. With increased momentum coefficient of the CFJ, the saddle point moves downstream and eventually disappears when the flow is attached. Turbulence plays a key role in mixing the CFJ with mainflow to transport high kinetic energy from the jet to mainflow so that the mainflow can remain attached at high AoA to generate high lift. When the flow is separated, increased CFJ momentum coefficient also increases the turbulence intensity at jet injection mixing region.
AB - The jet mixing of a co-flow jet (CFJ) airfoil is investigated to understand the mechanism of lift enhancement, drag reduction, and stall margin increase. Digital Particle Image Velocimetry, flow visualization and aerodynamic forces measurements are used to reveal the insight of the CFJ airfoil mixing process. At low AoA and low momentum coefficient, the mixing between the wall jet and mainflow is dominant with large structure coherent structures for the attached flows. When the momentum coefficient is increased, the large vortex structure disappears. At high AoA with flow separation, the CFJ creates a upstream flow strip between two counter rotating vertical shear layer, i.e., the outer shear layer and inner flow induced by CFJ. The UFS is characterized with large vortex free region. The co-flow wall jet is deflected normal to the airfoil surface characterized with a saddle point. With increased momentum coefficient of the CFJ, the saddle point moves downstream and eventually disappears when the flow is attached. Turbulence plays a key role in mixing the CFJ with mainflow to transport high kinetic energy from the jet to mainflow so that the mainflow can remain attached at high AoA to generate high lift. When the flow is separated, increased CFJ momentum coefficient also increases the turbulence intensity at jet injection mixing region.
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M3 - Conference contribution
AN - SCOPUS:78649515810
SN - 9781600867453
T3 - 5th Flow Control Conference
BT - 5th Flow Control Conference
T2 - 5th Flow Control Conference
Y2 - 28 June 2010 through 1 July 2010
ER -