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A Thermal System for Continuous Monitoring of Laminar and Turbulent Boundary-Layer Flows During Routine Flight

Description: Note presenting a thermal system which could be used to determine whether the boundary layer on a wing in flight is turbulent or laminar. Tests were made using this system in the low-turbulence pressure tunnel.
Date: September 1957
Creator: Richardson, Norman R. & Horton, Elmer A.
Partner: UNT Libraries Government Documents Department

Turbulent Boundary Layer of an Airfoil

Description: A need has arisen for a new determination of the velocity profiles in the boundary layer. Assuming that the character of the velocity distribution depends to a large extent on the character of the shear distribution across the boundary layer, we shall consider the nature of the shear distribution for a boundary layer with a pressure gradient.
Date: April 1937
Creator: Fediaevsky, K.
Partner: UNT Libraries Government Documents Department

An integral solution to the flat-plate laminar boundary-layer flow existing inside and after expansion waves and after shock waves moving into quiescent fluid with particular application to the complete shock-tube flow

Description: Report presenting a solution to the unsteady two-dimensional laminar boundary-layer flow inside centered expansion waves and behind both centered expansion waves and shock waves using an extension of the Karman-Pohlhausen method. The Prandtl unsteady-boundary-layer equations are also integrated normal to the surface bounding the flow and are transformed into a conical coordinate system. The solution to the two-dimensional unsteady laminar boundary layer existing at all points in an air-air shock tube is obtained using the method.
Date: June 1957
Creator: Trimpi, Robert L. & Cohen, Nathaniel B.
Partner: UNT Libraries Government Documents Department

Boundary Layer

Description: From Introduction: "The fundamental, practically the most important branch of the modern mechanics of a viscous fluid or a gas, is that branch which concerns itself with the study of the boundary layer. The presence of a boundary layer accounts for the origin of the resistance and lift force, the breakdown of the smooth flow about bodies, and other phenomena that are associated with the motion of a body in a real fluid. The concept of boundary layer was clearly formulated by the founder of aerodynamics, N. E. Joukowsky, in his well-known work "On the Form of Ships" published as early as 1890."
Date: May 1956
Creator: Loitsianskii, L. G.
Partner: UNT Libraries Government Documents Department

Tables of exact laminar-boundary-layer solutions when the wall is porous and fluid properties are variable

Description: Report presenting the three partial differential equations of the laminar boundary layer for two-dimensional steady-state compressible flow, which have been transformed into two ordinary differential equations by the method of Pohlhausen, Falkner, and Skan. A total of 58 cases have been solved numerically by the method of Picard. For each of the cases, the displacement, momentum, and convection thicknesses, as well as Nusselt number and coefficient of friction at the wall, were computed.
Date: September 1951
Creator: Brown, W. Byron & Donoughe, Patrick L.
Partner: UNT Libraries Government Documents Department

Analytic determination of the discharge coefficients of flow nozzles

Description: From Introduction: "In rounded-approach nozzles with discharge coefficients close to unity, the frictional effects are concentrated in the boundary layer. A method of obtaining an analytical relation among the discharge coefficient, Reynolds number, and the nozzle geometry by utilization of elementary boundary-layer theory is presented herein."
Date: April 1955
Creator: Simmons, Frederick S.
Partner: UNT Libraries Government Documents Department

An evaluation of four experimental methods for measuring mean properties of a supersonic turbulent boundary layer

Description: Report presenting surveys made through a turbulent boundary layer on a flat plate by means of a pitot probe, an X-ray densitometer, and hot-wire and cold-wire probes. Results were analyzed to determine the reliability of basic data and how well the distributions of properties in the boundary layer compare with those assumed in theoretical analyses.
Date: June 1956
Creator: Nothwang, George J.
Partner: UNT Libraries Government Documents Department

An evaluation of four experimental methods for measuring mean properties of a supersonic turbulent boundary layer

Description: From Summary: "Surveys were made through a turbulent boundary layer on a flat plate by means of a pitot probe, an x-ray densitometer, and hot-wire and cold-wire probes. Results from these surveys were analyzed to determine (a) the reliability of the basic data and hence the methods by which they were obtained, and (b) how well the actual distributions of properties in the boundary layer compare with those commonly assumed in semiempirical and theoretical analyses. All surveys were made at the same longitudinal station on the flat plate. The tests were conducted in a an 8- by 8-inch supersonic nozzle. The free-stream Mach number was 3.03 and the Reynolds number was approximately 210,000 based on boundary-layer thickness."
Date: April 19, 1956
Creator: Nothwang, George J.
Partner: UNT Libraries Government Documents Department

