National Advisory Committee for Aeronautics (NACA) - 743 Matching Results
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- Buckling Stresses of Simply Supported Rectangular Flat Plates in Shear
- "The present paper evaluates the shear buckling stresses of rectangular flat plates with simply supported edges more accurately than previous work on this problem. Both symmetric (odd number of buckles) and antisymmetric (even number of buckles) patterns were considered. A curve is presented from which the critical stresses may be obtained when the dimensions of the plate are known" (p. 1).
- Buffeting of External Fuel Tanks at High Speeds on a Gruman F7F-3 Airplane
- Attempts were made to alleviate the buffeting of external fuel tanks mounted under the wings of a twin-engine Navy fighter airplane. The Mach number at which buffeting began was increased from 0,529 to 0.640 by streamlining the sway braces and by increasing the lateral rigidity of the sway brace system. Further increase of the Mach number, at which buffeting began to 0.725, was obtained by moving the external fuel tank to a position under the fuselage.
- Buffeting of External Fuel Tanks at High Speeds on a Grumman F7F-3 Airplane
- Attempts were made to alleviate the buffeting of external fuel tanks mounted under the wings of a twin-engine Navy fighter plane. The Mach number at which the buffeting began was increased from 0.529 to 0.640 by streamlining the sway braces and increasing the lateral rigidity of the sway brace system. Further increases of the Mach number, at which buffeting began to 0.725, was obtained by moving the external fuel tank to a position under the fuselage.
- Calculation of compressible flows past aerodynamic shapes by use of the streamline curvature
- "A simple approximate method is given for the calculation of isentropic irrotational flows past symmetrical airfoils, including mixed subsonic-supersonic flows. The method is based on the choice of suitable values for the streamline curvature in the flow field and the subsequent integration of the equations of motion. The method yields limiting solutions for potential flow. The effect of circulation is considered" (p. 1).
- The Calculation of Compressible Flows with Local Regions of Supersonic Velocity
- This report addresses a method for the approximate calculation of compressible flows about profiles with local regions of supersonic velocity. The flow around a slender profile is treated as an example.
- The calculation of drag for airfoil sections and bodies of revolution at subcritical speeds
- Report presenting a method for calculating the drag, in a real compressible fluid and at subcritical Mach numbers, of airfoil sections at arbitrary life coefficients and of bodies of revolution at zero angle of attack. The values of drag coefficient are compared with values obtained for the same configurations by other methods. The differences between the results are found to lie withint he limits of accuracy of current experimental techniques.
- The Calculation of the Heat Required for Wing Thermal Ice Prevention in Specified Icing Conditions
- Note presenting a verification of previously derived equations for calculating the rate of heat transfer from airfoils in icing conditions, which have come about as a result of an investigation of the meteorological conditions conducive to the formation of ice on aircraft and a study of the process of airfoil thermal ice prevention. The results indicated that knowledge of these components has increased to a point where the design of heated wings on a fundamental, wet-air basis can now be undertaken with reasonable certainty.
- 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).
- Calculation of Wing Bending Moments and Tail Loads Resulting from the Jettison of Wing Tips During a Symmetrical Pull-Up
- "A preliminary analytical investigation was made to determine the feasibility of the basic idea of controlled failure points as safety valves for the primary airplane structure. The present analysis considers the possibilities of the breakable wing tip which, in failing as a weak link, would relieve the bending moments on the wing structure. The analysis was carried out by computing the time histories of the wing and stabilizer angle of attack in a 10g pull-up for an XF8F airplane with tips fixed and comparing the results with those for the same maneuver, that is, elevator motion but with tips jettisoned at 8g" (p. 1).
- Calculations and Experimental Investigations on the Feed-Power Requirement of Airplanes With Boundary-Layer Control
- "Calculations and test results are given about the feed-power requirement of airplanes with boundary-layer control. Curves and formulas for the rough estimate of pressure-loss and feed-power requirement are set up for the investigated arrangements which differ structurally and aerodynamically. According to these results the feed power for three different designs is calculated at the end of the report" (p. 1).
- Calculations of the supersonic wave drag of nonlifting wings with arbitrary sweepback and aspect ratio : wings swept behind the Mach lines
- Report presenting calculations of the supersonic wave drag at zero lift for a series of wings with thin symmetrical biconvex sections with untapered plan forms and various angles of sweepback and aspect ratios.
