Determination of the Profile Drag of an Airplane Wing in Flight at High Reynolds Numbers (open access)

Determination of the Profile Drag of an Airplane Wing in Flight at High Reynolds Numbers

"Flight tests were made to determine the profile-drag coefficients of a portion of the original wing surface of an all-metal airplane and of a portion of the wing made aerodynamically smooth and more nearly fair than the original section. The wing section was approximately the NACA 2414.5. The tests were carried out over a range of airplane speeds giving a maximum Reynolds number of 15,000,000. Tests were also carried out to locate the point of transition from laminar to turbulent boundary layer and to determine the velocity distribution along the upper surface of the wing" (p. 483).
Date: January 6, 1939
Creator: Bicknell, Joseph
System: The UNT Digital Library
Calculation of the Aerodynamic Characteristics of Tapered Wings With Partial-Span Flaps (open access)

Calculation of the Aerodynamic Characteristics of Tapered Wings With Partial-Span Flaps

"Factors derived from wing theory are presented. By means of these factors, the angle of zero lift, the lift-curve slope, the pitching moment, the aerodynamic-center position, and the induced drag of tapered wings with partial-span flaps may be calculated. The factors are given for wings of aspect ratios 6 and 10 , of taper ratios from 0.25 to 1.00, and with flaps of various length. An example is presented of the method of application of the factors. Fair agreement with experimental results is shown for two wings of different taper ratio having plain flaps of various spacing" (p. 1).
Date: January 23, 1939
Creator: Pearson, Henry A. & Anderson, Raymond F.
System: The UNT Digital Library
Preliminary wind-tunnel investigation of an NACA 23012 airfoil with various arrangements of venetian-blind flaps (open access)

Preliminary wind-tunnel investigation of an NACA 23012 airfoil with various arrangements of venetian-blind flaps

Report presents the results of an investigation made in the NACA 7 by 10-foot wind tunnel of a large-chord NACA 23012 airfoil with several arrangements of venetian-blind flaps to determine the aerodynamic section characteristics as affected by the over-all flap chord, the chords of the slats used to form the flap, the slat spacing, the number of slats and the position of the flap with respect to the wing. Complete section data are given in the form of graphs for all the combinations tested.
Date: January 10, 1939
Creator: Wenzinger, Carl J. & Harris, Thomas A.
System: The UNT Digital Library
Static Thrust and Power Characteristics of Six Full-Scale Propellers (open access)

Static Thrust and Power Characteristics of Six Full-Scale Propellers

"Static thrust and power measurements were made of six full-scale propellers. The propellers were mounted in front of a liquid-cooled-engine nacelle and were tested at 15 different blade angles in the range from -7 1/2 degrees to 35 degrees at 0.75r. The test rig was located outdoors and the tests were made under conditions of approximately zero wind velocity" (p. 85).
Date: January 25, 1939
Creator: Hartman, Edwin P. & Biermann, David
System: The UNT Digital Library
Effect of exit-slot position and opening on the available cooling pressure for NACA nose-slot cowlings (open access)

Effect of exit-slot position and opening on the available cooling pressure for NACA nose-slot cowlings

Report presents the results of an investigation of full-scale nose-slot cowlings conducted in the NACA 20-foot wind tunnel to furnish information on the pressure drop available for cooling. Engine conductances from 0 to 0.12 and exit-slot conductances from 0 to 0.30 were covered. Two basic nose shapes were tested to determine the effect of the radius of curvature of the nose contour; the nose shape with the smaller radius of curvature gave the higher pressure drop across the engine. The best axial location of the slot for low-speed operation was found to be in the region of maximum negative pressure for the basic shape for the particular operating condition. The effect of the pressure operating condition on the available cooling pressure is shown.
Date: January 18, 1939
Creator: Stickle, George W.; Naiman, Irven & Crigler, John L.
System: The UNT Digital Library