National Advisory Committee for Aeronautics (NACA) - 366 Matching Results

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Abstracts Pertaining to Seaplanes
Report discussing about 400 references pertaining to the hydrodynamic design of seaplanes have been compiled, and the information is presented in the form of abstracts classified under six main headings.
Aerodynamic characteristics of a wing with quarter-chord line swept back 45 degrees, aspect ratio 6, taper ratio 0.6, and NACA 65A009 airfoil section
From Introduction: "This paper presents the results of the investigation of the wing-alone and wing-fuselage configurations employing a wing with the quarter-chord line swept back 45^o, aspect ratio 4, taper ratio 0.3, and an NACA 65A006 airfoil section parallel to the stream."
Aerodynamic Characteristics of Several Modifications of a 0.45-Scale Model of the Vertical Tail of the Curtiss XP-62 Airplane
"In the course of an investigation to find a satisfactory vertical tail for the XP-62 airplane, a 0.45-scale vertical tail model on a stub fuselage was tested in the Langley 7- by 10-foot tunnel. This model was fitted with a flat plate to represent the horizontal tail surface. The data are presented herein for their general interest value rather than their application to this particular airplane" (p. 1).
Aerodynamic Properties of Slender Wing-Body Combinations at Subsonic, Transonic, and Supersonic Speeds
From Introduction: "In an incomprehensible medium, the mutual interference of a fuselage and wing of high-aspect ratio (to which lifting-line theory is applicable) has been treated by Lennertz, Wiselsberger, Pepper, and Multhopp in reference 1, 2, 3, and 4. It is the purpose of this note to treat the effect of on the aerodynamic loading of the mutual interference between a low-aspect-ratio pointed wing and a fuselage consisting of a slender body of revolution."
Aerodynamic Study of a Wing-Fuselage Combination Employing a Wing Swept Back 63 Degrees: Characteristics for Symmetrical Wing Sections at High Subsonic and Moderate Supersonic Mach Numbers
From Summary: "Results of wind-tunnel tests are presented for a wing with the leading edge swept back 63^o and of symmetrical section in combination with a body at Mach numbers from 0.5 to 0.95 and from 1.09 to 1.51."
Airfoil-Contour Modifications Based on (Epsilon)-Curve Method of Calculating Pressure Distribution
From Introduction: "Certain alternations of a qualitative nature may be performed in spite of the fact that a pressure change cannot be prescribed. It is the purpose of this paper to indicate a method by which qualitative alternation may be performed. It will be noted that the present method of contour modification will serve the intended purpose of the inverse method."
Airspeed Fluctuations as a Measure of Atmospheric Turbulence
"Increments in structural loads due to atmospheric turbulence can be accurately expressed in terms of flight speed and effective gust velocities (reference 4). Data from which the effective gust velocities could be computed were also obtained during the flights of the XC-35 airplane. These data have been used to determine the significance of the fluctuations in the pilot's indicated-airspeed readings in relation to structural loads to due to atmospheric turbulence" (p. 3).
Altitude Performance of AN-F-58 Fuels in British Rolls-Royce Nene Single Combustor
"An investigation was conducted with a single combustor from a British Rolls-Royce Nene turbojet engine to determine the altitude performance characteristics of AN-F-58 fuels. Three fuel blends conforming to AN-F-58 specifications were prepared in order to determine the influence of fuel boiling temperatures and aromatic content on combustion efficiencies and altitude operational limits. The performance of the three AN-F-58 fuels was compared in the range of altitudes from sea level to 65,000 feet, engine speeds from 40- to 100- percent normal rated, and flight Mach numbers of 0.0 and 0.6" (p. 1).
Altitude-Test-Chamber Investigation of a Solar Afterburner on the 24C Engine 1 - Operational Characteristics and Altitude Limits
"An altitude-test-chamber investigation was conducted to determine the operational characteristics and altitude blow-out limits of a Solar afterburner in a 24C engine. At rated engine speed and maximum permissible turbine-discharge temperature, the altitude limit as determined by combustion blow-out occurred as a band of unstable operation of about 8000 feet altitude in width with maximum altitude limits from 32,000 feet at a Mach number of 0.3 to about 42,000 feet at a Mach number of 1.0. The maximum fuel-air ratio of the afterburner, as limited by maximum permissible turbine-discharge gas temperatures at rated engine speed, varied between 0.0295 and 0.0380 over a range of flight Mach numbers from 0.25 to 1.0 and at altitudes of 20,000 and 30,000 feet" (p. 1).
