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Aerodynamic characteristics of damping screens

Description: From Summary: "The experimental investigation of damping screens described herein was undertaken primarily to test theories of the effects of damping screens and to obtain information on the performance of screens in oblique flow. The characteristics investigated include the damping of longitudinal and lateral components of turbulence, the effect of screens on scale, the conditions for the production of turbulence and eddies by screens, and the damping of spatial variations of mean speed."
Date: January 1950
Creator: Schubauer, G B; Spangenberg, W G & Klebanoff, P S

Aerodynamic characteristics of several airfoils of low aspect ratio

Description: From Summary: "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."
Date: August 1935
Creator: Zimmerman, C H

The aerodynamic characteristics of six commonly used Airfoils over a large range of positive and negative angles of attack

Description: From Summary: "This paper presents the results of tests of six commonly used airfoils: the CYH, the N-22, the C-72, the Boeing 106, and the Gottingen 398. The lifts, drags, and pitching moments of the airfoils were measured through a large range of positive and negative angles of attack. The tests were made in the variable density wind tunnel of the National Advisory Committee for Aeronautics at a large Boeing 106, and the Gottingen 398 airfoils, the negative maximum lift coefficients were found to be approximately half the positive; but for the M-6 and the CYH, which have less effective values were, respectively, 0.8 and 0.6 of the positive values."
Date: November 1931
Creator: Anderson, Raymond F

Aerodynamic characteristics of three deep-step planing-tail flying-boat hulls and a transverse-step hull with extended afterbody

Description: From Summary: "An investigation was made to determine the aerodynamic characteristics in the presence of a wing of three-step planning-tail flying-boat hulls which differed only in the amount of step fairing. The purpose of comparison, tests were also made of a transverse-step hull with an extended afterbody."
Date: August 1952
Creator: Riebe, John M & Naeseth, Rodger L

The aerodynamic characteristics of three tapered airfoils tested in the variable density wind tunnel

Description: From Summary: "This report contains the lift, drag, and moment characteristics of tapered Clark Y, Gottingen 393, and USA 45 airfoils as obtained from tests made in the Variable Density Wind Tunnel of the NACA. The results are given at both low and high Reynolds Numbers to show scale effect and to provide data for use in airplane design."
Date: February 1931
Creator: Anderson, Raymond F

Aerodynamic coefficients for an oscillating airfoil with hinged flap, with tables for a Mach number of 0.7

Description: From Introduction: "The fundamental integral equation for the pressure distribution on an oscillating thin airfoil moving at subsonic speed has been derived by Possio in reference 1. Collocation procedures have been used by Possio, Frazer, and Skan, and others to obtain lift and moment on an oscillating first plate. An important contribution has been made by Dietze (see reference 2 and 3), who has developed an iterative procedure for numerical solution of Possio's integral equation."
Date: October 1950
Creator: Turner, M J & Rabinowitz, S

The aerodynamic design of high Mach number nozzles utilizing axisymmetric flow with application to a nozzle of square test section

Description: From Introduction: "A method for the design of three-dimensional nozzles based on axi-symmetric flow is presented in this paper. The design method presented in this paper is general; however, as an illustrative example of the design of a Mach number 10 nozzle with square test section is included."
Date: June 1952
Creator: Beckwith, Ivan E; Ridyard, Herbert W & Cromer, Nancy

The aerodynamic design of supersonic propellers from structural considerations

Description: From Summary: "The aerodynamic design of propellers from considerations of centrifugal force is presented. By applying a constant minimum value of thickness ratio from root to tip and allowing the distribution of required area to appear in the blade plan form, propellers with good efficiency are realized at high Mach numbers by the method of this paper."
Date: December 1952
Creator: Hammack, Jerome B

The aerodynamic drag of five models of side floats N.A.C.A. Models 51-E, 51-F, 51-G, 51-H, 51-J

Description: The drag of five models of side floats was measured in the N.A.C.A. 7- by 10-foot wind tunnel. The most promising method of reducing the drag of floats indicated by these tests is lowering the angle at which the floats are rigged. The addition of a step to a float does not always increase the drag in the flying range, floats with steps sometimes having lower drag than similar floats without steps. Making the bow chine no higher than necessary might result in a reduction in air drag because of the lower angle of pitch of the chines. Since side floats are used formally to obtain lateral stability when the seaplane is operating on the water at slow speeds or at rest, greater consideration can be given to factors affecting aerodynamic drag than is possible for other types of floats and hulls.
Date: December 1938
Creator: House, R O

The aerodynamic drag of flying-boat hull model as measured in the NACA 20-foot wind tunnel I.

