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Comparison of Three Exit-Area Control Devices on an N.A.C.A. Cowling, Special Report

Description: "Adjustable cowling flaps, an adjustable-length cowling skirt, and a bottom opening with adjustable flap were tested as means of controlling the rate of cooling-air flow through an air-cooled radial-engine cowling. The devices were tested in the NACA 20-foot tunnel on a model wing-nacelle-propeller combination, through an airspeed range of 20 to 80 miles per hour, and with the propeller blade angle set 23 degrees at 0.75 of the tip radius. The resistance of the engine to air flow through the co… more
Date: May 1940
Creator: McHugh, James G.
Partner: UNT Libraries Government Documents Department
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Consideration of Auxiliary Jet Propulsion for Assisting Take-Off

Description: Report presenting an analysis and simple method to help solve the problem of assisting the take-off of an airplane by means of auxiliary jet propulsion by determining the jet thrust and weight of jet fuel required to provide a desired reduction in take-off distance or increase in pay load or fuel load for a fixed take-off distance. The use of previous experimental work to verify the analysis is also provided.
Date: May 1940
Creator: Turner, L. Richard
Partner: UNT Libraries Government Documents Department
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The Flow of a Compressible Fluid Past a Sphere

Description: "The flow of a compressible fluid past a sphere fixed in a uniform stream is calculated to the third order of approximation by means of the Janzen-Rayleigh method. The velocity and the pressure distribution over the surface of the sphere are computed and the terms involving the fourth power of the Mach number, neglected in Rayleigh's calculation, are shown to be of considerable importance as the local velocity of sound is approached on the sphere. The critical Mach number, that is, the value of… more
Date: May 1940
Creator: Kaplan, Carl
Partner: UNT Libraries Government Documents Department
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On the Theory of Unsteady Planing and the Motion of a Wing With Vortex Separation

Description: The disturbance imparted to water by a planing body give rise to a wave form of motion on the free surface, the length of the waves increasing indefinitely with increase in the Froude number and being directly proportional to the latter in the case of the plane or two-dimensional problem. At large Froude numbers the effect of the weight shows up to any appreciable extent only at some distance from the body, so that the flow near the body can be considered as part of a flow of an infinitely exte… more
Date: May 1940
Creator: Sedov, L.
Partner: UNT Libraries Government Documents Department
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Pressure-distribution investigation of an NACA 0009 airfoil with an 80-percent-chord plain flap and three tabs

Description: Pressure-distribution tests of an NACA 0009 airfoil with an 80-percent-chord plain flap and three plain tabs, having chord of 10, 20, and 30 percent of the flap chord, were made. Section data suitable for application to the design of horizontal and vertical tail surfaces were obtained. Resultant-pressure diagrams for the airfoil with the flap and the 20-percent-chord tab are presented. Plots are also given of increments of normal-force and hinge-moment coefficients for the airfoil, the flap, an… more
Date: May 1940
Creator: Ames, Milton B., Jr. & Sears, Richard I.
Partner: UNT Libraries Government Documents Department
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Pressure-distribution investigation on an NACA 0009 airfoil with a 30-percent-chord plain flap and three tabs

Description: From Summary: "Pressure-distribution tests of an NACA 0009 airfoil with a 30-percent-chord plain flap and three plain tabs, having chords 10, 20, and 30 percent of the flap chord, were made. The purpose of these tests was to continue an investigation to supply structural and aerodynamic section data that may be applied to the design of horizontal and vertical tail surfaces. The results are presented as diagrams of resultant pressures and of resultant-pressure increments for the airfoil with the… more
Date: May 1940
Creator: Ames, Milton B., Jr. & Sears, Richard I.
Partner: UNT Libraries Government Documents Department
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Some Data on the Static Longitudinal Stability and Control of Airplanes: Design of Control Surfaces

Description: In the solution of a number of problems on the stability and controllability of airplanes, there arises the necessity for knowing the characteristics of the tail surfaces of the types in common use today. Of those characteristics, the most important are the effectiveness and hinge moments of the tail surfaces. As has been shown in the present paper, there exists the possibility of determining these characteristics by the formulas obtained with a degree of accuracy sufficient for the purposes of… more
Date: May 1940
Creator: Martinov, A. & Kolosov, E.
Partner: UNT Libraries Government Documents Department
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Wind-tunnel investigation of two airfoils with 25-percent-chord Gwinn and plain flaps

