National Advisory Committee for Aeronautics (NACA) - 471 Matching Results

Search Results

The column strength of aluminum alloy 75S-T extruded shapes

Description: Because the tensile strength and tensile yield strength of alloy 75S-T are appreciably higher than those of the materials used in the tests leading to the use of the straight-line column curve, it appeared advisable to establish the curve of column strength by test rather than by extrapolation of relations determined empirically in the earlier tests. The object of this investigation was to determine the curve of column strength for extruded aluminum alloy 75S-T. In addition to three extruded shapes, a rolled-and-drawn round rod was included. Specimens of various lengths covering the range of effective slenderness ratios up to about 100 were tested.
Date: January 1, 1946
Creator: Holt, Marshall & Leary, J R
Partner: UNT Libraries Government Documents Department

Model tests of a wing-duct system for auxiliary air supply

Description: Report discusses the design of a cooling system developed for a Pratt & Whitney H-2800 engine equipped with a two-stage supercharger. The wing-duct system was newly developed and was determined to be a valuable method for cooling engine auxiliaries by combining simplicity with low drag and excellent cooling capabilities.
Date: January 1941
Creator: Bierman, David & Corson, Blake W., Jr.
Partner: UNT Libraries Government Documents Department

Flight measurements of the lateral and directional stability and control characteristics of an airplane having a 35 degree sweptback wing with 40-percent-span slots and a comparison with wind-tunnel data

Description: Report presenting flight tests conducted to determine the lateral and directional stability and control characteristics of an airplane on which the wing panels are swept back 35 degrees. The wings were equipped with slots extending from 40 to 80 percent of the span of the sweptback wing panels measured from the inboard end. Results regarding the steady sideslips, dynamic directional stability, rudder kicks, and aileron rolls are provided.
Date: January 1948
Creator: Sjoberg, S. A. & Reeder, J. P.
Partner: UNT Libraries Government Documents Department

Investigation of Meteorological Conditions Associated with Aircraft Icing in Layer-Type Clouds for 1947-48 Winter

Description: Rotating-cylinder measurements of the icing conditions encountered in flight during the winter of 1947-48 are presented. Liquid water content, drop size, and temperature data are shown to be consistent with previously measured conditions and with proposed maximum icing conditions in supercooled layer-type clouds. Cumulative frequency graphs of meteorological parameters indicate the frequency with which various icing conditions have been encountered in the Great Lakes area and surrounding states.
Date: January 1949
Creator: Kline, Dwight B.
Partner: UNT Libraries Government Documents Department

Performance tests of wire strain gages 6: effect of temperature on calibration factor and gage resistance

Description: Report presenting results of testing to determine the variation in calibration factor and gage resistance with temperature are presented for 15 types of single-element, multistrand wire strain gage. More than half of the gages tested were relatively insensitive to changes in temperature.
Date: January 1948
Creator: Campbell, William R.
Partner: UNT Libraries Government Documents Department

On the flying qualities of helicopters

Description: Report presenting the flying qualities problems of current helicopters, including instability with angle of attack in forward flight, control sensitivity in hovering, and control forces following control movement in maneuvers. Some possible solutions to these issues are presented.
Date: January 27, 1949
Creator: Reeder, John P. & Gustafson, F. B.
Partner: UNT Libraries Government Documents Department

Study by the Prandtl-Glauert method of compressibility effects and critical Mach number for ellipsoids of various aspect ratios and thickness ratios

Description: From Summary: "By the use of a form of the Prandtl-Glauert method that is valid for three-dimensional flow problems, the value of the maximum incremental velocity for compressible flow about thin ellipsoids at zero angle of attack is calculated as a function of the Mach number for various aspect ratios and thickness ratios. The critical Mach numbers (within the accuracy of the Prandtl-Glauert method) of the various ellipsoids are also determined. The results indicate an increase in critical Mach number with decrease in aspect ratio which is large enough to explain experimental results on low-aspect-ratio wings at zero lift."
Date: January 1949
Creator: Hess, Robert V. & Gardner, Clifford S.
Partner: UNT Libraries Government Documents Department