Aluminum-Zinc-Magnesium-Copper Casting Alloys
From Introduction: "This paper contains data on the mechanical properties of sand-cast test bars having a considerable range in zinc, magnesium, and copper content and more detailed data on the properties and foundry characteristics of an aluminum-zinc-magnesium-copper alloy having a preferred composition for high strength and ductility."
Analysis of Heat and Compressibility Effects in Internal Flow Systems and High-Speed Tests of a Ram-Jet System
Report discussing an analysis has been made by the NACA of the effects of heat and compressibility in the flow through the internal systems of aircraft along with equations and charts are developed whereby the flow characteristics at key stations in a typical internal system may be readily obtained.
Analysis of Jet-Propulsion-Engine Combustion-Chamber Pressure Losses
From Summary: "The development and the use of a chart for estimating the pressure losses in jet-engine combustion chambers are described. By means of the chart, the pressure losses due to fluid friction and to momentum changes in the air flow accompanying combustion can be separately evaluated. The over-all pressure losses computed from the pressure-loss chart are within 7 percent of the experimental values for the three types of combustion chambers considered herein."
An analysis of life expectancy of airplane wings in normal cruising flight
From Summary: "The independent variables considered in the analysis included stress-concentration factor, stress-load relation, wing loading, design and cruising speeds, design gust velocity, and airplane size. Several methods for estimating fatigue life from gust frequencies are discussed."
Analysis of propeller efficiency losses associated with heated-air thermal de-icing
From Introduction: "The results of the tests made with unheated internal flow are reported in reference 1. It is the purpose of this paper to attempt to express simply the efficiency loss as a function of the parameters which govern propeller operation and the internal air flow. The derived equations are correlated with the data presented in reference 1."
Analysis of Square Shear Web Above Buckling Load
"A solution of Von Karman's fundamental equations for plates with large deflections is presented for the case of a shear web divided into square panels by reinforcing struts. Numerical solutions are given for struts of infinite rigidity and for struts the weight of which is one-fourth the weight of the sheet. The results are compared with Wagner's diagonal tension theory as extended by Kuhn and by Langhaar. It is found that the diagonal tension theory as developed by Kuhn agrees best with the present paper in the practical range when r=1/4. Kuhn's theory is in especially good agreement for the force in the strut when r=1/4" (p. 1).
An analysis of the main spray characteristics of some full-size multi-engined flying boats
From Introduction: "Because of the importance of spray height, it is the purpose of the work considered in this report to attempt to determine a correlation for the main spray height in relatively smooth water."
Analysis of V-G Records from the SNB-1 Airplane
Availability data obtained on SNB-1 trainer-class airplanes were analyzed and results presented as flight envelopes which predict occurrences of large values of air speed and acceleration. Comparison is made with SNJ-4 trainer-class airplane data analyzed by the same method. It is concluded that flight envelopes are satisfactory; that the two types show large differences in flight loads and speeds experience; and that SNB-1 will seldom, if ever, exceed design limit load factor and restricted speed, which SNJ-4 can be expected to exceed design-limit load factor and restricted speed in a very small number of flight hours.
Analytical Treatment of Normal Condensation Shock
"The condensation of water vapor in an air has the following consequences: acquisition of heat (liberated heat vaporization; loss of mass on the part of the flowing gas (water vapor is converted to liquid); change in the specific gas constants and of the ratio k of the specific heats (caused by change of gas composition). A discontinuous change of state is therefore connected with the condensation; schlieren photographs of supersonic flows in two-dimensional Laval nozzles show two intersecting oblique shock fronts that in the case of high humidities may merge near the point of intersection into one normal shock front" (p. 1).
Applicability of Similarity Principles to Structural Models
"A systematic account is given in part I of the use of dimensional analysis in constructing similarity conditions for models and structures. The analysis covers large deflections, buckling, plastic behavior, and materials with nonlinear stress-strain characteristics, as well as the simpler structural problems" (p. 1).
The application of the statistical theory of extreme values to gust-load problems
From Introduction: "Recent developments in the statistical theory of extreme values (references 4 to 10) have indicated a somewhat more rational approach to the problem of predicting the probability of occurrence The present report summarizes some of these findings, indicates the method of application, and evaluates their applicability to certain gust-load problems ."
