National Advisory Committee for Aeronautics (NACA) - 30 Matching Results
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- Adaptor for Measuring Principal Strains With Tuckerman Strain Gage
- Report discussing an adapter which uses three Tuckerman optical strain gages to measure the displacement of the three vortices of an equilateral triangle along lines 120 degrees apart. These displacements are substituted in well-known equations in order to compute the magnitude and direction of the principal strains. Tests of the adaptor indicate that principal strains over a gage length of 1.42 inch may be measured with a systematic error not exceeding 4 percent and a mean observational error of the order of + or minus 0.000006. The maximum observed error in strain was of the order of 0.00006. The directions of principal strains for unidirectional stress were measured with the adaptor with an average error of the order of 1 degree.
- Bearing tests of magnesium-alloy sheet
- From Summary: "Bearing tests of AM-3S, AM-52S, and AM-C57S magnesium-alloy sheet in various thicknesses and tempers were made. Bearing yield and ultimate strengths were determined and compared for various edge distances and for various ratios of loading-pin diameter to sheet thickness. Tensile strengths were determined and ratios of average bearing yield and ultimate strength to tensile strength are given."
- The effect of dead rise upon the high-angle porpoising characteristics of two planing surfaces in tandem
- Report presenting porpoising tests of three rudimentary models composed of two V-bottom planing surfaces in tandem and fitted with a tail plane. The upper and lower branches of the upper trim limit of stability were determined for three angles of dead rise and two depths of step.
- Effect of Exhaust Back Pressure on Engine Power
- Report presenting data on the effect of exhaust back pressure on engine power for 14 aircraft engines. The data showed that the effect of exhaust back pressure on engine power varies with engine speed, range of back pressure and manifold pressure involved, and engine type. The only method of accurately determining the effect of back pressure on engine power than can currently be recommended is to test the specific engine type at the engine speed for which data are desired.
- Effect of wing loading and altitude on lateral stability and control characteristics of an airplane as determined by tests of a model in the free-flight tunnel
- Report presenting an investigation to determine the effects of wing loading and altitude on lateral stability and control in the free-flight tunnel. The results of flight tests of the model were correlated with calculated stability boundaries, and an effort was made to determine for each loading condition the airplane configuration that gave the best flight characteristics. Results regarding the lateral stability, lateral control, and general flight behavior are provided.
- The Exact Solution of Shear-Lag Problems in Flat Panels and Box Beams Assumed Rigid in the Transverse Direction
- "A mathematical procedure is herein developed for obtaining exact solutions of shear-lag problems in flat panels and box beams: the method is based on the assumption that the amount of stretching of the sheets in the direction perpendicular to the direction of essential normal stresses is negligible. Explicit solutions, including the treatment of cut-outs, are given for several cases and numerical results are presented in graphic and tabular form. The general theory is presented in a from which further solutions can be readily obtained" (p. 1).
- Experimental Determination of the Yawing Moment Due to Yawing Contributed by the Wing, Fuselage, and Vertical Tail of a Midwing Airplane Model
- Report presenting values of the lateral-stability derivative, the rate of change of yawing-moment coefficient with yawing angular velocity, contributed by the wing, the fuselage, and the vertical tail, which have been determined for a midwing airplane model by the free-oscillation method.
- Fatigue Characteristics of Spot-Welded 24S-T Aluminum Alloy
- Report presenting the results of an investigation of the fatigue characteristics of spot-welded 24S-T aluminum alloy. The static shear strength of spot welds in lap joints of 24S-T alclad increases with increasing sheet thickness for thicknesses in the range of 0.025 inch to 0.032 inch.
- Flight tests of an all-movable vertical tail on the Fairchild XR2K-1 airplane
- Report presenting flight tests of an all-movable vertical tail of reduced area of the Fairchild XR2K-1 airplane. Results are in agreement with previously obtained data on a larger all-movable tail. Results regarding rudder effectiveness, directional stability, rudder-free lateral motion, rudder hinge moments, and areas of future research are provided.
- Flight Tests of Various Tail Modifications on the Brewster XSBA-1 Airplane 1: Measurements of Flying Qualities With Original Tail Surfaces
- Report presenting a series of tests of the Brewster XSBA-1 airplane conducted to determine the effect of various tail modifications. The current report describes an investigation of flying qualities of the airplanes with its original tail surfaces. Testing regarding longitudinal stability and control and stalling characteristics are provided.
