You limited your search to:

  Partner: UNT Libraries Government Documents Department
 Decade: 1930-1939
 Serial/Series Title: NACA Technical Notes
 Collection: Technical Report Archive and Image Library
The 6-foot-4-inch wind tunnel at the Washington Navy Yard

The 6-foot-4-inch wind tunnel at the Washington Navy Yard

Date: August 1, 1935
Creator: Desmond, G L & Mccrary, J A
Description: The 6-foot-4-inch wind tunnel and its auxiliary equipment has proven itself capable of continuous and reliable output of data. The real value of the tunnel will increase as experience is gained in checking the observed tunnel performance against full-scale performance. Such has been the case of the 8- by 8-foot tunnel, and for that reason the comparison in the calibration tests have been presented.
Contributing Partner: UNT Libraries Government Documents Department
An accurate method of measuring the moments of inertia of airplanes

An accurate method of measuring the moments of inertia of airplanes

Date: October 1, 1930
Creator: Miller, M P
Description: This note contains a description of an improved apparatus and procedure used by the NACA for determining the moments of inertia of airplanes. The method used, based on the pendulum theory, is similar to that previously used, but a recent investigation of its accuracy has resulted in the improvements described herein. The error, when using the new apparatus and procedure, has been found to be of the order of 1 per cent.
Contributing Partner: UNT Libraries Government Documents Department
Adhesion of ice in its relation to the de-icing of airplanes

Adhesion of ice in its relation to the de-icing of airplanes

Date: August 1, 1939
Creator: Rothrick, A M & Selden, R
Description: The various possible means of preventing ice adhesion on airplane surfaces are critically reviewed. Results are presented of tests of the adhesives forces between ice and various solid and liquid forces. It is concluded that the de-icing of airplane wings by heat from engine exhaust shows sufficient promise to warrant full-scale tests. For propellers, at least, and possibly for certain small areas such as windshields, radio masts, etc. the use of de-icing or adhesion-preventing liquids will provide the best means of protection.
Contributing Partner: UNT Libraries Government Documents Department
Advantages of oxide films as bases for aluminum pigmented surface coatings for aluminum alloys

Advantages of oxide films as bases for aluminum pigmented surface coatings for aluminum alloys

Date: November 1, 1931
Creator: Buzzard, R W & Mutchler, W H
Description: Both laboratory and weather-exposure corrosion tests showed conclusively that the protection afforded by aluminum pigmented spar varnish coatings applied to previously anodized aluminum surfaces was greatly superior to that afforded by the same coatings applied to surfaces which had simply been cleaned free from grease and not anodized.
Contributing Partner: UNT Libraries Government Documents Department
The aerodynamic analysis of the gyroplane rotating-wing system

The aerodynamic analysis of the gyroplane rotating-wing system

Date: March 1, 1934
Creator: Wheatley, John B
Description: An aerodynamic analysis of the gyroplane rotating-wing system is presented herein. This system consists of a freely rotating rotor in which opposite blades are rigidly connected and allowed to rotate or feather freely about their span axis. Equations have been derived for the lift, the lift-drag ratio, the angle of attack, the feathering angles, and the rolling and pitching moments of a gyroplane rotor in terms of its basic parameters. Curves of lift-drag ratio against lift coefficient have been calculated for a typical case, showing the effect of varying the pitch angle, the solidarity, and the average blade-section drag coefficient. The analysis expresses satisfactorily the qualitative relations between the rotor characteristics and the rotor parameters. As disclosed by this investigation, the aerodynamic principles of the gyroplane are sound, and further research on this wing system is justified.
Contributing Partner: UNT Libraries Government Documents Department
The aerodynamic characteristics of a model wing having a split flap deflected downward and moved to the rear

The aerodynamic characteristics of a model wing having a split flap deflected downward and moved to the rear

Date: May 1, 1932
Creator: Weick, Fred E & Harris, Thomas E
Description: Tests were made on a model wing with three different sized split trailing-edged flaps, in the NACA 7 by 10 foot wind tunnel. The flaps were formed of the lower rear portion of the wing and were rotated downward about axes at their front edges. The lift, drag, and center of pressure were measured with the axis in its original position and also with it moved back in even steps to the trailing edge of the main wing, giving in effect an increase in area. The split flaps when deflected about their original axis locations gave slightly higher maximum lift coefficients than conventional trailing-edge flaps, and the lift coefficients were increased still further by moving the axes toward the rear. The highest value of C(sub L max), which was obtained with the largest flap hinged at 90 per cent of the chord from the leading edge, was 2.52 as compared with 1.27 for the basic wing.
Contributing Partner: UNT Libraries Government Documents Department
The aerodynamic characteristics of airfoils as affected by surface roughness

