National Advisory Committee for Aeronautics (NACA) - 337 Matching Results

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A Simple Method of Estimating the Subsonic Lift and Damping in Roll of Sweptback Wings

Description: A method of modifying existing correction factors of lifting-surface theory to account approximately for the effects of sweep was derived, and these factors were applied to existing lifting-line theories for the lift and damping in roll of swept wings. Despite the simplicity of the resulting formulas the agreement with experimental data for low speeds is very good. The equation for lift is expressed entirely in terms of the geometric characteristics of the wing and the section-lift-curve; the necessity for any charts is thereby eliminated. The equation for the damping in roll, however, requires a chart for the determination of the effective lateral center of pressure for rolling moment due to rolling. If the Glauert-Prandtl transformation is used, the formulas obtained can be applied to swept wings at subsonic speeds below the critical speed.
Date: April 1949
Creator: Polhamus, Edward C.
Partner: UNT Libraries Government Documents Department

A review of instruments developed for the measurement of the meteorological factors conductive to aircraft icing

Description: Report presenting a review of the status of instruments suitable for the measurement of the meteorological factors conducive to aircraft icing. Nine instruments which appear to be the most promising for obtaining meteorological data are discussed and recommendations for their continued use and development are provided.
Date: April 26, 1949
Creator: Jones, Alun R. & Lewis, William
Partner: UNT Libraries Government Documents Department

Effect of aging on mechanical properties of aluminum-alloy rivets

Description: Curves and tabular data present the results of strength tests made during and after 2 1/2 years of aging on rivets and rivet wire of 3/16-inch nominal diameter. The specimens were of aluminum alloy: 24S, 17S, and A17S of the duralumin type and 53S of the magnesium-silicide type.
Date: April 1941
Creator: Roop, Frederick C
Partner: UNT Libraries Government Documents Department

AVA monographs. B: Boundary layer

Description: Report discusses several experiments regarding boundary layers and their influence on aircraft. The first experiment investigates how to best design airfoils. The second involves using suction to remove the boundary layer. The third involves surface disturbances and how they may affect the boundary layer.
Date: April 1, 1948
Creator: Holstein, H.; Bete, A. & Tollmein, W.
Partner: UNT Libraries Government Documents Department

Tests of a gust-alleviating wing in the gust tunnel

Description: "Tests were made in the NACA gust tunnel to determine the effectiveness of a torsionally flexible wing with the torsion axis ahead of the locus of the section aerodynamic centers in reducing airplane accelerations due to atmospheric gusts. For three gust shapes, a series of flights was made with the airplane model equipped with either a torsionally flexible or a rigid wing. The results indicated that the torsionally flexible wing reduced the maximum acceleration increment 5 percent for the sharp-edge gust and about 17 percent for gust shapes with gradient distances of 6.8 and 15 chord lengths" (p. 1).
Date: April 1941
Creator: Shufflebarger, C. C.
Partner: UNT Libraries Government Documents Department

Some effects of rainfall on flight of airplanes and on instrument indications

Description: "Several possible effects of heavy rain on the aerodynamic performance of an airplane and of heavy rain and associated atmospheric phenomena on the indications of flight instruments are briefly considered. It is concluded that the effects of heavy rain on the performance of an airplane are not so great as to force the airplane down from moderate altitudes. Serious malfunctioning of the air-speed indicator may occur, however, as a result of flooding of the pitot-static head and subsequent accumulation of water in the air-speed pressure line" (p. 1).
Date: April 1941
Creator: Rhode, Richard V.
Partner: UNT Libraries Government Documents Department

Free-space oscillating pressures near the tips of rotating propellers

Description: Report presenting the theory for calculating the free-space oscillating pressures associated with a rotating propeller at any point in space. Good agreement was found between analytical and experimental results using this method. Results regarding vibration and sound levels in the fuselage in relation to pressure level are reported.
Date: April 1949
Creator: Hubbard, Harvey H. & Regier, Arthur A.
Partner: UNT Libraries Government Documents Department

Further experiments on the flow and heat transfer in a heated turbulent air jet

Description: Measurements have been made of the mean total-head and temperature fields in a round turbulent jet with various initial temperatures. The results show that the jet spreads more rapidly as its density becomes lower than that of the receiving medium, even when the difference is not sufficiently great to cause measurable deviations from the constant-density, dimensionless, dynamic-pressure profile function. Rough analytical considerations have given the same relative spread. The effective "turbulent Prandtl number" for a section of the fully developed jet was found to be equal to the true (laminar) Prandtl number within the accuracy of measurement. (author).
Date: April 1, 1949
Creator: Corrsin, Stanley & Uberoi, Mahinder S
Partner: UNT Libraries Government Documents Department

Note on similarity conditions for flows with heat transfer

Description: Report presenting an examination of the conditions for similarity of flow for a compressible fluid with heat transfer with particular reference to variation of stagnation temperature and scale of the model. Important simplification of the experimental procedure for tests simulating flight at high Mach number is possible by using the similarity relations developed in the report.
Date: April 1948
Creator: von Doenhoff, Albert E.
Partner: UNT Libraries Government Documents Department

Simulated-altitude investigations of performance of tubular aircraft oil coolers

Description: Report presenting an investigation of the effects of altitude on the heat dissipation and on the oil pressure drop of an unjacketed and a conventional jacketed aircraft oil cooler at up to 40,000 feet. The investigation covered a variety of oil flows, cooling air flows, and oil-inlet temperatures.
Date: April 1948
Creator: Manson, S. V.
Partner: UNT Libraries Government Documents Department

A meteorological measure of maximum gust velocities in clouds

Description: Report presenting analytical considerations of the energy transformations in convective-type clouds indicate that a simple function of the height of convective activity and horizontal-temperature variations could yield a measure of the gustiness in clouds. A simplified relation that may be used to forecast the maximum effective gust velocities within convective-type clouds is developed. The analysis indicates that the method might be extended to almost all cloud types.
Date: April 1948
Creator: Gringorten, I. I. & Press, H.
Partner: UNT Libraries Government Documents Department

Wind-tunnel investigation of the boundary layer on an NACA 0009 airfoil having 0.25- and 0.50- airfoil chord plain sealed flaps

Description: Report presenting an investigation to determine the boundary-layer characteristics of an NACA 0009 airfoil equipped with 0.25- and 0.50-airfoil chord plain sealed flaps. The test objective was to define as thoroughly as possible the characteristics of two of the configurations used in a comprehensive investigation of control-surface characteristics and to provide additional data for comparison with previous boundary-layer analyses.
Date: April 1948
Creator: Brewer, Jack D. & Polhamus, Josephine F.
Partner: UNT Libraries Government Documents Department