National Advisory Committee for Aeronautics (NACA) - 276 Matching Results

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Accelerations in transport-airplane crashes

Description: From Introduction: "A study of crash-impact survival in light airplanes is reported in references 1 and 2. A similar study for fighter airplanes is reported in reference 3. This report discusses crash-impact survival in transport airplanes."
Date: February 1958
Creator: Preston, G Merritt & Pesman, Gerard J
Partner: UNT Libraries Government Documents Department

Acoustic, thrust, and drag characteristics of several full-scale noise suppressors for turbojet engines

Description: From Introduction: " Considerable analytical and experimental research has been done to find means of reducing the noise levels of the turbojet transports. Noise levels can be decreased by engine redesign to reduce the jet-exit velocity (ref. 1), proper flight-climb techniques (ref. 2), and the use of noise-suppression exhaust nozzles (refs. 3 to 5). The present report is concerned with the last method."
Date: April 1958
Creator: Ciepluch, Carl C; North, Warren J; Coles, Willard D & Antl, Robert J
Partner: UNT Libraries Government Documents Department

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.
Partner: UNT Libraries Government Documents Department

Analysis of harmonic forces produced at hub by imbalances in helicopter rotor blades

Description: From Introduction: "First, an analysis of loads transmitted to the hub by balanced blades will be given. In the second section, the additional loads transmitted to the hub in a direction normal to the plane of rotation of the blades by imbalances in a rotor are derived. In the entire analysis, the results are given in terms of the forces transmitted to the hub by a single rotating helicopter blade in flight, and these are regarded as known or given."
Date: April 1958
Creator: Morduchow, M & Muzyka, A
Partner: UNT Libraries Government Documents Department

An Analysis of Ramjet Engines Using Supersonic Combustion

Description: From Introduction: "The concept of supersonic combustion is by no means new, although little work appears to have been published on the subject. For example, an analysis of supersonic combustion to provide lift under a wing is given in reference 1. Reference 2 discusses applications to hypersonic ramjets being studied at the University of Michigan."
Date: September 1958
Creator: Weber, Richard J & Mackay, John S
Partner: UNT Libraries Government Documents Department

Analysis of the creep behavior of a square plate loaded in edge compression

Description: From Introduction: "In reference 1 results of creep tests and empirical method for predicting collapse times are presented for plates loaded in compression on two opposite edges and with the remaining edges unloaded and supported in V-groove fixtures. Other approximate methods for handling plates having types of edge support are suggested in reference 2; however, experimental verification for these methods is quite limited. In reference 3 an analysis based on small-deflection theory is made of the creep deflection of a simply supported plate composed of a linear viscoelastic material - that is, a material in which the stress and strain and their appropriate time derivatives are related in a linear fashion."
Date: September 1958
Creator: Mccomb, Harvey G , Jr
Partner: UNT Libraries Government Documents Department

Analysis of turbulent flow and heat transfer in noncircular passages

Description: From Introduction: "In reference 1, wall temperature distributions for turbulent flow in rectangular and triangular ducts were calculated by using experimental velocity distributions and average heat-transfer coefficients, together with assumed similarity of the wall heat-transfer and wall shear-stress variations; no attempt was made to calculate either the heat-transfer coefficients or the velocity and temperature distributions in the fluid field. Some calculations of velocity and shear-stress distributions in corners are reported in reference 2."
Date: September 1958
Creator: Deissler, Robert G & Taylor, Maynard F
Partner: UNT Libraries Government Documents Department

Analysis of turbulent flow and heat transfer on a flat plate at high Mach numbers with variable fluid properties

Description: From Introduction: "In the turbulent case, however, the results of the various analyses disagree markedly because of the different assumptions made by various authors. These analyses are reviewed in references 1 to 3. The analysis is extended to flow and heat transfer in a boundary layer at high Mach numbers in this paper. (Some preliminary results were presented in ref. 11.)"
Date: April 1958
Creator: Deissler, R G & Loeffler, A L , Jr
Partner: UNT Libraries Government Documents Department