Description: From Introduction: "The main purpose of this investigation is to make available to the designer useful information with regard to the aerodynamic drag of various types of flying-boat hull models. The present report is the first in a series covering investigation in this field. Through close cooperation between hydrodynamics and aerodynamics divisions it is hoped that results leading to improvements in hull design obtained."
Date: April 1935
Creator: Hartman, Edwin P

The aerodynamic effect of a retractable landing gear

Description: Tests were conducted in the N.A.C.A. full scale wind tunnel at the request of the Army Air Corps to determine the effect of retractable landing gear openings in the bottom surface of a wing upon the characteristics of a Lockheed Altair airplane. The tests were extended to include the determination of the lift and drag characteristics throughout the angle-of-attack range with the landing gear both retracted and extended. Covering the wheel openings in the wing with sheet metal when the wheels were extended reduced the drag only 2 percent at a lift coefficient of 1.0, which was assumed for the take-off condition. Therefore, the wheel openings in the bottom side of the wing have a negligible effect upon the take-off of the airplane. Retracting the landing gear reduced the minimum drag of the complete airplane 50 percent.
Date: March 1933
Creator: Defrance, Smith J

Aerodynamic Effects Caused by Icing of an Unswept NACA 65A004 Airfoil

Description: The effects of ice formations on the section lift, drag, and pitching-moment coefficients of an unswept NACA 65A004 airfoil section of 6-foot chord were studied.. The magnitude of the aerodynamic penalties was primarily a function of the shape and size of the ice formation near the leading edge of the airfoil. The exact size and shape of the ice formations were determined photographically and found to be complex functions of the operating and icing conditions. In general, icing of the airfoil at angles of attack less than 40 caused large increases in section drag coefficients (as much as 350 percent in 8 minutes of heavy glaze icing), reductions in section lift coefficients (up to 13 percent), and changes in the pitching-moment coefficient from diving toward climbing moments. At angles of attack greater than 40 the aerodynamic characteristics depended mainly on the ice type. The section drag coefficients generally were reduced by the addition of rime ice (by as much as 45 percent in 8 minutes of icing). In glaze icing, however, the drag increased at these angles of attack. The section lift coefficients were variably affected by rime-ice formations; however, in glaze icing, lift increases at high angles of attack amounted to as much as 9 percent for an icing time of 8 minutes. Pitching-moment-coefficient changes in icing conditions were somewhat erratic and depended on the icing condition. Rotation of the iced airfoil to angles of attack other than that at which icing occurred caused sufficiently large changes in the pitching-moment coefficient that, in flight, rapid corrections in trim might be required in order to avoid a hazardous situation.
Date: February 1958
Creator: Gray, Vernon H. & vonGlahn, Uwe H.

Aerodynamic effects of a split flap on the spinning characteristics of a monoplane model

Description: From Summary: "The investigation described in this report was made to determine the change in aerodynamic forces and moments produced by split flaps in a steady spin. The test were made with the spinning balance in the NACA 5-foot vertical wind tunnel. A low-wing monoplane model was tested with and without the split flaps in 12 spinning attitudes chosen to cover the probable spinning range. The results obtained indicate that the use of split flaps on an airplane is unlikely, in any case, to have much beneficial effect on a spin, and it might make the spin dangerous."
Date: December 1934
Creator: Bamber, M J

The aerodynamic forces and moments on a 1/10-scale model of a fighter airplane in spinning attitudes as measured on a rotary balance in the Langley 20-foot free-spinning tunnel

Description: From Introduction: "This investigation provides general information on the magnitudes and directions of the aerodynamic forces and moments acting on a fighter airplane in fully developed spins. The investigation includes the determination of the effects on the aerodynamic forces and moments of varied rudder setting with and against the spin, of tail modifications, and of deflected flaps and lowered landing gear."
Date: September 1950
Creator: Stone, Ralph W , Jr; Burk, Sanger M , Jr & Bihrle, William, Jr