National Advisory Committee for Aeronautics (NACA) - 333 Matching Results

Search Results

Tail Buffeting

Description: An approximate theory of buffeting is here presented, based on the assumption of harmonic disturbing forces. Two cases of buffeting are considered: namely, for a tail angle of attack greater and less than the stalling angle, respectively. On the basis of the tests conducted and the results of foreign investigators, a general analysis is given of the nature of the forced vibrations the possible load limits on the tail, and the methods of elimination of buffeting.
Date: February 1, 1943
Creator: Abdrashitov, G.
Partner: UNT Libraries Government Documents Department

A subpress for compressive tests

Description: A subpress for compressive tests is described. The subpress was designed primarily for use in developing and investigating methods for testing thin sheet metal in compression. Provision was made for testing fixed-end and flat-end specimens with or without various types of lateral support against buckling. Compressive stress-strain data for a sheet of 0.032-inch 24S-RT aluminum alloy were obtained with the subpress by the pack method and by the single-thickness method. The data showed small scatter and the stress-strain curves obtained by the two methods were in close agreement.
Date: December 1, 1943
Creator: Aitchison, C S & Miller, James A
Partner: UNT Libraries Government Documents Department

A method for calculating heat transfer in the laminar flow region of bodies

Description: This report has been prepared to provide a practical method for determining the chordwise distribution of the rate of heat transfer from the surface of a wing or body of revolution to air. The method is limited in use to the determination of heat transfer from the forward section of such bodies when the flow is laminar. A comparison of the calculated average heat-transfer coefficient for the nose section of the wing of a Lockheed 12-A airplane with that experimentally determined shows a satisfactory agreement. A sample calculation is appended.
Date: 1943
Creator: Allen, H. Julian & Look, Bonne C.
Partner: UNT Libraries Government Documents Department

The Effect of Compressibility on the Growth of the Laminar Boundary Layer on Low-Drag Wings and Bodies

Description: The development of the laminar boundary layer in a compressible fluid is considered. Formulas are given for determining the boundary-layer thickness and the ratio of the boundary-layer Reynolds number to the body Reynolds number for airfoils and bodies of revolution. It i s shown that the effect of compressibility will profoundly alter the Reynolds number corresponding to the upper limit of the range of the low-drag coefficients . The available data indicate that for low-drag and high critical compressibility speed airfoils and bodies of revolution, this effect is favorable.
Date: January 1943
Creator: Allen, H. Julian & Nitzberg, Gerald E.
Partner: UNT Libraries Government Documents Department

Preliminary tests to determine the dynamic stability characteristics of various hydrofoil systems for seaplanes and surface boats

Description: Report discusses the results of testing on the dynamic stability characteristics of various hydrofoil systems for seaplanes, including a flat-hydrofoil tandem system, a 20 degree V-hydrofoil tandem system, a curved-hydrofoil tandem system, a flat-hydrofoil ladder system, a Guidoni S.V.A.-type hydrofoil on a streamline spindle, and several self-propelled models, including the Tietjens hydrofoil system. The instability and spray were compared for the different systems.
Date: November 1943
Creator: Benson, James M. & King, Douglas A.
Partner: UNT Libraries Government Documents Department

The use of a retractable planing flap instead of a fixed step on a seaplane

Description: Report presents and discusses the improvements in hydrodynamic and aerodynamic performance of a seaplane with a retractable planing flap instead of a conventional main step. A type of flap that could be used is described and tested for hydrodynamic stability. Results regarding the trim limits of stability, limiting positions of the center of gravity, and skipping are provided.
Date: May 1943
Creator: Benson, James M. & Lina, Lindsay J.
Partner: UNT Libraries Government Documents Department

Relation of preignition and knock to allowable engine temperatures

Description: From Summary: "The results are given of an investigation of some of the limitations that now prevent increases in the temperature level of engine cylinder heads, and a review of previous work in the field is included to supplement these results. Attention was given, in particular, to the effects of fuel knock and surface ignition on cylinder temperatures and the effects of cylinder temperatures on performance. Data were obtained from a Wright C9GC air-cooled cylinder and from a Lycoming O-1230 liquid-cooled cylinder."
Date: July 1943
Creator: Biermann, Arnold E. & Corrington, Lester C.
Partner: UNT Libraries Government Documents Department

Wind-tunnel tests of a piston-type control booster on an airfoil and aileron model

Description: From Summary: "Measurements of control moments were made in the NACA stability tunnel to determine the operational characteristics of a piston-type control booster on an aileron. The booster was so constructed and installed that pressures picked up from the air stream below the wing acted on a pair of pistons. The data are presented in the form of curves of pressure coefficients acting on the pistons, hinge-moment coefficients, and booster coefficients plotted against aileron deflection."
Date: November 1943
Creator: Bird, J. D. & Mendelsohn, Robert A.
Partner: UNT Libraries Government Documents Department