National Advisory Committee for Aeronautics (NACA) - 744 Matching Results

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Wind-tunnel investigation of the effect of tab balance on tab and control-surface characteristics

Description: An investigation was conducted to furnish data on the effect of tab balance on tab and control-surface characteristics. The airfoil tested had a modified NACA 65(1)-012 contour with a plain flap having a chord equal to 25 percent of the wing chord and with a tab having a chord equal to 25 percent of the flap chord and having several nose shapes and overhang lengths. The results of the investigation indicated that, in general, tab balance affected tab hinge-moment characteristics in much the same manner that flap balance affects flap hinge-moment characteristics. A moderate amount of tab balance did not seem to have any adverse effect on flap hinge-moment characteristics.
Date: August 1947
Creator: Brewer, Jack D. & Queijo, M. J.
Partner: UNT Libraries Government Documents Department

NACA conference on Aerodynamic Problems of Transonic Airplane Design

Description: Compilation of the papers presented at a NACA conference on transonic airplane design, including stability and control and configurations with extreme sweep. From Introduction: "The purpose of this conference was to convey to those involved in the study of the aerodynamic problems of transonic aircraft these recent research results and to provide those attending an opportunity for discussion of the results."
Date: 1947-11-05/1947-11-06
Partner: UNT Libraries Government Documents Department

Introduction to the problem of rocket-powered aircraft performance

Description: An introduction to the problem of determining the fundamental limitations on the performance possibilities of rocket-powered aircraft is presented. Previous material on the subject is reviewed and given in condensed form along with supplementary analyses. Some of the problems discussed are: 1) limiting velocity of a rocket projectile; 2) limiting velocity of a rocket jet; 3) jet efficiency; 4) nozzle characteristics; 5) maximum attainable altitudes; 6) ranges. Formulas are presented relating the performance of a rocket-powered aircraft to basic weight and nozzle dimensional parameters. The use of these formulas is illustrated by their application to the special case of a nonlifting rocket projectile.
Date: December 1947
Creator: Ivey, H. Reese; Bowen, Edward N., Jr. & Oborny, Lester F.
Partner: UNT Libraries Government Documents Department

A method for calculating the heat required for windshield thermal ice prevention based on extensive flight tests in natural icing conditions

Description: Report presenting an equation for calculating the heat flow required from the surface of an internally heated windshield in order to prevent ice accretions during flight in specified icing conditions. Results regarding the internally heated windshield characteristics, external discharge windshields, and prediction of heating requirements for both types of windshields are provided.
Date: November 1947
Creator: Jones, Alun R.; Holdaway, George H. & Steinmetz, Charles P.
Partner: UNT Libraries Government Documents Department

A method for estimating heat requirements for ice prevention gas heated hollow propeller blades

Description: Report presenting a method for determining the temperature and flow of heated gas necessary for ice prevention of hollow propeller blades in flight and icing conditions. A variety of conditions are taken into consideration and suggested simplifications and short methods are provided in order to not overcomplicate the design modifications.
Date: December 1947
Creator: Gray, V. H. & Campbell, R. G.
Partner: UNT Libraries Government Documents Department

Elastic properties in tension and shear of high strength nonferrous metals and stainless steel - effect of previous deformation and heat treatment

Description: A resume is given of an investigation of the influence of plastic deformation and of annealing temperature on the tensile and shear elastic properties of high strength nonferrous metals and stainless steels in the form of rods and tubes. The data were obtained from earlier technical reports and notes, and from unpublished work in this investigation. There are also included data obtained from published and unpublished work performed on an independent investigation. The rod materials, namely, nickel, monel, inconel, copper, 13:2 Cr-Ni steel, and 18:8 Cr-Ni steel, were tested in tension; 18:8 Cr-Ni steel tubes were tested in shear, and nickel, monel, aluminum-monel, and Inconel tubes were tested in both tension and shear. There are first described experiments on the relationship between hysteresis and creep, as obtained with repeated cyclic stressing of annealed stainless steel specimens over a constant load range. These tests, which preceded the measurements of elastic properties, assisted in devising the loading time schedule used in such measurements. From corrected stress-set curves are derived the five proof stresses used as indices of elastic or yield strength. From corrected stress-strain curves are derived the secant modulus and its variation with stress. The relationship between the forms of the stress-set and stress-strain curves and the values of the properties derived is discussed. Curves of variation of proof stress and modulus with prior extension, as obtained with single rod specimens, consist in wavelike basic curves with superposed oscillations due to differences of rest interval and extension spacing; the effects of these differences are studied. Oscillations of proof stress and modulus are generally opposite in manner. The use of a series of tubular specimens corresponding to different amounts of prior extension of cold reduction gave curves almost devoid of oscillation since the effects of variation of rest interval and extension spacing ...
Date: March 1, 1947
Creator: Mebs, R W & Mcadam, D J
Partner: UNT Libraries Government Documents Department

Effects of sweepback on boundary layer and separation

Description: "Following the law of stress adopted in the Navier-Stokes equations, the configuration of the viscous flow in planes at right angles to the axis of an infinite cylinder is found to be independent of the axial motion of the cylinder. In the limiting case of a yawed or swept wing of very high aspect ratio, certain boundary-layer and separation phenomena are thus determined independently by the crosswise component of velocity" (p. 1).
Date: July 1947
Creator: Jones, Robert T.
Partner: UNT Libraries Government Documents Department

Investigation of NACA 65(sub 112) A111 (approx.) airfoil with 0.35-chord slotted flap at Reynolds numbers up to 25 million

Description: Report presenting an investigation in the two-dimensional low-turbulence tunnel and low-turbulence pressure tunnel to determine the highest maximum lift configurations of a slotted flap on an NACA 65(sub 112)A111 (approx.) airfoil section. The scale effects on aerodynamic characteristics were determined for a range of Reynolds numbers. Results regarding flap configurations, lift characteristics, pitching-moment characteristics, drag characteristics, and effects of leading-edge roughness are provided.
Date: October 1947
Creator: Racisz, Stanley F.
Partner: UNT Libraries Government Documents Department

Method of designing vaneless diffusers and experimental investigation of certain undetermined parameters

Description: Report presenting a method of designing vaneless diffusers using data given for simple conical diffusers. A family of diffusers with three different cone angles and the same throat height was designed and experimentally studied. A second set of diffusers with varying throats with the best cone angle was also investigated.
Date: September 1947
Creator: Brown, W. Byron & Bradshaw, Guy R.
Partner: UNT Libraries Government Documents Department

A method of calculating the compressive strength of Z-stiffened panels that develop local instability

Description: From Summary: "A method, based on the elastic theory for plate buckling and test results for 24S-T aluminum-alloy Z-stiffened panels, is shown for calculating the compressive strength of Z-stiffened panels that develop local instability. This method can be used to calculate the critical compressive stress above, as well as within, the elastic range. For stresses above three-fourths the compressive yield stress the method can be used for the approximate determination of the average compressive stress at maximum load."
Date: November 1947
Creator: Gallaher, George L. & Boughan, Rolla B.
Partner: UNT Libraries Government Documents Department