Application of supersonic vortex-flow theory to the design of supersonic impulse compressor- or turbine-blade sections

Description: From Introduction: "The purpose of this paper is to present an analytical method for the design of two-dimensional related selection of a blade for particular rotor conditions may be made quickly and easily and its performance deduced from tests of representative sections in cascade."
Date: April 24, 1952
Creator: Boxer, Emanuel; Sterrett, James R. & Wlodarski, John
Partner: UNT Libraries Government Documents Department

An investigation of supersonic turbulent boundary layers on slender bodies of revolution in free flight by use of a Mach-Zehnder interferometer and shadowgraphs

Description: Report presenting a study of slender bodies of revolution in free flight at Mach numbers 3.2 and 3.6, which were photographed and analyzed to obtain the turbulent-boundary-layer density distributions for the case of a body surface that is cold compared to recovery temperature. Results regarding density profiles, density distributions, comparison with the Crocco equation, calculation of the heat-transfer rate, and observations of the turbulent-boundary-layer image structure from shadowgraphs, and relation the interferometer results are provided.
Date: September 1958
Creator: Seiff, Alvin & Short, Barbara J.
Partner: UNT Libraries Government Documents Department

Analysis of particle motions for a class of three-dimensional incompressible laminar boundary layers

Description: From Introduction: "Results obtained in the experimental investigations of secondary flows in turbomachines (refs. 1 to 3) indicate that information concerning three-dimensional laminar boundary-layer behavior can be of practical value in interpreting and correlating measurements of losses in the turbo-machines for design purposes. Reference 4 gives a theoretical analysis of the overturning (more than mainstream turning) of the three-dimensional laminar boundary layer developed on flat or nearly flat surfaces, under mainstream flows which consist of streamline translates (i.e., the entire streamline pattern can be obtained by translating any particular streamline pattern can be obtained by translating any particular streamline parallel to the leading edge, fig. 1) with constant axial velocity component."
Date: November 1956
Creator: Hansen, Arthur G. & Herzig, Howard Z.
Partner: UNT Libraries Government Documents Department

Boundary Layer Theory, Part 2, Turbulent Flows

Description: From Summary: "The flow laws of the actual flows at high Reynolds numbers differ considerably from those of the laminar flows treated in the preceding part. These actual flows show a special characteristic, denoted as turbulence. The character of a turbulent flow is most easily understood the case of the pipe flow. Consider the flow through a straight pipe of circular cross section and with a smooth wall. For laminar flow each fluid particle moves with uniform velocity along a rectilinear path."
Date: April 1949
Creator: Schlichting, H.
Partner: UNT Libraries Government Documents Department

Exact solutions of laminar-boundary-layer equations with constant property values for porous wall with variable temperature

Description: From Summary: "Exact solution of the laminar-boundary-layer equations for wedge-type flow with constant property values are presented for transpiration-cooled surfaces with variable wall temperatures. The difference between wall and stream temperature is assumed proportional to a power of the distance from the leading edge. Solutions are given for a Prandtl number of 0.7 and ranges of pressure-gradient, cooling-air-flow, and wall-temperature-gradient parameters. Boundary-layer profiles, dimensionless boundary-layer thicknesses, and convective heat-transfer coefficients are given in both tabular and graphical form. Corresponding results for constant wall temperature and for impermeable surfaces are included for comparison purposes."
Date: July 15, 1954
Creator: Donoughe, Patrick L. & Livingood, John N. B.
Partner: UNT Libraries Government Documents Department

An experimental study of the turbulent boundary layer on a shock-tube wall

Description: From Summary: "Interferometric measurements were made of the density profiles of an unsteady turbulent boundary layer on the flat wall of a shock tube. The investigation included both subsonic and supersonic flow (Mach numbers of 0.50 and 1.77) with no pressure gradient and with heat transfer to a cold wall. Velocity profiles and average skin-friction coefficients were calculated. Effects on the velocity profile of surface roughness and flow lengths are examined."
Date: June 1958
Creator: Gooderum, Paul B.
Partner: UNT Libraries Government Documents Department

Effect of thermal properties on laminar-boundary-layer characteristics

Description: Report presenting an iteration method for solving the laminar-boundary-layer equations for compressible flow in the absence of a pressure gradient when the temperature variation of all the fluid thermal properties is considered. Results in regard to skin friction and heat-transfer characteristics are provided.
Date: March 1953
Creator: Klunker, E. B. & McLean, F. Edward
Partner: UNT Libraries Government Documents Department