Description: Aerodynamic force tests of an NACA 23018 airfoil with a Gwinn flap having a chord 25 percent of the overall chord and of an NACA 23015 airfoil with a plain flap having a 25-percent chord were conducted to determine the relative merits of the Gwinn and the plain flaps. The tests indicated that, based on speed-range ratios, the plain flap was more effective than the Gwinn flap. At small flap deflections, the plain flap had lower drag coefficients at lift-coefficient values less than 0.70. For lif… more
Date: May 1940
Creator: Ames, Milton B., Jr.
Partner: UNT Libraries Government Documents Department
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Pressure available for cooling with cowling flaps

Description: Report presents the results of a full-scale investigation conducted in the NACA 20-foot tunnel to determine the pressure difference available for cooling with cowling flaps. The flaps were applied to an exit slot of smooth contour at 0 degree flap angle. Flap angles of 0 degree, 15 degrees, and 30 degrees were tested. Two propellers were used; propeller c which has conventional round blade shanks and propeller f which has airfoil sections extending closer to the hub. The pressure available for … more
Date: May 9, 1940
Creator: Stickle, George W.; Naiman, Irven & Crigler, John L.
Partner: UNT Libraries Government Documents Department
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Pressure distribution over NACA 23012 airfoil with a slotted and a split flap

Description: A pressure-distribution investigation has been conducted in the NACA 4 by 6-foot vertical wind tunnel to determine the air loads on an NACA 23012 airfoil in combination with a 25.66-percent-chord slotted flap and a 20-percent-chord split flap. Pressures were measured on both the upper and the lower surfaces of the main airfoil and the flaps for several angles of attack and at several flap settings. The data, presented as pressure diagrams and as graphs of the section coefficients for the flap a… more
Date: May 28, 1940
Creator: Harris, Thomas A. & Lowry, John G.
Partner: UNT Libraries Government Documents Department
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Comparison of Intercooler Characteristics

Description: "A method is presented of comparing the performance, weight, and general dimensional characteristics of inter-coolers. The performance and dimensional characteristics covered in the comparisons are cooling effectiveness, pressure drops and weight flows of the charge and cooling air, power losses, volume, frontal area, and width. A method of presenting intercooler data is described in which two types of charts are plotted; (1) A performance chart setting forth all the important characteristics o… more
Date: May 1941
Creator: Reuter, J. George & Valerino, Michael F.
Partner: UNT Libraries Government Documents Department
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Critical Compressive Stress for Flat Rectangular Plates Supported Along all Edges and Elastically Restrained Against Rotation Along the Unloaded Edges

Description: A chart is presented for the values of the coefficient in the formula for the critical compressive stress at which buckling may be expected to occur in flat rectangular plates supported along all edges and, in addition, elastically restrained against rotation along the unloaded edges. The mathematical derivations of the formulas required in the construction of the chart are given.
Date: May 1941
Creator: Lundquist, Eugene E. & Stowell, Elbridge Z.
Partner: UNT Libraries Government Documents Department
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Cylinder Barrel Cooling With Bonded Preformed Copper Fins

Description: Report presenting testing of preformed copper fins which were furnace-brazed to a steel-cylinder barrel. The barrel was electrically heated and blower-cooled to determine heat overall heat-transfer coefficient. Information regarding potential future adaptations of the fins are provided.
Date: May 1941
Creator: Foster, H. H. & Ellerbrock, H. H., Jr.
Partner: UNT Libraries Government Documents Department
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Dynamic Similitude in Internal-Combustion Engines

Description: In this report it will be seen that the piston speed - as, moreover, any other speed, such as bearing velocity - must be independent of the quantity dimensions and must be a representative quantity similar to the high speed and the specific weight per horsepower.
Date: May 1941
Creator: Lutz, O.
Partner: UNT Libraries Government Documents Department
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Effect of Propeller Operation on the Pitching Moments of Single-Engine Monoplanes

Description: Report presenting an investigation of the effects of propeller operation on pitching moments with particular reference to the effect of propeller forces, the field of flow in the slipstream, and the increments of lift on the wing and the tail. A procedure, directly applicable only to single-engine monoplanes without flaps, has been set up for predicting the effect of propeller operation on pitching moments as well.
Date: May 1941
Creator: Goett, Harry J. & Pass, H. R.
Partner: UNT Libraries Government Documents Department
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A flight investigation of the boundary-layer characteristics and profile drag of the NACA 35-215 laminar-flow airfoil at high Reynolds numbers

