Low-Speed Investigation of a Double Wedge Airfoil with a Leading-Edge Slat

Citation

Wallace, Richard Earl (1952) Low-Speed Investigation of a Double Wedge Airfoil with a Leading-Edge Slat. Engineer's thesis, California Institute of Technology. doi:10.7907/NJPD-HF21. https://resolver.caltech.edu/CaltechETD:etd-03302009-084539

Abstract

NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. A two-dimensional investigation was undertaken in the California Institute of Technology Merrill Wind Tunnel to determine the effectiveness of using a 15% slat on a 10% double wedge airfoil. The investigation was conducted in three phases: force polars, pressure tests, and tuft pattern studies. All phases were conducted at a dynamic pressure of 40 lb/ft[superscript 2], equivalent to a Reynolds number of 0.78 x 10[superscript 6]. The high lift characteristics of the double wedge airfoil with the slat were found to be aerodynamically superior to those of the basic wedge section and the wedge equipped with a plain nose flap. Extension of the leading edge slat caused increases in maximum lift coefficients and in the angle of attack required for maximum lift. The following increments were measured. […]. The nose deflection produced larger […] max increments than the slot variations below nose angles of 25° but for 25° and larger angles the slot variations caused the major improvements in […]. The slot prevented occurrence of buffeting caused by upper surface intermittent or oscillatory separation experienced with the plain nose flap. In all of the cases tested with the slat extended, the stall was more gradual than for the basic section. The stall for the optimum slot conditions was the result of trailing edge separation moving forward over the upper surface of the airfoil.

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