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The effect of cowling on cylinder temperatures and performance of a Wright J-5 engine

Description: This report presents the results of tests conducted to determine the effect of different amounts and kinds of cowling on the performance and cylinder temperatures of a standard Wright J-5 engine. These tests were conducted in conjunction with drag and propeller tests in which the same cowlings were used. Four different cowlings were investigated varying from the one extreme of no cowling on the engine to the other extreme of the engine completely cowled and the cooling air flowing inside the co… more
Date: May 2, 1929
Creator: Schey, Oscar W. & Biermann, Arnold E.
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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Full-scale tests of NACA cowlings

Description: A comprehensive investigation has been carried on with full-scale models in the NACA 20-foot wind tunnel, the general purpose of which is to furnish information in regard to the physical functioning of the composite propeller-nacelle unit under all conditions of take-off, taxiing, and normal flight. This report deals exclusively with the cowling characteristics under condition of normal flight and includes the results of tests of numerous combinations of more than a dozen nose cowlings, about a… more
Date: May 18, 1936
Creator: Theodorsen, Theodore; Brevoort, M. J. & Stickle, George W.
Partner: UNT Libraries Government Documents Department
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Determination of boundary-layer transition on three symmetrical airfoils in the NACA full-scale wind tunnel

Description: For the purpose of studying the transition from laminar to turbulent flow, boundary-layer measurements were made in the NACA full-scale wind tunnel on three symmetrical airfoils of NACA 0009, 0012, and 0018 sections. The effects of variations in lift coefficient, Reynolds number, and airfoil thickness on transition were investigated. Air speed in the boundary layer was measured by total-head tubes and by hot wires; a comparison of transition as indicated by the two techniques was obtained. The … more
Date: May 26, 1938
Creator: Silverstein, Abe & Becker, John V.
Partner: UNT Libraries Government Documents Department
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The Effect of Compressibility on Eight Full-Scale Propellers Operating in the Take-Off and Climbing Range

Description: "Tests were made of eight full-scale propellers of different shape at various tip speeds up to about 1,000 feet per second. The range of blade-angle settings investigated was from 10 degrees to 30 degrees at the 0.75 radius. The results indicate that a loss in propulsive efficiency occurred at tip speeds from 0.5 to 0.7 the velocity of sound for the take-off and climbing conditions" (p. 517).
Date: May 18, 1938
Creator: Biermann, David & Hartman, Edwin P.
Partner: UNT Libraries Government Documents Department
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Propulsion of a flapping and oscillating airfoil

Description: Formulas are given for the propelling or drag force experience in a uniform air stream by an airfoil or an airfoil-aileron combination, oscillating in any of three degrees of freedom; vertical flapping, torsional oscillations about a fixed axis parallel to the span, and angular oscillations of the aileron about a hinge.
Date: May 4, 1936
Creator: Garrick, I. E.
Partner: UNT Libraries Government Documents Department
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Vibration response of airplane structures

Description: This report presents test results of experiments on the vibration-response characteristics of airplane structures on the ground and in flight. It also gives details regarding the construction and operation of vibration instruments developed by the National Advisory Committee for Aeronautics.
Date: May 10, 1934
Creator: Theodorsen, Theodore & Gelalles, A. G.
Partner: UNT Libraries Government Documents Department
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A Flight Investigation of the Lateral Control Characteristics of Short Wide Ailerons and Various Spoilers With Different Amounts of Wing Dihedral

Description: This report presents the results of flight tests made to determine the lateral control characteristics of short wide ailerons and spoilers, as a consequence of the promise shown in wind-tunnel tests by these devices as means of obtaining lateral control, particularly at angles of attack above the stall. Several forms of spoilers, front-hinge, rear-hinge, plain retractable, and saw-tooth retractable were tested alone and in combination with the ailerons. The tests were made with several differen… more
Date: May 19, 1934
Creator: Weick, Fred E.; Soulé, Hartley A. & Gough, Melvin N.
Partner: UNT Libraries Government Documents Department
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A description and test results of a spark-ignition and a compression-ignition 2-stroke-cycle engine

