National Advisory Committee for Aeronautics (NACA) - 1,263 Matching Results
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- Lift and drag data for 30 pusher-propeller shaft housings on an NACA 65,3-018 airfoil section
- Report presenting tests in the two-dimensional low-turbulence pressure tunnel to study the interference effects of various pusher-propeller shaft-housing combinations on a low-drag airfoil. Thirty different combinations were tested, variations being made in shaft size, shape, angle, and fillet.
- The Effects of Roughness at High Reynolds Numbers on the Lift and Drag Characteristics of Three Thick Airfoils
- "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).
- 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
- 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.
- Interference effects of longitudinal flat plates on low-drag airfoils
- 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.
- Lift and Drag Characteristics of a Low-Drag Airfoil With Slotted Flap Submitted by Curtiss-Wright Corporation
- Report presenting a wooden model equipped with a slotted flap that was tested in the two-dimensional tunnel. It represented a wing section of the Curtiss-Wright P-60A airplane and the NACA 66,2-118 section. Results regarding lift characteristics, drag coefficients, and flap deflection characteristics are provided.
- Pressure-Distribution Measurements of a Low-Drag Airfoil With Slotted Flap Submitted by Curtiss-Wright Corporation
- "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).
- Pressure-Distribution Measurements of a Model of a Davis Wing Section with Fowler Flap Submitted by Consolidated Aircraft Corporation
- 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.
- Pressure-distribution measurements of two airfoil models with Fowler flaps submitted by Consolidated Aircraft Corporation as alternative wing sections of the XB-32 airplane
- 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.
- Tests of four models representing intermediate sections of the XB-33 airplane including sections with slotted flap and ailerons
- 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.
- Lift and Drag Tests of Three Airfoil Models With Fowler Flaps Submitted by Consolidated Aircraft Corporation
- 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.
- Variation with Mach Number of Static and Total Pressures Through Various Screens
- "Tests were conducted in the Langley 24-inch highspeed tunnel to ascertain the static-pressure and total-pressure losses through screens ranging in mesh from 3 to 12 wires per inch and in wire diameter from 0.023 to 0.041 inch. Data were obtained from a Mach number of approximately 0.20 up to the maximum (choking) Mach number obtainable for each screen. The results of this investigation indicate that the pressure losses increase with increasing Mach number until the choking Mach number, which can be computed, is reached" (p. 1).
- Tests of a 1/14-Scale Powered Model of the XB-36 Airplane in the Langley 19-Foot Pressure Tunnel 1: Stalling Characteristics and Aileron Effectiveness of Several Wing and Flap Arrangements
- Report discussing an investigation into the stalling characteristics, aileron effectiveness, and longitudinal stability of a scale model of the XB-36 airplane. The model was tested with the original configuration as well as with several modifications to the outboard panels and flap arrangement.
- A method for calculating heat transfer in the laminar flow region of bodies
- Report presenting a practical method for determining the chordwise distribution of the rate of heat transfer from the surface of a wing or body of revolution to air. The method is limited to use to the determination of heat transfer fro the forward section of such bodies when the flow is laminar.
- Wall interference in a two-dimensional-flow wind tunnel with consideration of the effect of compressibility
- Report presenting tunnel-wall corrections for an airfoil of finite thickness and camber in a two-dimensional-flow wind tunnel. The theory takes account of the effects of the wake of the airfoil and of the compressibility of the fluid and is based on the assumption that the chord of the airfoil is small in comparison with the height of the tunnel. The theoretical results are compared with the small amount of low-speed experimental data available and agreement is seen to be satisfactory, even for relatively large values of the chord-height ratio.
- Knock-Limited Performance of Blends of AN-F-28 Fuel Containing 2 Percent Aromatic Amines 5
- Report discussing testing of 2-percent additions of seven aromatic amines on the knock-limited performance of 28-R fuel in a CFR engine. The most effective antiknock additives are described.