Application of Theodorsen's Theory to Propeller Design
"A theoretical analysis is presented for obtaining by use of Theodorsen's propeller theory the load distribution along a propeller radius to give the optimum propeller efficiency for any design condition. Examples are included to illustrate the method of obtaining the optimum load distributions for both single-rotating and dual-rotating propellers" (p. 1).
An approximate method for calculating the effect of surface roughness on the drag of an airplane
From Summary: "A method for computing the effect of surface roughness on the drag coefficient of an airplane is presented. Calculated results using this method are compared with experimental results from both flight and wind-tunnel tests. In general, the agreement is believed satisfactory."
Approximate Method for Predicting Form and Location of Detached Shock Waves Ahead of Plane or Axially Symmetric Bodies
Note presenting an approximate method developed to predict the location of detached shock waves ahead of two-dimensional and axially symmetric bodies. The method is based on the continuity relation, which is applied to the air that passes the sonic line.
Axial Fatigue Test at Two Stress Amplitudes of 0.032-Inch 24S-T Sheet Specimens With a Circular Hole
Report presenting testing of the effect of applying a number of cycles of a high fatigue stress followed by a number of cycles of relatively low stress to failure has been investigated on 93 drilled specimens of a 24S-T sheet. The results indicated that any general formula for endurance must take sequence into consideration, which makes overly simple formulas inadequate to describe endurance over varying stress amplitudes.
Bending With Large Deflection of a Clamped Rectangular Plate With Length-Width Ratio of 1.5 Under Normal Pressure
"The Von Karman equations for a thin flat plate with large deflections are solved for the special case of a plate with clamped edges having a ratio of length to width of 1.5 and loaded by uniform normal pressure. Center deflections, membrane stresses, and extreme-fiber bending stresses are given as a function of pressure for center deflections up to twice the thickness of the plate. For small deflections the results coincide with those obtained by Hencky from the linear theory" (p. 1).
Bibliography of NACA Papers on Rotating-Wing Aircraft, July 1948
"A bibliography of NACA papers on rotating-wing aircraft issued up to July 1948 is presented. The list of papers is subdivided for ready reference under appropriate subject headings, and the titles are listed chronologically within each subject" (p. 1).
Blade Design Data for Axial-Flow Fans and Compressors
Report presenting an investigation to obtain blade design data for high-efficiency axial-flow fans and compressors, which were carried out in a two-dimensional low-speed cascade tunnel. The effects of camber, solidity, and stagger on blade turning angle and the shape of pressure distributions were determined for a family of five low-drag airfoils.
Calculated effects of full-span slotted and Fowler flaps on longitudinal stability and control characteristics for a typical fighter-type airplane with various tail modifications
Report presenting an analytical study of the influence of full-span slotted and Fowler flaps on the requirements for horizontal tail surfaces. The elevator deflection required to land at three-point attitude, elevator deflection required to stall the airplane at altitude, and permissible center-of-gravity range have been calculated for a fighter-type airplane.
Calculation of the Pressure Distribution on Bodies of Revolution in the Subsonic Flow of a Gas Part 1 - Axially Symmetrical Flow
"The present report concerns a method of computing the velocity and pressure distributions on bodies of revolution in axially symmetrical flow in the subsonic range. The differential equation for the velocity potential Phi of a compressible fluid motion is linearized tn the conventional manner, and then put in the form Delta(Phi) = 0 by affine transformation. The quantity Phi represents the velocity potential of a fictitious incompressible flow, for which a constant superposition of sources by sections is secured by a method patterned after von Karman which must comply with the boundary condition delta(phi)/delta(n) = 0 at the originally specified contour" (p. 1).
Calculations of the Dynamic Stress of Several Airplane Wings in Various Gusts
"A series of calculations of the dynamic response of airplane wings to gusts were made with the purpose of showing the relative response of a reference airplane, the DC-3 airplane, and of newer types of airplanes represented by the DC-4, DC-6, and L-49 airplanes. Additional calculations were made for the DC-6 airplane to show the effects of speed and altitude. On the basis of the method of calculation used and the conditions selected for analysis, it is indicated that: 1) The newer airplanes show appreciably greater dynamic stress in gusts then does the reference airplane; 2) Increasing the forward speed or the operating altitude results in an increase of the dynamic stress ratio for the gust with a gradient distance of 10 chords" (p. 1).