- Calculations of the Supersonic Wave Drag of Nonlifting Wings with Arbitrary Sweepback and Aspect Ratio: Wings Swept Behind the Mach Lines
- "On the basis of a recently developed theory for finite sweptback wings at supersonic speeds, calculations of the supersonic wave drag at zero lift were made for a series of wings having thin symmetrical biconvex sections with untapered plan forms and various angles of sweepback and aspect ratios. The results are presented in a unified form so that a single chart permits the direct determination of the wave drag for this family of airfoils for an extensive range of aspect ratio and sweepback angle for stream Mach numbers up to a value corresponding to that at which the Mach line coincides with the wing leading edge. The calculations showed that in general the wave-drag coefficient decreased with increasing sweepback" (p. 1).
- Calibration and Measurement in Turbulence Research by the Hot-Wire Method
- "The problem of turbulence in aerodynamics is at present being attacked both theoretically and experimentally. In view of the fact however that purely theoretical considerations have not thus far led to satisfactory results the experimental treatment of the problem is of great importance. Among the different measuring procedures the hot wire methods are so far recognized as the most suitable for investigating the turbulence structure" (p. 1).
- Canopy loads investigation for the F6F-3 airplane
- Report presenting an investigation of surface static pressures over the outer and inner surfaces of the cockpit canopies on the Grumman F6F-3, Curtiss SB2C-4E, and Grumman F8F-1 airplanes in the full-scale tunnel. Results regarding the external pressure distribution and internal static pressure are provided.
- Changes Found on Run-in and Scuffed Surfaces of Steel Chrome Plate, and Cast Iron
- Note presenting a study of run-in and scuffed steel, chrome-plate, and cast-iron surfaces. X-ray and electronic diffraction techniques, micro-hardness determinations, and microscopy were used. The surface changes varied and wer efound to include three classes: chemical reaction, hardening, and crystallite-size alteration.
- Characteristics of a 15-Percent-Chord and a 35-Percent-Chord Plain Flap on the NACA 0006 Airfoil Section at High Subsonic Speeds
- Memorandum presenting wind-tunnel tests to determine the aerodynamic characteristics of a 15-percent- and a 35-percent-chord plain trailing-edge flap on the NACA 0006 airfoil section. Simultaneous measurements of section lift, drag, and pitching moment were made over a range of Mach numbers, angles of attack, and flap deflections.
- Charts for determining the characteristics of sharp-nose airfoils in two-dimensional flow at supersonic speeds
- Solutions of the Hugoniot shock equations and Meyer expansion equations are plotted in such a manner as to permit the pressure distribution, the local Mach number, and the angles of shock waves on arbitrary sharp-nose airfoils at supersonic speeds to be obtained directly. (author).
- Charts for stress analysis of reinforced circular cylinders under lateral loads
- Report presenting charts with coefficients for the stress analysis of a reinforced circular cylinder. They allow for the rapid determination of sheer flows and direct stresses in the sheet of a cylinder as well as the shear forces, axial forces, and bending moments in the rings. Separate charts are also given for three basic ring loadings.
- 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 Multiweb Wings in Bending
- Report presenting a method for the calculation of the buckling stress of a multiweb wing in bending as well as design charts based on this method for the minimum-weight design of 24S-T aluminum alloy sheets, extruded 75S-T aluminum alloy, and extruded 0-1HTA magnesium alloy. An example of the use of the charts is also provided.
- Charts Showing Relations Among Primary Aerodynamic Variables for Helicopter-Performance Estimation
- "In order to facilitate solutions of the general problem of helicopter selection, the aerodynamic performance of rotors is presented in the form of charts showing relations between primary design and performance variables. By the use of conventional helicopter theory, certain variables are plotted and other variables are considered fixed. Charts constructed in such a manner show typical results, trends, and limits of helicopter performance" (p. 1).
- Coefficient of Friction, Oil Flow and Heat Balance of a Full-Journal Bearing
- Memorandum presenting the coefficient of friction, oil flow, and heat balance of a full-journal bearing.
- Collection and Analysis of Hinge-Moment Data on Control-Surface Tabs
- Report presenting an analysis of wind-tunnel data on the hinge-moment characteristics of control-surface tabs. Results regarding the correlation of section data, correlation of finite-span data, and effect of Mach number are provided.
- Collection and analysis of wind-tunnel data on the characteristics of isolated tail surfaces with and without end plates
- Report presenting the aerodynamic characteristics of 19 isolated tail surfaces, which have been determined by wind tunnel tests. Testing was also made of rectangular airfoils of various aspect ratios with and without double end plates of various shapes. The analysis indicated that the slope of the lift curve could be predicted within 10 percent for all models by use of lifting-surface-theory equations.
