National Advisory Committee for Aeronautics (NACA) - 13,806 Matching Results

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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

Application of the Method of Coordinate Perturbation to Unsteady Duct Flow

Description: The method of coordinate perturbation is applied to the unsteady flow of a compressible fluid in ducts of variable cross section. Solutions, in the form of perturbation series, are obtained for unsteady flows in ducts for which the logarithmic derivative of area variation with respect to the space coordinate is a function of the 'smallness' parameter of the perturbation series. This technique is applied to the problem of the interaction of a disturbance and a shock wave in a diffuser flow. It is found that, for a special choice of the function describing the disturbance, the path of the shock wave can be expressed in closed form to first order. The method is then applied to the determination of the flow field behind a shock wave moving on a prescribed path in the x,t-plane. Perturbation series solutions for quite general paths are developed. The perturbation series solutions are compared with the more exact solutions obtained by the application of the method of characteristics. The approximate solutions are shown to be in reasonably accurate agreement with the solutions obtained by the method of characteristics.
Date: September 1958
Creator: Himmel, Seymour C.
Partner: UNT Libraries Government Documents Department

The effect of free-stream turbulence on heat transfer from a flat plate

Description: Turbulence was generated by using screens, and the turbulence percentage was measured by a hot-wire anemometer both in the boundary layer and the free stream. The local heat-transfer coefficient was measured at 12 locations along the plate for the cases of various turbulence levels. The transition Reynolds number from laminar to turbulent flow decreases as the main-stream turbulence level increases. In the range of laminar heat transfer the effect of turbulence in the main flow was not great, but in the range of turbulent heat transfer the heat-transfer coefficient increases according to the increase of turbulence.
Date: September 1, 1958
Creator: Sugawara, Sugao; Sato, Takashi; Komatsu, Hiroyasu & Osaka, Hiroichi
Partner: UNT Libraries Government Documents Department

Effects of nose angle and Mach number on transition on cones at supersonic speeds

Description: An investigation has been made to determine the transition characteristics of a group of smooth, sharp-nosed cones varying from 10 degrees to sixty degrees in included apex angle over a Mach number range from 1.61 to 2.20 and a range of Reynolds number per foot from about 1.5 x 10 to the 6th power to 8 x 10 to the 6th power. Increasing the cone angle is shown to decrease slightly the transition Reynolds number, whereas the effects of changes of Mach number and unit Reynolds number are negligible. When transition occurred within 15 to 20 percent of the model length from the base there was a dropoff in transition Reynolds number. (author).
Date: September 1, 1958
Creator: Czarnecki, K R & Jackson, Mary W
Partner: UNT Libraries Government Documents Department