Description: Report presenting testing to determine the boundary layer characteristics and profile drag of the NACA 35-215 airfoil section at high Reynolds numbers. The results indicated that a forward movement of the transition point occurred at about 3 percent of the chord due to operation of the engines and propellers.
Date: May 1941
Creator: Platt, Robert C.
Partner: UNT Libraries Government Documents Department
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Heat Transfer in Geometrically Similar Cylinders

Description: The power and heat-stress conditions of geometrically similar engines are discussed. The advantages accruing from smaller cylinder dimensions are higher specific horsepower, lower weight per horsepower, lower piston temperature, and less frontal area, with reduced detonation tendency.
Date: May 1941
Creator: Riekert, P. & Held, A.
Partner: UNT Libraries Government Documents Department
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Performance Characteristics of an Aircraft Engine with Exhaust Turbine Supercharger, Special Report

Description: "The Pratt and Whitney Aircraft company and the Naval Aircraft Factory of the United States Navy cooperated in a laboratory and flight program of tests on an exhaust turbine supercharger. Two series of dynamometer tests of the engine super-charger combination were completed under simulated altitude conditions. One series of hot gas-chamber tests was conducted by the manufacturer of the supercharger" (p. 1).
Date: May 1941
Creator: Lester, E. M. & Paulson, W. A.
Partner: UNT Libraries Government Documents Department
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Restraint Provided a Flat Rectangular Plate by a Sturdy Stiffener Along an Edge of the Plate, Special Report

Description: A sturdy stiffener is defined as a stiffener of such proportions that it does not suffer cross-sectional distortion when moments are applied to some part of the cross section. When such a stiffener is attached to one edge of a plate, it will resist rotation of that edge of the plate by means of its torsional properties. A formula is given for the restraint coefficient provided the plate by such a stiffener. This coefficient is required for the calculation of the critical compressive stress of t… more
Date: May 1941
Creator: Lundquist, Eugene E. & Stowell, Elbridge Z.
Partner: UNT Libraries Government Documents Department
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Spin Tests of a Low-Wing Monoplane to Investigate Scale Effect in the Model Test Range

Description: "Concurrent tests were performed on a 1/16 and a 1/20 scale model (wing spans of 2.64 and 2.11 ft. respectively) of a modern low wing monoplane in the NACA 15 foot free-spinning wind tunnel. Results are presented in the form of charts that afford a direct comparison between the spins of the two models for a number of different conditions. Qualitatively, the same characteristic effects of control disposition, mass distribution, and dimensional modifications were indicated by both models" (p. 1).
Date: May 1941
Creator: Donlan, Charles J.
Partner: UNT Libraries Government Documents Department
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Spin Tests of Two Models of a Low-Wing Monoplane to Investigate Scale Effect in the Model Test Range

Description: Note presenting testing performed on scale models of a modern low-wing monoplane in the 15-foot free-spinning wind tunnel. Results are presented in the form of charts that afford a direct comparison between the spins of the two models for a number of different conditions. The results indicate that, within the range of Reynolds numbers used in the present investigation, such factors as difficulty of ballasting and testing are more important in determining proper model size than the changes in sc… more
Date: May 1941
Creator: Donlan, Charles J.
Partner: UNT Libraries Government Documents Department
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Stresses and Deflections in Thin Shells and Curved Plates Due to Concentrated and Variously Distributed Loading

Description: Note presenting tests made on cylindrical and spherical shells to determine the local stresses and deflections produced by concentrated and variously distributed loading. The results are correlated with those of earlier experiments, and empirical formulas based on the data are proposed. Data are presented on the effect of severe prestressing on stiffness and on the efficiency of welded lugs of various forms in transmitting a load to a thin shell without producing excessive local stresses.
Date: May 1941
Creator: Roark, Raymond J.
Partner: UNT Libraries Government Documents Department
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Wind-tunnel investigation of an NACA 23012 airfoil with several arrangements of slotted flaps with extended lips

Description: "An investigation was made in the NACA 7- by 10-foot wind tunnel to determine the effect of slot-lip location on the aerodynamic section characteristics of an NACA 23012 airfoil with a 30-percent-chord slotted flap. Tests were made with slot lips located at 90 and 100 percent of the airfoil chord and with two different flap shapes. The results are compared with a slotted flap previously developed by the National advisory Committee for Aeronautics with a slot lip located at 83 percent of the air… more
Date: May 1941
Creator: Lowry, John G.
Partner: UNT Libraries Government Documents Department
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