- A collection of the collapsed results of general tank tests of miscellaneous flying-boat-hull models
- Presented here are the summary charts of the collapsed results of general tank tests of about 100 flying boat hull models. These summary charts are intended to be used as an engineering tool to enable a flying boat designer to grasp more quickly the significance of various hull form parameters as they influence his particular airplane. The form in which the charts are prepared is discussed in some detail in order to make them clearer to the designer. This is a data report, and no attempt has been made to produce conclusions or correlations of the usual sort. However, some generalizations are put forward on the various methods in which summary charts may be used.
- Column and Plate Compressive Strengths of Aircraft Structural Materials: Extruded 0-1HTA Magnesium Alloy
- Column and plate compressive strengths of extruded 0-1HTA magnesium alloy were determined both within and beyond the elastic range from tests of flat end H-section columns and from 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.
- The Combination of Internal-Combustion Engine and Gas Turbine
- "While the gas turbine by itself has been applied in particular cases for power generation and is in a state of promising development in this field, it has already met with considerable success in two cases when used as an exhaust turbine in connection with a centrifugal compressor, namely, in the supercharging of combustion engines and in the Velox process, which is of particular application for furnaces. In the present paper the most important possibilities of combining a combustion engine with a gas turbine are considered. These "combination engines " are compared with the simple gas turbine on whose state of development a brief review will first be given" (p. 1).
- Combustion-efficiency investigation of special fuels in single tubular-type combustor at simulated altitude conditions
- Report presenting a combustion-efficiency investigation of 10 special straight-run distillate fuels in an individual tubular-type combustor unit of a 14-unit assembly at two simulated engine operating conditions. These distillates were obtained from various crude oils and consisted of hydrocarbon mixtures with distillations temperature varying from 93 to 690 degrees Fahrenheit. Comparison of temperature measurements obtained from two locations in the exhaust duct showed that under certain operating conditions the flame extended beyond the turbine position.
- Comparative Drag Measurements at Transonic Speeds of 6-Percent-Thick Airfoils of Symmetrical Double-Wedge and Circular-Arc Sections From Tests by the NACA Wing-Flow Method
- Report presenting comparative drag measurements at zero lift at transonic speeds for two sharp-leading-edge airfoils using the NACA wing-flow method. One airfoil had a symmetrical circular-arc section and one had a symmetrical double-wedge section. The primary difference in the drag characteristics of the two airfoils at zero lift is the earlier drag rise of the double-wedge section.
- Comparative Drag Measurements at Transonic Speeds of an NACA 65-006 Airfoil and a Symmetrical Circular-Arc Airfoil
- Report presenting measurements made at transonic speeds by the freely-falling-body method to compare the drag of a rectangular plan-form airfoil of aspect ratio 7.6 with an NACA 65-006 airfoil section. Results regarding the velocity measurements, base-pressure measurements, and airfoil drag measurements are provided.
- Comparative performance of two vaneless diffusers designed with different rates of passage curvature for mixed-flow impellers
- Report presenting an investigation of the effect of diffuser performance of the passage curvature of two vaneless diffusers designed with a 6 degree equivalent-cone divergence angle along a logarithmic-spiral path in combination with two mixed-flow impellers. The peak of overall adiabatic efficiency is compared with the corresponding diffuser efficiency. Results regarding the variation of diffuser efficiency with load-coefficient parameter and peak overall adiabatic efficiencies and corresponding diffuser efficiencies of the two compressors are provided.
- 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.
- Comparative Tests on Extruded 14S-T and Extruded 24S-T Hat-Shape Stiffener Sections
- Note presenting an investigation to compare the 14S-T with 24S-T in extruded stiffeners for stiffened flat sheet panels. The tests were made with stiffened flat sheet panels with three hat-shape stiffeners. Data is provided on the strength of the two alloys as well as the effect of sheet thickness on relative stiffener strengths.
- Comparison between flight-measured and calculated span load distribution at high Mach numbers
- Report presenting an analysis of the spanwise loading using two different methods on the wing of an airplane for which pressure-distribution measurements were available from flight tests up to a Mach number of 0.866. A comparison between measured and calculated distributions was made on the basis of equal wing-panel normal-force coefficients.
- 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 Crystal Structures of 10 Wrought Heat Resisting Alloys at Elevated Temperatures With Their Crystal Structures at Room Temperatures
- Note presenting an investigation to compare the crystal structure of the predominant phase at temperatures of 1200, 1500, and 1800 degrees Fahrenheit in 10 wrought heat-resisting alloys with crystal structure observed at room temperature. The alloys investigated included S-816, S-590, Hastelloy B, 19-9 W-Mo, N-155, 16-25-6, K-42-B, Inconel X, Nimonic 80, and type 347 stainless steel.
