UNT Libraries Government Documents Department - 14 Matching Results

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A General Integral Form of the Boundary-Layer Equation for Incompressible Flow With an Application to the Calculation of the Separation Point of Turbulent Boundary Layers

Description: "A general integral form of the boundary-layer equation, valid for either laminar or turbulent incompressible boundary-layer flow, is derived. By using the experimental finding that all velocity profiles of the turbulent boundary layer form essentially a single-parameter family, the general equation is changed to an equation for the space rate of change of the velocity-profile shape parameter. The lack of precise knowledge concerning the surface shear and the distribution of the shearing stress across turbulent boundary layers prevented the attainment of a reliable method for calculating the behavior of turbulent boundary layers" (p. 1067).
Date: May 22, 1950
Creator: Tetervin, Neal & Lin, Chia Chiao

High-speed aerodynamic characteristics of a lateral-control model 3: section characteristics, fence studies, and tabulated pressure coefficients with modified NACA 0012-64 section, 26.6-percent-chord, plain aileron, 0 and 45 degree sweepback

Description: Report presenting wind-tunnel measurements of the pressure distribution on a semispan wing with a modified NACA 0012-64 airfoil section and a plain trailing-edge aileron with the wing unswept and also swept back 45 degrees. Adverse changes in loading and loss of aileron effectiveness developed with the wing unswept as the Mach number was increased, but did not occur at Mach numbers up to 0.925 with the swept wing. Results regarding section characteristics and effect of fences are provided.
Date: November 22, 1950
Creator: Krumm, Walter J. & Cleary, Joseph W.

Interpretation of boundary-layer pressure-rake data in flow with a detached shock

Description: From Summary: "A procedure is presented for determining boundary-layer quantities from pressure-rake data, which include the combined effects of viscous and shock losses. The problem is analyzed using schileren photographs of the shock configuration, the continuity of mass relationship, and the characteristic of the turbulent boundary layer that its outer edge is defined by a rapid change in slope in the Mach number profiles in the vicinity of the edge."
Date: December 22, 1950
Creator: Luidens, Roger W. & Madden, Robert T.

Investigation of altitude ignition, acceleration, and steady-state operation with a single combustor of a J47 turbojet engine

Description: From Summary :"An investigation was conducted with a single combustor from a J47 turbojet engine using weathered aviation gasoline and several spark-plug modifications to determine altitude ignition, acceleration, and steady state operating characteristics. Satisfactory ignition was obtained with two modifications of the original opposite-polarity spark plug up to and including an altitude of 40,003 feet at conditions simulating equilibrium windmilling of the engine at a flight speed of 400 miles per hour. At a simulated altitude of 30,000 feet, satisfactory ignition was obtained over a range of simulated engine speeds."
Date: September 22, 1950
Creator: Cook, William P. & Butze, Helmut F.

Investigation of Performance of Axial-Flow Compressor of XT-46 Turbine-Propeller Engine 1 - Preliminary Investigation at 50-,70-, and 100-Percent Design Equivalent Speed

Description: From Summary: "An investigation is being conducted to determine the performance of the 12-stage axial-flow compressor of the XT-46 turbine-propeller engine. This compressor was designed to produce a pressure ratio of 9 at an adiabatic efficiency of 0.86. The design pressure ratios per stage were considerably greater than any employed in current aircraft gas-turbine engines using this type of compressor. The compressor performance was evaluated at two stations."
Date: May 22, 1950
Creator: Creagh, John W. R. & Sandercock, Donald M.

Investigation of stage performance of X24C-2 ten-stage axial-flow compressor at design speed

Description: The stage performance of the X24C-2 axial-flow compressor, as determined from radial distributions of total pressure and temperature measured in each stator-blade row, was investigated at design speed at weight flows corresponding to those of the maximum weight-flow, peak-efficiency, and surge points. The stage performance is presented as the measured stage pressure ratios and the calculated velocity diagrams. The average stage total-pressure ratio at the surge operating condition in the first stage was approximately 1.10; in the second stage, approximately 1.13; and in all remaining stages, approximately constant at a value of 1.15. Regions of inefficient flow are discussed so as to point out the reasons for the poor flow conditions.
Date: May 22, 1950
Creator: Finger, Harold B.; Cohen, Leo & Stewart, Warner L.

A Preliminary Experimental and Analytical Evaluation of Diborane as a Ram-Jet Fuel

Description: Report presenting an analytical and experimental evaluation of diborane as a ram-jet fuel, which seems to offer greater flight range, thrust, and combustion stability beyond what is attainable with petroleum fuels. Results regarding ideal thrust, stability, deposits, and flight range with several blends of diborane are provided.
Date: December 22, 1950
Creator: Gammon, Benson E.; Genco, Russell S. & Gerstein, Melvin

The Preparation of Thin Films of Plutonium by Electrodeposition

Description: This report discusses methods for preparing thin films of plutonium on metallic disks, which are used for alpha energy analysis, fission counting, and preparation of geometry standards in ordinary counting. Various methods of preparation were tested and analyzed, but electrodeposition was the most effective method. Deposition was then tested, but the yields were "somewhat erratic".
Date: March 22, 1950
Creator: Miller, H. W. & Brouns, R. J.

Pressure Distributions on the Blade Sections of the NACA 10-(3)(090)-03 Propeller Under Operating Conditions

Description: The third report in a series of five that present unanalyzed pressure data obtained in tests of five full-scale propellers with NACA 16-series blade sections. Pressure distributions on the blade sections were measured under operating conditions to determine the aerodynamic characteristics of each blade section. This particular report presents information for nine radial stations of the NACA 10-(3)(090)-03 propeller.
Date: March 22, 1950
Creator: Johnson, Peter J.

Theoretical symmetric span loading due to flap deflection for wings of arbitrary plan form at subsonic speeds

Description: From Summary: "A simplified lifting-surface theory is applied to the problem of evaluating span loading due to flap deflection for arbitrary wing plan forms. With the resulting procedure, the effects of flap deflection on the span loading and associated aerodynamic characteristics can be easily computed for any wing which is symmetrical about the root chord and which has a straight quarter-chord line over the wing semispan. The effects of compressibility and spanwise variation of section lift-curve slope are taken into account by the procedure. The method presented can also be used to calculate the downwash in the vertical center of the wake of a wing which has arbitrary spanwise loading."
Date: September 22, 1950
Creator: DeYoung, John

The Use of Area Suction for the Purpose of Delaying Separation of Air Flow at the Leading Edge of a 63 Degree Swept-Back Wing

Description: "An investigation was conducted to determine the effectiveness of area suction used to delay the separation of air flow at the leading edge of a 63 degree swept-back wing. Changes in lift, drag, and pitching-moment data were correlated with the occurrence of the separation of the air flow by means of pressure-distribution data. It was found that the spanwise and the chordwise extent of area suction required to control leading-edge separation were in general agreement with that predicted by theory, but the quantity of flow required was considerably higher than predicted by theory" (p. 1).
Date: November 22, 1950
Creator: Cook, Woodrow L.; Griffin, Roy N., Jr. & McCormack, Gerald M.

Wind-tunnel tests of a 0.16-scale model of the X-3 airplane at high subsonic speeds: wing and fuselage pressure distribution

Description: Report presenting measurements of wing and fuselage pressure distributions made at low and high subsonic Mach numbers on a scale model of the projected X-3 research airplane. Tests were conducted in pitch and yaw and included measurements of the total pressure in the fuselage boundary layer at the location of the left boundary-layer bleed scoop.
Date: June 22, 1950
Creator: Cleary, Joseph W. & Mellenthin, Jack A.