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The Effects of Roughness at High Reynolds Numbers on the Lift and Drag Characteristics of Three Thick Airfoils

Description: "In connection with studies of airfoils applicable to large high-speed aircraft, the effects of roughness on three 22-percent-thick airfoils were investigated. The tests were made over a range of Reynolds number from about 6 to 26 x 10(exp 6) for the airfoils smooth and with roughness strips applied to the surfaces. The results indicated that for the roughened models the scale effect was generally favorable" (p. 1).
Date: August 1944
Creator: Abbott, Frank T., Jr. & Turner, Harold R., Jr.
open access

Wind-tunnel investigation of profile drag and lift of an intermediate wing section of the XP-51 airplane with beveled trailing-edge and contour ailerons

Description: Report presenting the results of flight investigations showing that a beveled trailing-edge aileron gives as low or a lower profile drag than a contour aileron. Section profile drag and lift coefficients with two different types of ailerons were obtained at 3 different Reynolds numbers.
Date: January 1943
Creator: Abbott, Frank T., Jr. & Underwood, William J.
open access

Interference effects of longitudinal flat plates on low-drag airfoils

Description: Three airfoils were tested with an intersecting flat plate normal to the span as a preliminary study of interference effects on airfoils. Small interference effects were noted on the first two airfoils, while larger effects were noted on the NACA 66,2-422 section, which had previously been shown to be unconservative with respect to separation. Airfoils known to be conservative should be used for inboard sections subject to nacelle and fuselage interference.
Date: November 1942
Creator: Abbott, Ira H.
open access

Pressure-Distribution Measurements of a Low-Drag Airfoil With Slotted Flap Submitted by Curtiss-Wright Corporation

Description: "Pressure-distribution measurements were made at the request of the Materiel Division, U.S. Army Air Corps, on a 24-inch-chord wooden model equipped with a slotted flap and submitted by the Curtiss-Wright Corporation. The tests were made in the Langley two-dimensional tunnel at a Reynolds number of about 5,600,000" (p. 1).
Date: December 1941
Creator: Abbott, Ira H.
open access

Pressure-Distribution Measurements of a Model of a Davis Wing Section with Fowler Flap Submitted by Consolidated Aircraft Corporation

Description: Wing pressure distribution diagrams for several angles of attack and flap deflections of 0 degrees, 20 degrees, and 40 degrees are presented. The normal force coefficients agree with lift coefficients obtained in previous test of the same model, except for the maximum lifts with flap deflection. Pressure distribution measurements were made at Reynolds Number of about 6,000,000.
Date: January 1942
Creator: Abbott, Ira H.
open access

Pressure-distribution measurements of two airfoil models with Fowler flaps submitted by Consolidated Aircraft Corporation as alternative wing sections of the XB-32 airplane

Description: Report presenting pressure distribution measurements on two 24-inch chord models equipped with Fowler flaps in the two-dimensional low-turbulence pressure tunnel. Results regarding pressure-distribution diagrams and normal-force and moment coefficients are provided.
Date: January 1942
Creator: Abbott, Ira H.
open access

Tests of four models representing intermediate sections of the XB-33 airplane including sections with slotted flap and ailerons

Description: Report presenting testing in the two-dimensional tunnel of four models submitted by the Glenn L. Martin Company as intermediate sections of the wing of the XB-33 airplane. Each airfoil model had different types of flaps or no flaps at all. Results regarding the lift and drag data, lift coefficients, effect of flap positions, aileron effects, drag coefficients, and hinge-moment coefficients are provided.
Date: June 1942
Creator: Abbott, Ira H.
open access

Tests of a Highly Cambered Low-Drag-Airfoil Section with a Lift-Control Flap, Special Report

Description: Tests were made in the NACA two-dimensional low turbulence pressure tunnel of a highly cambered low-drag airfoil (NACA 65,3-618) with a plain flap designed for lift control. The results indicate that such a combination offers attractive possibilities for obtaining low profile-drag coefficients over a wide range of lift coefficients without large reductions of critical speed.
Date: December 1942
Creator: Abbott, Ira H. & Miller, Ralph B.
open access

Lift and Drag Tests of Three Airfoil Models With Fowler Flaps Submitted by Consolidated Aircraft Corporation

Description: Report presenting lift and drag tests made in the two-dimensional tunnel of three airfoil models. The models represented intermediate sections on alternative wings of the XB-32 airplane and were equipped with 0.30 Fowler flaps. Results regarding the Davis model, the C.A.C. model, and low-drag model are provided.
Date: December 1941
Creator: Abbott, Ira H. & Turner, Harold R., Jr.
open access

Summary of Airfoil Data

Description: From Summary: "The historical development of NACA airfoils is briefly reviewed. New data are presented that permit the rapid calculation of the approximate pressure distributions for the older NACA four-digit and five-digit airfoils by the same methods used for the NACA 6-series airfoils. The general methods used to derive the basic thickness forms for NACA 6 and 7-series airfoils together with their corresponding pressure distributions are presented. Detail data necessary for the application o… more
Date: 1945
Creator: Abbott, Ira H.; von Doenhoff, Albert E. & Stivers, Louis S., Jr.
open access

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" (p. 1).
Date: February 1943
Creator: Abdrashitov, G.
open access