The aerodynamic characteristics of airfoils as affected by surface roughness

Date: April 1, 1933
Creator: HOCKER RAY W
Description: The effect on airfoil characteristics of surface roughness of varying degrees and types at different locations on an airfoil was investigated at high values of the Reynolds number in a variable density wind tunnel. Tests were made on a number of National Advisory Committee for Aeronautics (NACA) 0012 airfoil models on which the nature of the surface was varied from a rough to a very smooth finish. The effect on the airfoil characteristics of varying the location of a rough area in the region of the leading edge was also investigated. Airfoils with surfaces simulating lap joints were also tested. Measurable adverse effects were found to be caused by small irregularities in airfoil surfaces which might ordinarily be overlooked. The flow is sensitive to small irregularities of approximately 0.0002c in depth near the leading edge. The tests made on the surfaces simulating lap joints indicated that such surfaces cause small adverse effects. Additional data from earlier tests of another symmetrical airfoil are also included to indicate the variation of the maximum lift coefficient with the Reynolds number for an airfoil with a polished surface and with a very rough one.
Contributing Partner: UNT Libraries Government Documents Department
The aerodynamic characteristics of airfoils at negative angles of attack

The aerodynamic characteristics of airfoils at negative angles of attack

Date: March 1, 1932
Creator: Anderson, Raymond F
Description: A number of airfoils, including 14 commonly used airfoils and 10 NACA airfoils, were tested through the negative angle-of-attack range in the NACA variable-density wind tunnel at a Reynolds Number of approximately 3,000,000. The tests were made to supply data to serve as a basis for the structural design of airplanes in the inverted flight condition. In order to make the results immediately available for this purpose they are presented herein in preliminary form, together with results of previous tests of the airfoils at positive angles of attack. An analysis of the results made to find the variation of the ratio of the maximum negative lift coefficient to the maximum positive lift coefficient led to the following conclusions: 1) For airfoils of a given thickness, the ratio -C(sub L max) / +C(sub L max) tends to decrease as the mean camber is increased. 2) For airfoils of a given mean camber, the ratio -C(sub L max) / +C(sub L max) tends to increase as the thickness increases.
Contributing Partner: UNT Libraries Government Documents Department
Aerodynamic characteristics of anemometer cups

Aerodynamic characteristics of anemometer cups

Date: February 1, 1934
Creator: Brevoort, M J & Joyner, U T
Description: The static lift and drag forces on three hemispherical and two conical cups were measured over a range of angles of attack from 0 degrees to 180 degrees and a range of Reynolds Numbers from very small up to 400,000. The problems of supporting the cup for measurement and the effect of turbulence were also studied. The results were compared with those of other investigators.
Contributing Partner: UNT Libraries Government Documents Department
Aerodynamic characteristics of several airfoils of low aspect ratio

Aerodynamic characteristics of several airfoils of low aspect ratio

Date: August 1, 1935
Creator: Zimmerman, C H
Description: This paper presents the results of wind-tunnel tests of several airfoils of low aspect ratio. The airfoils included three circular Clark Y airfoils with different amounts of dihedral, two Clark Y airfoils with slots in their portions, and three flat-plate airfoils. Lift, drag, and pitching-moment characteristics of the slotted airfoils with slots open and closed; pitching moment characteristics of one of the slotted airfoils with slots open and closed; and lift characteristics of the flat-plate airfoils are included. The results reveal a definite improvement of lift, drag, and pitching-moment characteristics with increase in dihedral of the circular Clark Y wing. Lift characteristics near the stall were found to depend markedly on the shape of the extreme tip but were not greatly affected by slots through the after portion of the airfoils. Changes in plan form of the flat-plate airfoils gave erroneous indications of the effect to be expected from changes in plan form of an airfoil of Clark Y section. The minimum drag characteristics of the circular Clark Y airfoils were found to be substantially the same as for a Clark Y airfoil of conventional aspect ratio.
Contributing Partner: UNT Libraries Government Documents Department
FIRST PREV 1 2 3 4 5 NEXT LAST