- The Knock-Limited Performance of Several Fuels Blended With S-2 Reference Fuel
- Report discussing the results of testing conducted to determine the knock-limited performance of fuel blends containing 80 percent of S-2 reference fuel and 20 percent of several exploratory fuels. Butyl acetate, sec-butyl acetate, isopropyl acetate, sec-butyl alcohol, tert-butyl alcohol, isopropyl alcohol, cyclohexanol, methylcyclohexanol, isobutylcarbinol, sec-butylcarbinol, triethyl borate, and dimethylfuran were examined.
- Trends in Surface-Ignition Temperatures
- Report discusses the variation of surface-ignition temperature with charge density, fuel-air ratio, and surface-ignition advance. Tests on several fuels were conducted on a supercharged CFR engine to determine surface-ignition temperature as a function of the three variables. It was concluded that surface-ignition temperature is not a satisfactory criterion for differentiating between preignition characteristics of different fuels.
- The Effect of Compression Ratio on Knock Limits of High-Performance Fuels in a CFR Engine 1: Blends of Triptane and 28-R Fuel
- Report discussing the knock-limited performance of blends of triptane and 28-R fuel in an F-4 engine at three sets of conditions and three compression ratios. The knock limits of the triptane blends were more sensitive to compression ratio than the 28-R fuel, and the sensitivities of the blends increased as the severity of other engine conditions increased.
- The Effect of Compression Ratio on Knock Limits of High-Performance Fuels in a CFR Engine 2: Blends of 2,2,3-Trimethylpentane with 28-R
- "The knock-limited performance of blends of 0,50; and 100 percent by volume of 2,2,3-trimethylpentane in 28-R fuel determined with a modified F-4 engine at three sets of conditions varying from severe to mild at each of three compression ratios (6.0, 8.0, and 10.0). A comparison of the knock-limited performance of 2,2,3-trimethylpentane with that of triptane (2,2,3-trimethylbutane) is included. The knock-Limited performance of 2,2,3-trimethylpontane was usually more sensitive to either compression ratio or inlet-air temperature than 28-R fuel, but the ratio of the knock-limited indicated mean effective pressure of a given blend containing 2,2,3-trimethypentane and 28-R to the indicated mean effective pressure of 28-R alone was not greatly affected by compression ratio if the engine operating conditions were mild" (p. 1).
- The Effect of Compression Ratio on Knock Limits of High-Performance Fuels in a CFR Engine 3: Blends of 2,3-Dimethylpentane With 28-R
- Report discussing the knock-limited performance of blends of 2,3-dimethylpentane and 23-R fuel in an F-4 engine at three sets of conditions and three compression ratios. The knock-limited performance of 2,3-dimethylpentane has about the same sensitivity to compression ratio and inlet-air temperature as 28-R fuel.
- Knock-limited performance of blends of AN-F-28 fuel containing 2 percent aromatic amines 3
- Report presenting tests to investigate the effect of 2-percent additions of nine aromatic amines on the knock-limited performance of AN-N-28 (28-R) fuel. The results of the testing of antiknock effectivneess of the 27 aromatic amines obtained to date in the program are also summarized.
- Knock-Limited Performance of Blends of AN-F-28 Fuel Containing 2 Percent Aromatic Amines 4
- Report discussing tests on the effect of 2-percent additions of 13 aromatic amines on the knock-limited performance of 28-R fuel in a CFR engine. The amines tested gave good rich mixture response at standard F-4 operating conditions, but were sensitive to engine severity at lean fuel-air ratios.
- Suitability of ethers as aviation fuel components the knock-limited performance of several ethers blended with AN-F-28 fuel
- Report presenting a investigation covering the physical and chemical properties of various ethers as components of aviation fuels. Their antiknock effectiveness and methods of preparation and purification are included. Methyl tert-butyl ether gave the best knock-limited rich mixture response, but isopropyl tert-butyl ether and di-tert-butyl ether gave better results at lean mixtures.
- A Correlation of the Effects of Compression Ratio and Inlet-Air Temperature on the Knock Limits of Aviation Fuels in a CFR Engine 2
- Report presenting the knock-limited performance of nine fuels comprising isolated members of four classes of hydrocarbons in the form of three-dimensional plots of fuel-air ratio, compression temperature, and compression-air density.