Description: This report presents performance results of air cooled and water-cooled engines. The results obtained were sufficiently promising to warrant further investigation with fuel injection and spark ignition, with the same arrangement of inlet ports and exhaust valves at the bottom of the cylinder and the exhaust gases discharged through two poppet valves in the cylinder head. The displacement of the engine was 118 cubic inches. Optimum performance was obtained with the inlet air directed into the cy… more
Date: May 14, 1934
Creator: Spanogle, J. A. & Whitney, E. G.
Partner: UNT Libraries Government Documents Department
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Computation of the two-dimensional flow in a laminar boundary layer

Description: A comparison is made of the boundary-layer flow computed by the approximate method developed by K. Pohlhausen with the exact solutions which have been published for several special cases. A modification of Pohlhausen's method has been developed which extends the range of application at the expense of some decrease in the accuracy of the approximations.
Date: May 1934
Creator: Dryden, Hugh L.
Partner: UNT Libraries Government Documents Department
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Relative loading on biplane wings of unequal chords

Description: It is shown that the lift distribution for a biplane with unequal chords may be calculated by the method developed in NACA Technical report no. 458 if corrections are made for the inequality in chord lengths. The method is applied to four cases in which the upper chord was greater than the lower and good agreement is obtained between observed and calculated lift coefficients.
Date: May 18, 1934
Creator: Diehl, Walter S.
Partner: UNT Libraries Government Documents Department
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Tests in the variable-density wind tunnel of related airfoils having the maximum camber unusually far forward

Description: A family of related airfoils having the position of maximum camber unusually far forward was investigated in the variable-density tunnel as an extension of the study recently completed of a large number of related airfoils. The new airfoils gave improved characteristics over those previously investigated, especially in regard to the pitching moment. Some of the new sections are markedly superior to well-known and commonly used sections and should replace them in applications requiring a slightl… more
Date: May 7, 1935
Creator: Jacobs, Eastman N. & Pinkerton, Robert M.
Partner: UNT Libraries Government Documents Department
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Investigation of Full-Scale Split Trailing-Edge Wing Flaps With Various Chords and Hinge Locations

Description: This report gives the results of an investigation conducted in the NACA full-scale wind tunnel on a small parasol monoplane equipped with three different split trailing-edge wing flaps. The object of the investigation was to determine and correlate data on the characteristics of the airplane and flaps as affected by variation in flap chord, flap deflection, and flap location along the wing chord. The results give the lift, the drag, and the pitching moment characteristics of the airplane, and t… more
Date: May 10, 1935
Creator: Wallace, Rudolf
Partner: UNT Libraries Government Documents Department
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Characteristics of Clark Y airfoils of small aspect ratios

Description: This report presents the results of a series of wind tunnel tests showing the force, moment, and autorotational characteristics of Clark Y airfoils having aspect ratios varying from 0.5 to 3. An airfoil of rectangular plan form was tested with rectangular tips, flared tips, and semicircular tips. Tests were also made on one airfoil of circular plan form and two airfoils of elliptical plan form. The tests revealed a marked delay of the stall and a decided increase in values of maximum lift coeff… more
Date: May 5, 1932
Creator: Zimmerman, C. H.
Partner: UNT Libraries Government Documents Department
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Force measurements on a 1/40-scale model of the U. S. Airship "Akron"

Description: This report describes a series of tests made on a 1/40-scale model of the U. S. Airship "Akron" (ZRS-4) for the purpose of determining the drag, lift, and pitching moments of the bare hull and of the hull equipped with two different sets of fins. Measurements were also made of the elevator forces and hinge moments.
Date: May 6, 1932
Creator: Freeman, Hugh B.
Partner: UNT Libraries Government Documents Department
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Rates of fuel discharge as affected by the design of fuel-injection systems for internal-combustion engines