An analysis of the turbulent boundary-layer characteristics on a flat plate with distributed light-gas injection

Description: From Introduction: "The present paper is concerned with a transpiration cooling system in which the coolant passes through the surface it is protecting before entering the surrounding boundary layer. Analyses and experiments have been performed to determine the effect of distributed air transportation through flat surfaces over which air flows in turbulent boundary layer (refs. 2, 3, and 4)."
Date: February 1958
Creator: Rubesin, Morris W. & Pappas, Constantine C.
Partner: UNT Libraries Government Documents Department

Simplified method for calculation of compressible laminar boundary with arbitrary free-stream pressure gradient

Description: Report presenting a simplification of the Karman-Polhausen integral method as applied to compressible laminar boundary layers. The analysis was conducted under the assumptions of a Prandtl number of 1, zero heat transfer, and a linear viscosity-temperature relation.
Date: October 1951
Creator: Low, George M.
Partner: UNT Libraries Government Documents Department

An Analysis of the Effect of Structural Feedback on the Flutter of a Control Surface Having a Power-Boost System

Description: From Summary: "Such devices as leading- and trailing-edge flaps which are now in use on operational aircraft permit the attainment of maximum airplane lift coefficients, power-off, of the order of 2.8 (reference 1). Airfoil-section maximum lift coefficients as high as 5.5 have been obtained in wind-tunnel tests (see, for example, reference 2), and in a limited flight investigation airplane lift coefficients of 4.2 were obtained (reference 3)."
Date: June 10, 1952
Creator: Barnes, Robert H.
Partner: UNT Libraries Government Documents Department

Air Flow in the Boundary Layer of an Elliptic Cylinder

Description: From Introduction: "The present investigation was carried out for the purpose of supplementing the earlier work with information on the boundary layer under such conditions of air speed and turbulence that transition occurs and the layer is partly laminar and partly turbulent. In the work reported in reference 1, the air speed was about 12 feet per second, and it was assumed that the boundary layer remained in the laminar condition until after separation because the separation point remained fixed and the pressure distribution about the cylinder was unaffected until an air speed of 15 feet per second was reached."
Date: August 6, 1938
Creator: Schubauer, G. B.
Partner: UNT Libraries Government Documents Department

Determination of general relations for the behavior of turbulent boundary layers

Description: From Summary: "An analysis has been made of a considerable amount of data for turbulent boundary layers along wings and bodies of various shapes in order to determine the fundamental variables that control the development of turbulent boundary layers. It was found that the type of velocity distribution in the boundary layer could be expressed in terms of a single parameter. This parameter was chosen as the ratio of the displacement thickness to the momentum thickness of the boundary layer. The variables that control the development of the turbulent boundary layer apparently are: (1) the ratio of the nondimensional pressure gradient, expressed in terms of the local dynamic pressure outside the boundary layer and boundary-layer thickness, to the local skin-friction coefficient and (2) the shape of the boundary layer. An empirical equation has been developed in terms of these variables that, when used with the momentum equation and the skin-friction relation, makes it possible to trace the development of the turbulent boundary layer to the separation point."
Date: April 13, 1943
Creator: von Doenhoff, Albert E. & Tetervin, Neal
Partner: UNT Libraries Government Documents Department

Air flow in the boundary layer near a plate

Description: From Summary: "The published data on the distribution of speed near a thin flat plate with sharp leading edge placed parallel to the flow (skin friction plate) are reviewed and the results of some additional measurements are described. The purpose of the experiments was to study the basic phenomena of boundary-layer flow under simple conditions."
Date: March 1936
Creator: Dryden, Hugh L.
Partner: UNT Libraries Government Documents Department

Air flow in a separating laminar boundary layer

Description: Report discussing the speed distribution in a laminar boundary layer on the surface of an elliptic cylinder, of major and minor axes 11.78 and 3.98 inches, respectively, has been determined by means of a hot-wire anemometer. The direction of the impinging air stream was parallel to the major axis. Special attention was given to the region of separation and to the exact location of the point of separation. An approximate method, developed by K. Pohlhausen for computing the speed distribution, the thickness of the layer, and the point of separation, is described in detail; and speed-distribution curves calculated by this method are presented for comparison with experiment.
Date: December 1, 1934
Creator: Schubauer, G. B.
Partner: UNT Libraries Government Documents Department