The effect of dive recovery flaps on the lift of a two dimensional symmetrical airfoil with changes in chordwise location of the flaps

• Main Authors: Weitzenfeld, Daniel Kehr, Trauger, Robert James, Kronmiller, George Hannibal
• Format: Others
• Published: 1946
• Online Access: https://thesis.library.caltech.edu/4673/1/Weitzenfeld_dk_1946.pdf; Weitzenfeld, Daniel Kehr and Trauger, Robert James and Kronmiller, George Hannibal (1946) The effect of dive recovery flaps on the lift of a two dimensional symmetrical airfoil with changes in chordwise location of the flaps. Engineer's thesis, California Institute of Technology. doi:10.7907/CV3E-KC83. https://resolver.caltech.edu/CaltechETD:etd-11262008-112929 <https://resolver.caltech.edu/CaltechETD:etd-11262008-112929>

NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. It was desired in this investigation to determine the effect of the chordwise position of dive recovery flaps on the lift of a laminar flow, low drag, two-dimensional airfoil at high subsonic Mach numbers. Schlieren pictures were taken to relate the formation, extension and strength of shock waves to the measured lift. Tests were made on a four inch chord airfoil of section 65,1-012 at Mach numbers from .50 to .83, a Reynolds number of 1,600,000 at M[subscript o] = 0.7, angles of attack from 1 to 3 degrees, and flap locations at 15%, 30%, and 45% chord; the flap is 10% of the chord. The investigation was carried out by the authors at the Guggenheim Aeronautical Laboratory of the California Institute of Technology during the school year 1945-1946. It was concluded that dive recovery flaps materially increase the lift of an airfoil, and there is an optimum flap location for maximum lift and one for maximum […]. Moreover, it was concluded that the formation and development of shock waves is directly related to the lift, but that the successive development of the shock wave pattern as a function of Mach number is independent of angle of attack or flap location; the Mach number for initial shock formation varies. Finally, in this tunnel where the thickness of the boundary layer is a large percent of the tunnel width the correction for non-uniform spanwise lift distribution must be investigated more carefully before absolute lift values can be computed.