Calibrations of pitot-static tubes at high speeds
Report presenting the calibrations of three types of service pitot-static tubes over an approximate range of speeds of 150 to 600 miles per hour. The calibrations indicated a need for a pitot-static tube with greater accuracy, especially at higher speeds. Results regarding the service tubes, Prandtl tube, Eigh-speed tube, and a comparison of the tubes are provided.
Characteristics of Thin Triangular Wings With Constant-Chord Full-Span Control Surfaces at Supersonic Speeds
Note presenting a theoretical analysis of the characteristics of constant-chord full-span control surfaces on thin triangular wings at supersonic speeds by use of methods based on the linearized equation for supersonic flow. Expressions were found for the lift effectiveness, pitching-moment coefficient, hinge-moment coefficient due to control deflection, and hinge-moment coefficient due to angle of attack.
Characteristics of thin triangular wings with constant-chord partial-span control surfaces at supersonic speeds
Report presenting a theoretical analysis of the characteristics of constant-chord partial-span control surfaces on thin triangular wings at supersonic speeds by use of methods based on the linearized theory for supersonic flow. Two cases were treated with the analysis. Results regarding lift coefficient, rolling-moment coefficient, and hinge-moment coefficient due to flap deflection, hinge-moment coefficient due to angle of attack, and the pitching-moment coefficient due to flap lift.
Charts for Determining Preliminary Values of Span-Load, Shear, Bending-Moment, and Accumulated-Torque Distributions of Swept Wings of Various Taper Ratios
Contains charts for use in determining preliminary values of the spanwise-load, shear, bending-moment, and accumulated-torque distributions of swept wings. The charts are based on strip theory and include four aerodynamic-load distributions, two section-moment distributions, and two inertia-load distributions. The taper ratios considered cover the range from 1.0 to 0 and the results are applicable to any angle of sweep.
Charts for the Computation of Equilibrium Composition of Chemical Reactions in the Carbon-Hydrogen-Oxygen-Nitrogen System at Temperatures From 2000° to 5000° Degrees K
Charts are provided for the estimation and progressive adjustment of two independent variables on which the calculations are based. Additional charts are provided for the graphical calculation of the composition.
Charts for the Determination of Supersonic Air Flow Against Inclined Planes and Axially Symmetric Cones
Report presenting a set of charts for the convenient determination of flow conditions behind a shock wave and at the surface of inclined planes and axially symmetric cones located in a uniform frictionless supersonic air stream. Shock angle, static-pressure coefficient, static-pressure ratio, total-pressure ratio, Mach number ratio, and velocity ratio for two-dimensional and conical flow fields are plotted for a range of free-stream Mach numbers.
Charts for the Minimum-Weight Design of 24S-T Aluminum-Alloy Flat Compression Panels With Longitudinal Z-Section Stiffeners
"Design charts are developed for 24S-T aluminum-alloy flat compression panels with longitudinal z-section stiffeners. These charts make possible the design of the lightest panels of this type for a wide range of design requirements. Examples of the use of the charts are given and it is pointed out on the basis of these examples that, over a wide range of design conditions, the maintenance of buckle-free surfaces does not conflict with the achievement of high structural efficiency" (p. 553).
Column and plate compressive strengths of aircraft structural materials: extruded 24S-T aluminum alloy
Report presenting column and plate compressive strengths of extruded 24S-T aluminum alloy determined both within and beyond the elastic range from tests of thin-strip columns and local-instability tests of H-, Z-, and channel-section columns. The tests are part of a research investigation to provide data on the structural strength of various aircraft materials. Results regarding compressive stress-strain curves and column and plate compressive strengths are provided.
Column and Plate Compressive Strengths of Aircraft Structural Materials: Extruded 24S-T Aluminum Alloy
Column and plate compressive strengths of extruded 24S-T aluminum alloy were determined both within and beyond the elastic range from tests of thin-strip columns and local-instability tests of H-, Z-,and channel-section columns. These tests are part of an extensive research investigation to provide data on the' structural strength of various aircraft materials. The results are presented in the form of curves and charts that are suitable for use in the design and analysis of aircraft structures.