- Wind-Tunnel Investigation of Control-Surface Characteristics 3: A Small Aerodynamic Balance of Various Nose Shapes Used With a 30-Percent-Chord Flap on an NACA 0009 Airfoil
- Report presenting tests in the 4- by 6-foot vertical wind tunnel of an NACA 0009 airfoil with a 30-percent-chord flap with a small amount of aerodynamic balance. In the investigation, the effect of balance nose shape and gap at the nose of the flap has been determined. The results indicate that, in general, the lift effectiveness of the flap was unaffected by the addition of a small amount of aerodynamic overhang, and the balance effectiveness of the flap was increased.
- Wind-Tunnel Investigation of Control-Surface Characteristics 4: A Medium Aerodynamic Balance of Various Nose Shapes Used With a 30-Percent-Chord Flap on an NACA 0009 Airfoil
- Report presenting tests made in the 4- by 6-foot vertical wind tunnel of an NACA 0009 airfoil with a 30-percent-chord flap with a medium amount of aerodynamic overhanging balance. In this investigation, the effects of the shape of the flap-nose overhang and the gap at the nose of the flap have been determined. The results indicate that, generally, the lift effectiveness of the aerodynamically balanced flap was increased slightly over that of a plain flap when a blunt or medium flap nose was used on the balanced flap.
- Wind-tunnel investigation of a section of the horizontal tail surface for the Bell XP-63 airplane
- Report presenting force tests conducted on a model of a section of the XP-63 horizontal tail surface in the 4- by 6-foot closed-throat vertical wing tunnel. The angle-of-attack range was from the negative to the positive stall for all flap deflections.
- Tests of NACA 65(216)-420 and 66(218)-420 Airfoils at High Speeds
- Report presenting wind tunnel tests of NACA 65(216)-420 and 66(218)-420 airfoils at speeds up to and slightly above the critical. Section coefficients of lift, drag, and pitching-moment and extensive pressure-distribution data are presented. The critical speed for these airfoils at their design life coefficient of 0.4 is shown to be about 460 miles per hour at seal level and about 415 miles per hour at 25,000 feet altitude.
- High-Speed Wind-Tunnel Tests of a Twin-Fuselage Pursuit Airplane
- Report discussing the aerodynamic characteristics of a twin-fuselage pursuit airplane model, especially at high speeds. Information about the force data and critical Mach numbers for parts of the model is provided. Suggestions for increasing the Mach number of divergence by making modifications to the wing-fuselage fillets and external shape of the radiator are also included.
- Wind Tunnel Tests of Ailerons at Various Speeds 4: Ailerons of 0.20 Airfoil Chord and True Contour With 0.35 Aileron-Chord Extreme Blunt-Nose Balance on the NACA 23012 Airfoil
- Report presenting tests made on an NACA 23012 airfoil fitted with a 20-percent-chord, true-contour aileron with 35-percent-chord, extreme blunt-nose balance. The primary purpose of the investigation was to determine the variation of the aerodynamic characteristics of this type of aileron with airspeed; the effect of variations of gap width and balance-nose radii was also investigated. Results regarding hinge moments, lift, and pitching-moment coefficients are provided.
- Maximum Lift Coefficients of Airplanes Based on Sum of Wing and Tail Areas
- Report discusses the maximum lift coefficients for conventional and tailless airplanes in the gliding and landing conditions. Three areas are used to calculate the coefficients: wing area alone, wing area plus horizontal-tail area, and wing area plus horizontal- and vertical-tail areas.
- Pressure distribution measurements on various surfaces of a 0.2375-scale model of the Douglas XA-26 airplane in the 19-foot pressure tunnel
- Report presenting pressure-distribution measurements on a scale model of the Douglas XA-26 airplane as obtained in the 19-foot pressure tunnel. The measurements were made on the spinner-cowl-nacelle assembly and the fuselage for a range of angles of yaw and angles of attack.