Description: Using the method of weighing fuel collected in a receiver during a definite interval of the injection period, rates of discharge were determined, and the effects noted, when various changes were made in a fuel-injection system. The injection system consisted primarily of a by-pass controlled fuel pump and an automatic injection valve. The variables of the system studied were the pump speed, pump-throttle setting, discharge-orifice diameter, injection-valve opening and closing pressures, and inj… more
Date: May 15, 1932
Creator: Gelalles, A. G. & Marsh, E. T.
Partner: UNT Libraries Government Documents Department
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Lift and drag characteristics and gliding performance of an autogiro as determined in flight

Description: From Summary: "This report presents the results of flight test of the Pitcairn "PCA-2" autogiro. Lift and drag coefficients with the propeller stopped have been determined over approximately a 90 degree range of angles of attack. Based on the sum of fixed-wing and swept-disk areas, the maximum lift coefficient is 0.895, the minimum drag coefficient with propeller stopped is 0.015, and the maximum l/d with propeller stopped is 4.8. Lift coefficients were found also with the propeller delivering … more
Date: May 2, 1932
Creator: Wheatley, John B.
Partner: UNT Libraries Government Documents Department
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Fuel vaporization and its effect on combustion in a high-speed compression-ignition engine

Description: "The tests discussed in this report were conducted to determine whether or not there is appreciable vaporization of the fuel injected into a high-speed compression-ignition engine during the time available for injection and combustion. The effects of injection advance angle and fuel boiling temperature were investigated. The results show that an appreciable amount of the fuel is vaporized during injection even though the temperature and pressure conditions in the engine are not sufficient to ca… more
Date: May 4, 1932
Creator: Rothrock, A. M. & Waldron, C. D.
Partner: UNT Libraries Government Documents Department
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The effect of area aspect ratio on the yawing moments of rudders at large angles of pitch on three fuselages

Description: This reports presents the results of measurements made of yawing moments produced by rudder displacement for seven rudders mounted on each of three fuselages at angles of pitch of 0 degree, 8 degrees, 12 degrees, 20 degrees, 30 degrees and 40 degrees. The dimensions of the rudders were selected to cover the range of areas and aspect ratios commonly used, while the ratios of rudder area to fin area and of rudder chord to fin chord were kept approximately constant. An important result of the meas… more
Date: May 16, 1932
Creator: Dryden, Hugh L. & Monish, B. H.
Partner: UNT Libraries Government Documents Department
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Negative Thrust and Torque Characteristics of an Adjustable-Pitch Metal Propeller

Description: This report presents the results of a series of negative thrust and torque measurements made with a 4 foot diameter model of a conventional aluminum-alloy propeller. The tests were made in the 20-foot propeller-research tunnel of the National Advisory Committee for Aeronautics. The results show that the negative thrust is considerably affected by the shape and size of the body behind the propeller, that the maximum negative thrust increases with decrease in blade-angle setting, and that the dra… more
Date: May 23, 1933
Creator: Hartman, Edwin P.
Partner: UNT Libraries Government Documents Department
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Experimental Verification of the Theory of Wind-Tunnel Boundary Interference

Description: "The results of an experimental investigation on the boundary-correction factor are presented in this report. The values of the boundary-correction factor from the theory, which at the present time is virtually completed, are given in the report for all conventional types of tunnels. With the isolation of certain disturbing effects, the experimental boundary-correction factor was found to be in satisfactory agreement with the theoretically predicted values, thus verifying the soundness and suff… more
Date: May 18, 1933
Creator: Theodorsen, Theodore & Silverstein, Abe
Partner: UNT Libraries Government Documents Department
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Stability of Thin-Walled Tubes Under Torsion

Description: "In this report a theoretical solution is developed for the torsion on a round thin-walled tube for which the walls become unstable. The results of this theory are given by a few simple formulas and curves which cover all cases. The differential equations of equilibrium are derived in a simpler form than previously found, it being shown that many items can be neglected" (p. 3).
Date: May 5, 1933
Creator: Donnell, L. H.
Partner: UNT Libraries Government Documents Department
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