Electrodeposition research progress report

Description: This report contains a review of this work conducted by the Electrodeposition Group for the last six months. Pictures and a discussion of the method used to convert production solutions to postum to hydrofluoride acid solutions of postum are given. Attempts to plate postum in an inert atmosphere by remote control have been made. As yet no successful runs have been completed. Standardization of normal calomel electrodes by comparison to silver-silver chloride electrodes and to hydrogen electrode… more
Date: June 1, 1948
Creator: Abel, W.; Bell, R. & Neibel, C.
open access

LIQUID THERMAL DIFFUSION

Description: A revised and expanded version of NNES-DC-1. The liquid thermal diffusion method for the separation of isotopes is described. The discussion includes the experimental aspects of the method, description of equipment, and the theoretical aspects of the process as applied to the design, development, and performance criteria. A short history of the liquid thermal diffusion method from 1940 to 1945 is preserted along; with a survey of relevant literature prior to 1940. The remainder of the report is… more
Date: September 10, 1946
Creator: Abelson, P.H.; Rosen, N. & Hoover, J.I. eds.
open access

The Theory of a Free Jet of a Compressible Gas

Description: "In the present report the theory of free turbulence propagation and the boundary layer theory are developed for a plane-parallel free stream of a compressible fluid. In constructing the theory use was made of the turbulence hypothesis by Taylor (transport of vorticity) which gives best agreement with test results for problems involving heat transfer in free jets" (p. 1).
Date: March 1944
Creator: Abramovich, G. N.
open access

Metabolism and Distribution of Inhaled Plutonium in Rats

Description: From abstract: "Several different techniques were used to introduce tracer quantities of plutonium into the lungs of rats. When aerosols were produced by atomizing aqueous solutions of the nitrates it was found that approximately 20 per cent of the dose was absorbed and deposited in the skelton [sic] with tetra-, hexa-, and trivalent plutonium. Thus with these compounds, the lungs represent a more dangerous portal of entry than either oral (0.05 per cent) or intramuscular (13 per cent) administ… more
Date: October 29, 1946
Creator: Abrams, Richard; Siebert, H. C.; Potts, A. M.; Forker, L. L.; Greenberg, D.; Postel, A. et al.
open access

Quality of Columbia River water

Description: This report is a memorandum sent on January 27, 1943 concerning the quality of the water of Columbia River. Topics included: ph value, water temperatures, hardness, and dissolved carbon dioxide contents.
Date: January 27, 1943
Creator: Acken, M. F.
open access

Fission product studies with plant dissolver solutions: IX-Iodine, X-Arsenic. SE-PC No. 61

Description: In continuing studies to characterize and identify fission product activities formed in the piles and appearing in plant dissolver solutions work was done to determine whether or not long-lived isotopes of certain elements were present. Two of the elements in this category were iodine and arsenic. The iodine isotope of particular interest was I{sup 129}. Its tellurium parent has been identified but no daughter activity attributable to iodine has been observed. The arsenic activities of interest… more
Date: January 8, 1946
Creator: Acken, M. F.; Sullivan, W. H. & Leader, G. R.
open access

Natural Icing of an Axial-Flow Turbojet Engine in Flight for a Single Icing Condition

Description: Memorandum presenting an investigation in natural icing conditions to determine the effect of ice formations on the performance of an axial-flow turbojet engine. A description of the change over time in tail-pipe temperature, engine jet thrust, fuel flow, ice collection, and acceleration qualities are provided.
Date: August 12, 1948
Creator: Acker, Loren W.
open access

Preliminary Results of Natural Icing of an Axial-Flow Turbojet Engine

Description: Memorandum presenting a flight investigation in natural icing conditions to determine the effect of ice formations on the performance of an axial-flow turbojet engine. Tail-pipe temperature increased from 761 to 1065 degrees Fahrenheit and the jet thrust decreased from 1234 to 910 pounds during a period of 45 minutes in icing. No general conclusions can be reached from the data because the icing condition was relatively light.
Date: August 6, 1948
Creator: Acker, Loren W.
open access

Preliminary results of natural icing of an axial-flow turbojet engine

Description: Report presenting a flight investigation in natural icing conditions to determine the effect of ice formations on the performance of an axial-flow turbojet engine. Results regarding the tail-pipe temperature, engine jet thrust, and characteristics of ice formation are provided. No general conclusions can be reached from the data because the icing condition was relatively light.
Date: August 6, 1948
Creator: Acker, Loren W.
open access

Comparison of flight performance of AN-F-58 and AN-F-32 fuels in J35 turbojet engine

Description: Report presenting a flight investigation to determine the comparative performance of AN-F-58 and AN-F-32 fuels in a 4000-pound-thrust turbojet engine. The fuels were equivalent over the range of conditions investigated. Results regarding corrected net thrust, corrected jet-fuel consumption, variation of corrected tail-pipe temperature, combustor blow-out speeds, and visual observations of the jet exhaust are provided.
Date: April 7, 1949
Creator: Acker, Loren W. & Kleinknecht, Kenneth S.
open access

Flight Comparison of Performance and Cooling Characteristics of Exhaust-Ejector Installation with Exhaust-Collector-Ring Installation

Description: Flight and ground investigations have been made to compare an exhaust-ejector installation with a standard exhaust-collector-ring installation on air-cooled aircraft engines in a twin-engine airplane. The ground investigation allowed that, whereas the standard engine would have overheated above 600 horsepower, the engine with exhaust ejectors cooled at take-off operating conditions at zero ram. The exhaust ejectors provided as much cooling with cowl flaps closed as the conventional cowl flaps i… more
Date: February 14, 1947
Creator: Acker, Loren W. & Kleinknecht, Kenneth S.
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