- Tests of a 0.30 scale semispan model of the Douglas XTB2D-1 airplane wing and fuselage combination in the NACA 19-foot pressure tunnel 1: full-span flap and air-brake investigation
- Report presenting testing in the 19-foot pressure tunnel of a scale semispan model of the XTB2D-1 airplane wing and fuselage combination. The purpose of the investigation was to determine the optimum position of the double-slotted flap, the characteristics of the full-span flaps at various deflections in their fully extended position, the effectiveness of deflecting the full-span flaps to small positive angles as a camber changing feature, the stalling characteristics of the wing, and the effectiveness of the flap as a brake when deflected to negative angles.
- Aerodynamic Tests of an M-31 Bomb in the 8-Foot High-Speed Tunnel
- Report presenting aerodynamic tests of a 300-pound M-31 demolition bomb. Force tests at a range of angles of attack were made at Mach number 0.725, which corresponds to a speed of 810 feet per second at sea level. Results regard the drag, lift, and pitching moment are provided.
- Numerical Evaluation of the Wake-Survey Equations for Subsonic Flow Including the Effect of Energy Addition
- Report presenting direct-reading tables and charts for determining the drag or thrust coefficients from wake-survey measurements in the subsonic speed range. Additionally, numerical examples are provided using information from the tables.
- A simplified chart for determining Mach number and true airspeed from airspeed-indicator readings
- "The determination of flight Mach number from measurements of indicated airspeed and pressure altitude is shown to be relatively simple and leads to direct and accurate computation of true airspeed. A simplified chart is presented for determining flight Mach number and true airspeed for a range of values of indicated airspeed, pressure altitude, and air temperature. A table of standard atmospheric values is included" (p. 1).
- The development and application of high-critical-speed nose inlets
- From Summary: "An analysis of the nose-inlet shapes developed in previous investigations to represent the optimum from the standpoint of critical speed has shown that marked similarity exists between the nondimensional profiles of inlets which have widely different proportions and critical speeds. With the nondimensional similarity of such profiles established, the large differences in the critical speeds of these nose inlets must be a function of their proportions. An investigation was undertaken in the Langley 8-foot high-speed tunnel to establish the effects of nose-inlet proportions on critical Mach number and to develop a rational method for the design of high-critical-speed nose inlets to meet desired requirements."
- Air-Flow and Performance Characteristics of Engine-Stage Supercharger of a Double-Row Radial Aircraft Engine 2: Effect of Design Variables
- Report presenting an investigation to determine the effect of the location of the diffuser vanes with respect to the supercharger outlets and the effect of flow conditions at the impeller inlet on the air-flow distribution in the outlets of the engine-stage supercharger of an 18-cylinder double-row radial aircraft engine. The effect of flow conditions at the impeller inlet was investigated by distorting the flow at the inlet and noting the effect in the supercharger outlets. Results regarding the diffuser effect and inlet effect are provided.
- Charts for estimation of the characteristics of a helicopter rotor in forward flight I: profile drag-lift ratio for untwisted rectangular blades
- Report presenting charts showing the rotor profile drag-lift ratio for a helicopter rotor operating in forward flight and having hinged rectangular untwisted blades. The charts are given for a range of power input covering glides, level flight, and moderate rates of climb. A drag curve was used for preparing the charts, and the curve is compared with experimental curves for typical airfoils.
- Flight Investigation of NACA D(Sub S) Cowlings on the XP-42 Airplane 1: High-Inlet-Velocity Cowling with Propeller Cuffs Tested in High-Speed Level Flight
- Report presenting results from a series of flight tests of the maximum speed and cooling characteristics in full-throttle level flight of the XP-42 airplane equipped with a short-nose high-inlet velocity cowling. The results of the tests indicated a maximum speed of 336 miles per hour at 960 horsepower at 25,000 feet. Results regarding maximum speed and pressure and temperatures are provided.
- A theoretical analysis of the effect of aileron inertia and hinge moment on the maximum rolling acceleration of airplanes in abrupt aileron rolls
- Report presenting data on the rolling accelerations of airplanes of different types and sizes in abrupt aileron rolls in connection with a number of maneuverability and flying qualities investigations. An analysis was made to determine the relation between the torque applied to the aileron system by the pilot, the motion of the system, and the subsequent rolling motion of the airplane in abrupt aileron roll.
