Topic
Airfoil
About: Airfoil is a research topic. Over the lifetime, 24696 publications have been published within this topic receiving 337709 citations. The topic is also known as: aerofoil & wing section.
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TL;DR: In this paper, the configuration of viscous wakes of cascade blades is approximated from single airfoil experiments and the unsteady force and moment on a downstream blade passing through such wakes is calculated on the basis of the theory of isolated thin airfoils in nonuniform motion.
Abstract: The configuration of viscous wakes of cascade blades is approximated from single airfoil experiments. The unsteady force and moment on a downstream blade passing through such wakes is then calculated on the basis of the theory of isolated thin airfoils in nonuniform motion. The results indicate that the force is nearly proportional to the profile-drag coefficient of the upstream blades. For typical values of this coefficient and conventional cascade geometry the unsteady forces arising from passage through viscous wakes are of about the same size as those due to aerodynamic interference between the moving blade rows, previously estimated.
139 citations
TL;DR: In this article, a large-eddy simulation of turbulent flow separation over an airfoil and evaluate the effectiveness of synthetic jets as a separation control technique is performed and the results show that synthetic-jet actuation effectively delays the onset of flow separation and causes a significant increase in the lift coefficient.
139 citations
TL;DR: In this paper, a second-order Navier-Stokes solver is employed coupled with a membrane structural model suitable for the highly nonlinear structural response of the membrane, which results in a delay in stall with enhanced lift for higher angles of attack.
138 citations
18 Jun 1990
138 citations
Patent•
29 Aug 2001
TL;DR: In this paper, a wind harnessing system using a plurality of self supporting airfoil kites for production of useful power is described, where the kites are attached to a pivotal control housing by control lines 58 L and 58 R and support lines 60 L and 60 R and the entire process repeats starting with power stroke 140 a.
Abstract: A wind harnessing system using a plurality of self supporting airfoil kites 50 for production of useful power. The system comprising multiple airfoil kites 50 in tandem attached to a pivotal control housing 32 by control lines 58 L and 58 R and support lines 60 L and 60 R. Control lines 58 L and 58 R can change length with respect to the length of support lines 60 L and 60 R to control the airfoil kites' 50 angle-of-attack, pitch angle, direction of flight, and flight speed. The length of control lines 58 L and 58 R are controlled from ground station 30 by a movable pulley system in control housing 32 to adjust the airfoils' direction to follow a specific flight path 140. Control lines 58 R and 58 L and support lines 60 R and 60 L are also wound on a power shaft and pulley system in control housing 32. As the airfoil kites are propelled by the wind at very-high speed, the airfoils generate a powerful AXIAL force. The control lines 58 L and 58 R and support lines 60 L and 60 R are then reeled-out under this AXIAL tension causing the power shaft and pulley system in control housing 32 to turn a generator to generate electricity. After airfoil kites 50 have finished their reel-out power stroke 140 a, the airfoil's pitch angle is made negative so they can be reeled-in by their control and support lines using a minimum of force along path 140 b. Once the airfoils have been rewound to the proper distance, the airfoils are again angled for high-speed operation to generate powerful AXIAL force and reeled-out along 140 c to provide another power stroke. The airfoil kites are then reeled-in again along path 140 d and the entire process repeats starting with power stroke 140 a. Since the force to rewind the airfoils is much less than the force generated during reel-out, there is net power generated.
138 citations