- Full-scale tunnel measurements of the pressures on the elevator and fuselage of the Curtiss XP-55 airplane
- Report presenting force tests and measurements of the pressure distribution over the elevator and forward part of the fuselage on a flying model of the Curtiss XP-55 airplane in the full-scale tunnel. The results of the elevator pressure measurements are given in this paper. Results regarding chordwise pressure distributions, span-load distribution, and normal-force coefficients are provided.
- Gasoline-water distribution coefficients of xylidines
- Report presenting experimental data on the distribution coefficients of technical xylidines for the system gasoline-water. The distribution coefficient is defined as the ratio of the concentration of xylidines in the gasoline layer to that in the water layer. Results regarding the effect of concentration of xylidines, effect of aromatic content of fuel, effect of sea water, and effect of temperature are provided.
- The Locus of Possible Positions of a Heavy Bomber in Space After a 12-Second Time Interval
- Report presenting an investigation to determine the loci of possible positions of a heavy bomber in space following a 12-second interval.
- The low-temperature solubility of technical xylidine in aviation gasoline
- Report presenting testing to determine the low-temperature solubility of technical xylidines in aviation gasoline. Testing included measuring the cloud point, or incipient separation temperature, at several concentrations of technical xylidines in a 65-octane-number clear gasoline without aromatics and with aromatics added in various percentages up to 15 percent by volume and a grade 130, specification AN-F-28, amendment 2, gasoline.
- Mechanical Tests of Macerated Phenolic Molding Material
- Report presenting results of mechanical tests of macerated phenolic molding material. The following tests were performed: static tension, compression, torsion, and flexure tests; long-time creep tests at different stresses, tests for time to fracture under long-continued constant load; Izod and Charpy impact tests; bending fatigue tests at different ranges of stress; rotating-beam fatigue tests at different speeds of testing; rotating beam fatigue tests of notched specimens; and torsion fatigue tests.
- Preliminary Tank Tests With Planing-Tail Seaplane Hulls
- Report presenting testing made with simplified models of two types of hulls that differ considerably from conventional types. Both have a single main planing surface that is combined with after-planing surfaces placed directly below the aerodynamic tail surfaces. Results regarding an investigation of twin planing tails, a single-planing tail, and potentialities indicated by tests are provided.
- Recommended Test Procedure for Aircraft Engine Turbosupercharger Power Plants
- Report describes a procedure for instrumenting, testing, and presenting the overall characteristics of any engine turbosupercharger installation. The preflight analysis of the system, required testing, importance of accurate data recording, measurements to record, methods of measuring, and presentation of results are also included.
- Researches on Preliminary Chemical Reactions in Spark-Ignition Engines
- "Chemical reactions can demonstrably occur in a fuel-air mixture compressed in the working cylinder of an Otto-cycle (spark ignition) internal-combustion engine even before the charge is ignited by the flame proceeding from the sparking plug. These are the so-called "prelinminary reactions" ("pre-flame" combustion or oxidation), and an exact knowledge of their characteristic development is of great importance for a correct appreciation of the phenomena of engine-knock (detonation), and consequently for its avoidance. Such reactions can be studied either in a working engine cylinder or in a combustion bomb" (p. 1).
- Resume of Hinge-Moment Data for Unshielded Horn- Balanced Control Surfaces
- Report summarizes the available hinge-moment data for unshielded horn-balanced control surfaces. The purpose is to correlate the available data to assist with estimating the balance characteristics for use in the design and alteration of control surfaces with horn balances. Plan forms and variation of incremental hinge-moment-coefficient slopes with balance coefficients are presented.
- Some Systematic Model Experiments on the Porpoising Characteristics of Flying-Boat Hulls
- "This report presents the results of systematic model experiments on the hydrodynamic characteristics of flying boats, aimed primarily at developing a comprehensive view of the factors influencing porpoising and of their relative importance. The experiments 'radiated' from a given reference ship; they embrace changes, over reasonably wide ranges, in the value of each of a number of variables, treated independently. The experimental results are summarized in a series of 25 figures, each of which gives the complete data for all the modifications of one variable" (p. 1).
- Tank tests of a 1/8-size dynamic model of the PB2Y-3 airplane with increased power: NACA model 131
- Report presenting a study of the installation of 1800-horsepower engines in the PB2Y-3 airplane in place of the current 1200-horsepower engines. Stability and spray tests were made to determine the performance of the model on the water when tested at both the present and projected conditions of gross load and engine power. Results regarding aerodynamic tests and hydrodynamic tests are provided.
