Low-speed Experimental Investigation of a Thin, Faired, Double-wedge Airfoil Section with Nose and Trailing-edge Flaps

Low-speed Experimental Investigation of a Thin, Faired, Double-wedge Airfoil Section with Nose and Trailing-edge Flaps
Author: Leonard M. Rose
Publisher:
Total Pages: 28
Release: 1949
Genre: Aerofoils
ISBN:

A faired, double-wedge airfoil section, 4.23 percent thick, was investigated with plain nose and trailing-edge flaps. The nose flap was 0.16 chord of the airfoil and the trailing-edge flap was 0.25 chord of the airfoil. Section lift, drag, and pitching-momnet data are presented for a Reynolds number of 5,800,000 which corresponded to a Mach number of 0.17.

An Experimental Investigation of the Aerodynamic Effects of Forward Facing Wedges on the Upper Surface and Leading Edge of an Aerofoil, with Emphasis at High Angles of Attack

An Experimental Investigation of the Aerodynamic Effects of Forward Facing Wedges on the Upper Surface and Leading Edge of an Aerofoil, with Emphasis at High Angles of Attack
Author: A. P. Brown
Publisher:
Total Pages: 12
Release: 1983
Genre: Aerofoils
ISBN: 9780642078797

Wind tunnel tests were carried out to determine the effect on the longitudinal aerodynamic characteristics of a two-dimensional aerofoil fitted with descrete forward-facing wedges (base to aerofoil chord ratio 0.24 and 0.39) at the leading edge and on the upper surface of the aerofoil. The forward-facing wedges were conceived as a means of delaying stall and enhancing lift at high incidence. Thus these may be useful in low speed flight (approach and landing) where they would be extended from the clean wing surface along with the trailing edge flaps. Tests were conducted at Mach numbers 0.2/0.3, over an incidence range of -10 to +20 degrees. Corresponding chord Reynolds numbers were 0.57 and 0.84 million (compared to an inflight value of 2.5 million for a wing of chord 1.25 metres and airspeed of 60 knots). The results at M=0.2 are more extensive than those at M=0.3.

Experimental Investigation of the Flow Around Lifting Symmetrical Double-wedge Airfoils at Mach Numbers of 1.30 and 1.41

Experimental Investigation of the Flow Around Lifting Symmetrical Double-wedge Airfoils at Mach Numbers of 1.30 and 1.41
Author: Paul B. Gooderum
Publisher:
Total Pages: 86
Release: 1956
Genre: Aerofoils
ISBN:

Measurements were made of the flow around a 10-percent-thick, double symmetrical, two-dimensional wedge at a Mach number of 1.30 and of a 14.2-percent-thick wedge at Mach numbers of 1.30 and 1.41 for various angles of attack up to 5 degrees. Results were thus obtained in the vicinity of the theoretically interesting region between shock attachment and the lower limit for completely supersonic flow over the surface of the airfoil. Pressure and Mach number distributions, lift and drag coefficients, center of lift, and pitching moment are presented for the angles of attack used. By means of the transonic similarity laws, the results are compared with each other, with small-disturbance theory, and with shock-expansion theory wherever possible. The data show that pressure distributions on wedges of different thickness and Mach number are similar at the same values of transonic similarity parameter and reduced angle of attack for angles of attack as large as the thickness ratio; that the lift-curve slope is approximately independent of the angle of attack for an angle-of-attack range from -2 degrees to 2 degrees; and that, for the airfoils tested at Mach numbers greater than the attachment value, the center-of-pressure location is nearly independent of the angle of attack, the variation being to plus or minus 3 percent chord for the angles of attack used in this investigation. For the airfoil tested at a Mach number slightly less than the shock-attachment value, the center-of-pressure location was only roughly independent of the angle of attack, the variation of this location being to plus or minus 6 percent chord.

Theoretical and Experimental Investigation of the Aerodynamic Properties of Airfoils Near Stall in a Two

Theoretical and Experimental Investigation of the Aerodynamic Properties of Airfoils Near Stall in a Two
Author: G. R. Ludwig
Publisher:
Total Pages: 118
Release: 1966
Genre:
ISBN:

A theoretical method, which requires the use of a digital computer, was developed to predict pressure distributions on an airfoil in an inviscid two-dimensional monuniformly sheared flow. The theory is applicable to airfoils of arbitrary profile and to nonuniformly sheared flows which can be represented by segments with linear velocity profiles. To test the developed theory, aerodynamic characteristics of an airfoil were investigated both theoretically and experimentally in a relatively simple two-dimensional nonuniformly sheared flow consisting of two segments with shears of equal magnitude but of opposite sign. Agreement between computed and experimental pressure distributions was good and on the basis of these results, a mechanism is postulated by which the large variations in lift previously observed in a two-dimensional nonuniformly sheared flow can occur. (Author).