- An Estimate of the Effect of Engine Supercharging on the Take-Off Thrust of a Typical Helicopter at Different Altitudes and Temperatures
- Report discussing the effects of supercharging on the take-off thrust and useful load for a typical helicopter. Performance of the engine with the supercharger and on the rotor thrust is detailed.
- Flight investigation of the performance and cooling characteristics of a long-nose high-inlet-velocity cowling on the XP-42 airplane
- Report presenting the results of a series of flight tests of the maximum speed and cooling characteristics in high-speed level flight and in climb of the XP-42 airplane equipped with a long-nose high-inlet-velocity cowling. The results indicated that a maximum speed of 338 miles per hour at 870 horsepower at 17,000 feet was achievable, which is above the engine critical altitude. Pressure measurements in the entrances in the cylinder baffles showed a uniform distribution of pressure on the front of the engine in high-speed level flight and a fairly uniform distribution in full-power climb.
- Effect of Changes in Aspect Ratio, Side Area, Flight-Path Angle, and Normal Acceleration on Lateral Stability
- Report presenting computations made to determine the effect of changes in wing aspect ratio, additional side area, flight-path angle, and normal acceleration on the relation between the fin area and the dihedral angle required for spiral and for oscillatory lateral stability for a hypothetical airplane of the pursuit or fighter categories. The diagrams indicate that the effect of wing aspect ratio on lateral stability is small.
- High-Speed Aerodynamic Characteristics of a Four-Engine Bomber Airplane as Determined From Tests of a 0.075-Scale Model
- Report presenting tests of airplane models that included investigations to determine the longitudinal stability and control, effects of various constituent parts or their modification on longitudinal stability and control, critical speed, and distribution of wing load. Some of the changes made in attempts to improve longitudinal control and to increase critical speed included auxiliary control flaps on the lower surface of the wing, revision of the windshield, increase in dimensions of outboard nacelles, and alteration in profile of wing leading edge.
- High-Speed Aerodynamic Characteristics of a Four-Engine Transport Airplane as Determined From Tests of a 0.075-Scale Model
- Report presenting tests made in order to determine the differences in high-speed aerodynamic characteristics between models of a four-engine transport airplane and a similar bomber airplane. The main conclusion found is that the critical Mach number of the transport model is about 0.05 less than that of the bomber model.
- Estimation of F-3 and F-4 Knock-Limited Performance Ratings for Ternary and Quaternary Blends Containing Triptane or Other High-Antiknock Aviation-Fuel Blending Agents
- Report providing charts to assist with estimating F-3 and F-4 knock-limited performance ratings for several ternary and quaternary fuel blends. Several unusual behaviors were noted in the F-3 engines using the aromatic-paraffinic blends, so the charts for them may not be as accurate. General trends observed in different types of fuel are also described.
- An Evaluation of the Knock-Limited Performance of Triptane
- Report discussing an investigation of the knock-limited performance of triptane in F-3 and F-4 rating engines, two full-scale air-cooled aircraft cylinders, and flight tests on a full-scale multicylinder engine. Information about the lead susceptibility and effect of engine operating conditions is also provided.
- Lead susceptibility of paraffins, cycloparaffins, and olefins
- "General relationships for the lead susceptibilities of paraffins, cycloparaffins, and olefins are presented. Methods are described by which the lead response may be estimated for these hydrocarbon classes, whether the lead response is indicated by octane number, critical compression ratio, or indicated mean effective pressure as limited by knock" (p. 1).
- The Effect of Engine Conditions on the Lead Susceptibility of Paraffinic Fuels
- Report presenting an investigation made on a supercharged CFR engine to determine a method for estimating lead susceptibilities of pure or blended paraffinic fuels. As a result of these studies, a chart consisting of a series of straight lines passing through the origin was developed to represent the lead susceptibilities of pure and blended paraffinic fuels in terms of knock-limited indicated mean effective pressures and octane numbers.