- Tank Tests of a 1/8-Size Dynamic Model of the PB2Y-3 Airplane with Simulated Jet Motors: NACA Models 131J, 131J-1 and 131J-2
- Report presenting an investigation to determine the effect of jet motors on the stability of the PB2Y-3 airplane at a gross load of 76,000 pounds. Results regarding Model 131J, Model 131J-1, and Model 131J-2 are provided.
- Test Data on the Shear Strength of Joints Assembled With Round-Head and Brazier-Head Rivets
- Report discusses data obtained from testing shear of joints riveted with round-head and brazier-head rivets. The tightness of the rivets is also compared for one value of rivet diameter. The load-displacement curves and comparison of load at various values of permanent displacement are presented for both types of rivets.
- Tests of 10-Inch 24S-T Aluminum-Alloy Shear Panels With 1-1/2-Inch Holes
- Report discusses the results of testing on "10-inch shear panels of 24S-T aluminum alloy with 1.5 inch holes to determine the stress concentration at static rupture and the deformation characteristics" (from Summary). The strength of the perforated specimens is compared to the solid specimens and the critical stresses are computed. The stress at which permanent set occurs was also measured.
- Thermodynamic Design of Double-Panel, Air-Heated Windshields for Ice Prevention
- Report details the development of design equations for double-panel, air-heated windshields with ice prevention properties. The application of the equations and suggestions for experimental flight testing are described.
- Wind-Tunnel Investigation of Control-Surface Characteristics 14: NACA 0009 Airfoil With a 20-Percent-Chord Double Plain Flap
- Report discusses the results of force testing of the aerodynamic characteristics of an NACA 0009 airfoil with a double plain flap; it consisted of a plain forward flap with a chord 20 percent of the airfoil chord and a plan rearward flap with a chord 15 percent of the airfoil chord. Comparisons were made to the characteristics of a 0.50c single plain flap. The lift, hinge moments, drag, and pitching moments are described.
- Wind-Tunnel Investigation of Effect of Yaw on Lateral-Stability Characteristics 5: Symmetrically Tapered Wing With a Circular Fuselage Having a Horizontal and a Vertical Tail
- Report discussing testing to determine the effect of a horizontal tail on the lateral-stability characteristics of a high-wing, a midwing, and a low-wing monoplane. The model was created from a circular fuselage, an NACA 23012 tapered wing, and an NACA 0009 horizontal tail surface. Information about the effective aspect ratio of the tail, restoring moment of yaw, and vertical-tail effectiveness as compared to the wing position is provided.
- Wind Tunnel Tests of Ailerons at Various Speeds 1: Ailerons of 0.20 Airfoil Chord and True Contour With 0.35 Aileron-Chord Extreme Blunt Nose Balance on the NACA 66,2-216 Airfoil
- "Hinge-moment, lift, and pressure-distribution measurements were made in the two-dimensional test section of the NACA stability tunnel on a blunt-nose balance-type aileron on an NACA 66,2-216 airfoil at speeds up to 360 miles per hour corresponding to a Mach number of 0.475. The tests were made primarily to determine the effect of speed on the action of this type of aileron. The balance-nose radii of the aileron were varied from 0 to 0.02 of the airfoil chord and the gap width was varied from 0.0005 to 0.0107 of the airfoil chord. Tests were also made with the gap sealed" (p. 1).
- Wind-tunnel tests of ailerons at various speeds 2: ailerons of 0.20 airfoil chord and true contour with 0.60 aileron-chord sealed internal balance on the NACA 66,2-216 airfoil
- Report presenting hinge-moment, lift, pressure difference across the balance, and pressure-distribution measurements in the two-dimensional test section of the stability tunnel on a 0.60 aileron-chord sealed internal-balance aileron on a specified NACA airfoil. The primary test objective was to determine the effect of speed on the action of the aileron.
- Wind-tunnel vibration tests of a four-blade single rotating pusher propeller
- Report presenting vibration tests of a four-blade single-rotating propeller operating in a simulated pusher condition performed because the combination of wake and downwash behind a wing might provide serious excitation for reactionless vibrations of propellers with four or more blades. Measurements of propeller vibratory stress were made for various airspeeds, engine speeds, and engine powers.