Comparison of over-all impact loads obtained during seaplane landing tests with loads predicted by hydrodynamic theory

Description: Report presenting a landing investigation with a flying boat with a conventional configuration to determine the applicability of hydrodynamic impact theory in defining full-scale water impact loads. The results indicated that in addition to chine flare and angular rotation, there are many other factors that may affect overall load, such as elasticity effects, sustained pressures on the area behind the chine, and the effect of variation of wing lift during impact.
Date: January 1949
Creator: Steiner, Margaret F.
Partner: UNT Libraries Government Documents Department

An investigation of the section characteristics of plain unsealed ailerons on an NACA 66,1-115 airfoil section in the Langley 8-foot high-speed tunnel

Description: Report presenting complete pressure-distributions measurements over a 24-inch-chord NACA 65,1-115 airfoil equipped with 20-percent-chord plain ailerons with aerodynamically smooth surfaces. Characteristics determined included airfoil normal-force, pitching-moment, aileron normal-force, and hinge-moment coefficients for a variety of Mach numbers, angles of attack, and aileron deflections. The aileron effectiveness parameter and section pitching-moment parameter are calculated.
Date: January 1949
Creator: Luoma, Arvo A.
Partner: UNT Libraries Government Documents Department

Critical stress of thin-walled cylinders in axial compression

Description: Empirical design curves are presented for the critical stress of thin-walled cylinders loaded in axial compression. These curves are plotted in terms of nondimensional parameters of small-deflection theory and are compared with theoretical curves derived for the buckling of cylinders with simply supported and clamped edges. An empirical equation is given for the buckling of cylinders having a length-radius ratio greater than about 0.75. The test data obtained from various sources follow the general trend of the theoretical curve for cylinders with clamped edges, agreeing closely with the theory in the case of short cylinders, but falling considerably below the theoretical results for long cylinders. The discrepancy in the case of long cylinders increases with increasing values of the ratio of radius to wall thickness. Plotting curves for different values of this ratio reduces the scatter in the test data and a certain degree of correlation with theory is achieved. Advantage is taken of this correlation to obtain estimated design curves for cylinders with simply supported edges, for which little experimental information is available. (author).
Date: January 1, 1947
Creator: Batdorf, S. B.; Shildcrout, Murry & Stein, Manuel
Partner: UNT Libraries Government Documents Department

A study of stall phenomena on a 45 degree swept-forward wing

Description: Report presenting an investigation to determine the underlying causes of the undesirable longitudinal characteristics of a 45 degree swept-forward wing in the moderate and high lift-coefficient range. Several methods were used to create a detailed correlation between separation phenomena and longitudinal characteristics of the wing. Both turbulent and leading-edge separation need to be postponed in order to improve the longitudinal characteristics of this wing.
Date: January 1949
Creator: McCormack, Gerald M. & Cook, Woodrow L.
Partner: UNT Libraries Government Documents Department

Experimental investigation of velocity distributions of downstream of single duct bends

Description: Report presenting measurements of the velocity distributions at the outlet of a large number of duct elbows of round and elliptical as well as square and rectangular cross section at a range of Reynolds numbers. Special investigations include measurements of the decay of velocity patterns produced by curved ducts and the effect of asymmetrical upstream velocity distributions. Results regarding typical distributions, tabulation of principal results, and special investigations are provided.
Date: January 13, 1947
Creator: Weske, John R.
Partner: UNT Libraries Government Documents Department

An investigation of aircraft heaters XXX : nocturnal irradiation as a function of altitude and its use in determination of heat requirements of aircraft

Description: Report presenting generalized radiation charts for the calculation of the irradiation from water vapor, carbon dioxide, ozone, and the earth in terms of appropriate parameters. Nocturnal irradiation was found to decrease greatly as a function of altitude and meteorological conditions.
Date: January 1949
Creator: Boelter, L. M. K.; Poppendiek, H.; Young, G. & Andersen, J. R.
Partner: UNT Libraries Government Documents Department