Column and plate compressive strengths of aircraft structural materials: extruded 75S-T aluminum alloy
Report presenting column and plate compressive strengths of extruded 75S-T aluminum alloy both within and beyond the elastic range from tests of thin-strip columns and local-instability tests of H-, Z-, and channel-section columns. The tests are part of an extensive research investigation to provide data on the structural strength of various aircraft materials. Results regarding compressive stress-strain curves and column and plate compressive strengths are provided.
Column Strength of Magnesium Alloy AM-57S
Tests were made to determine the column strength of extruded magnesium alloy AM-57S. Column specimens were tested with round ends and with flat ends. It was found that the compressive properties should be used in computations for column strengths rather than the tensile properties because the compressive yield strength was approximately one-half the tensile yield strength. A formula for the column strength of magnesium alloy AM-57S is given.
A comparative study of weights and sizes of flat-plate exhaust-gas-to-air heat exchangers with and without fins
Note presenting analytical comparisons of weights and volumes for flat-plate heat exchangers with the same calculated thermal output and friction pressure drop for three different fin configurations, including no fins, fins in both the air and exhaust gas passages, and fins in the air passages only. Two different heat exchangers were used and compared with predicted weights and volumes.
Comparison between the measured and theoretical span loadings on a moderately swept-forward and a moderately swept-back semispan wing
Report presenting an investigation in the stability tunnel on two semispan swept-wing models to determine experimentally the span-load distributions and to compare the experimental and theoretical results. Lift, drag, pitching moment, and stalling characteristics are provided.
Comparison of sound emission from two-blade, four-blade, and seven-blade propellers
Report presenting measurements of sound pressures for static conditions for two-blade, four-blade, and seven-blade propellers over a range of tip Mach numbers. Results regarding sound pressures and loudness are provided.
Comparison of Structural Efficiencies of Diagonal-Tension Webs and Truss Webs of 24S-T Aluminum Alloy
"A comparison is made of the structural efficiencies of truss webs of 24S-T aluminum alloy with previously published values of the structural efficiencies of diagonal-tension webs of 24S-T aluminum alloy on the basis of identical allowable stresses. It is concluded that the diagonal-tension beam (web and flanges) can usually be built to be a more efficient beam than the truss beam, even though over a small range the web of a Warren truss beam is slightly more efficient than the web of a diagonal-tension beam" (p. 1).
A Comparison of Two Flight-Test Procedures for the Determination of Aileron Control Capabilities of an Airplane
Report presenting a comparison of two flight-test procedures for the determination of the aileron control capabilities of an airplane. The procedures consist of performing rudder-fixed aileron rolls from straight unbanked flight and from steady turning flight. Results regarding rate of roll comparison and sideslip-angle comparison are provided.
Comparison of Vee-Type and Conventional Tail Surfaces in Combination with Fuselage and Wing in the Variable-Density Tunnel
"The pitching and the yawing moments of a vee-type and a conventional type of tail surface were measured. The tests were made in the presence of a fuselage and a wing-fuselage combination in such a way as to determine the moments contributed by the tail surfaces" (p. 1).
Comparison of Water-Load Distributions Obtained during Seaplane Landings with Bureau of Aeronautics Specifications. TED No. NACA 2413
"Bureau of Aeronautics Design Specifications SS-IC-2 for water loads in sheltered water are compared with experimental water loads obtained during a full--scale landing investigation. This investigation was conducted with a JRS-1 flying boat which has a 20 degrees dead-rise V-bottom with a partial chine flare. The range of landing conditions included airspeeds between 88 and 126 feet per second, sinking speeds between 1.6 and 9.1 feet per second, flight angles less than 6 degrees, and trims between 2 degrees and 12 degrees" (p. 1).
Comparisons of Theoretical and Experimental Lift and Pressure Distributions on Airfoils in Cascade
Note presenting comparisons of theoretical and experimental airfoil lift coefficients and pressure distributions made for two cascades of entrance vanes and three cascades of blower blades with NACA 6-series airfoils, and for one cascade of turbine blades. Results regarding the entrance vanes, blower blades, turbine blades, and possibilities of three-dimensional effects are provided.
Compressibility and Heating Effects on Pressure Loss and Cooling of a Baffled Cylinder Barrel
Report presenting testing to obtain experimental confirmation of the effect of air compressibility on cooling and pressure loss of a baffled cylinder barrel and to evaluate various methods of analysis. Testing occurred over a wide range of air flows and density altitudes.
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