- Comparison of design specifications with the actual static transverse stability of 25 seaplanes
- Report presenting a comparison of the maximum amount of transverse righting moment at rest provided by auxiliary floats or stub wings for 25 seaplanes and the minimum righting moment required by certain design specifications. Large differences were found to exist between the specifications and 25 designs studied.
- A comparison of flight test results on a scout-bomber airplane with 4.7 degree and with 10 degree geometric dihedral in the wing outer panels
- Report presenting a flight investigation of a scout-bomber airplane with 4.7 degrees and 10 degree geometric dihedral in the wing outer panels in order to obtain flight test results pertaining to the upper limit of the wing-dihedral angle for satisfactory handling qualities. No unusual or undesirable lateral control characteristics were observed with the combinations of stability parameters obtained with the two dihedral angles used.
- 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 the control-force characteristics of two types of lateral-control system for large airplanes
- Report presenting an analysis of wind-tunnel data for two types of lateral-control system for large airplanes in order to determine the control-force characteristics and rolling effectiveness of each system. The two types of control systems explored are a spring-tab aileron and a combination spoiler and guide or pilot-aileron arrangement.
- A Comparison of the Lateral Motion Calculated for Tailless and Conventional Airplanes
- Theoretical analysts of lateral dynamic motion of tailless and conventional airplanes was made for fighter and heavy transport. Their reactions to a lateral gust and control power required by each for simple maneuvers were determined and compared. Both types of airplanes require almost identical aileron control power to perform a given maneuver; tailless airplane requires about 1-2 to 1-3 directional control power of conventional airplane. Tailless airplane also shows greatest displacement for a given disturbance and has least damping in oscillatory mode.
- Comparison of the transonic drag characteristics of two wing-body combinations differing only in the location of the 45 degree sweptback wing
- Report presenting the drag of a series of wing-body combinations by the free-fall method in order to provide information on the drag characteristics of promising transonic and supersonic airplane arrangements. Time histories, Mach number variations, and drag coefficients for several areas of the body are provided.
- A comparison of three theoretical methods of calculating span load distribution on swept wings
- Report presenting the application of three methods for calculating span load distribution for five swept wings. The methods were examined to establish their relative accuracy and ease of application. While the Weissinger and Falkner methods were more useful for certain circumstances, there were no advantages noted with the Mutterperl method.
- A comparison of three theoretical methods of calculating span load distribution on swept wings
- From Summary: "Three methods for calculating span load distribution, those developed by V.M Falkner, Wm. Mutterperl, and J. Weissinger, have been applied to five swept wings. The angles of sweep ranged from -45 degrees to +45 degrees. These methods were examined to establish their relative accuracy and case of application. Experimentally determined loadings were used as a basis for judging accuracy. For the convenience of the readers the computing forms and all information requisite to their application are included in appendixes. From the analysis it was found that the Weissinger method would be best suited to an over-all study of the effects of plan form on the span loading and associated characteristics of wings."
- Comparison of Wind-Tunnel Predictions with Flight Measurements of the Longitudinal-Stability and -Control Characteristics of a Douglas BTD-1 Airplane
- "Low Mach number longitudinal-stability and control characteristics as predicted by use of wind tunnel data from a powered 3/16-scale model are compared with flight test measurements of a Navy BTD-1 airplane. The accuracy of the wind tunnel data and the discrepancies involved in attempting to correlate with flight data are discussed and analyzed. The comparison showed that wind tunnel predictions were, in general, in good agreement with flight test data" (p. 1).
- A comparison with flight data of vertical-tail loads in various maneuvers estimated from sideslip angles and rudder deflections
- Report presenting a comparison of the vertical-tail loads determined from pressure-distribution measurements in flight in various maneuvers with the corresponding vertical-tail loads. Some of the maneuvers investigated included slow rolls, steady sideslips, fishtails, and rolling pull-outs.
- 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.
- Compilation of Test Data on 111 Free-Spinning Airplane Models Tested in the Langley 15-Foot and 20-Foot Free-Spinning Tunnels
- "A compilation of free-spinning-airplane model data on the spin and recovery characteristics of 111 airplanes is presented. These data were previously published in separate memorandum reports and were obtained from free-spinning tests in the Langley 15-foot and the Langley 20-foot free-spinning tunnels. The model test data presented include the steady-spin and recovery characteristics of each model for various combinations of aileron and elevator deflections and for various loadings and dimensional configurations" (p. 1).
- Compressible Flow Tables for Air
- "This paper contains a tabulation of functions of the Mach number which are frequently used in high-speed aerodynamics. The tables extend from M = 0 to M = 10.0 in increments of 0.01 and are based on the assumption that air is a perfect gas having a specific heat ratio of 1.400" (p. 1).
- Compression Shocks of Detached Flow
- "It is known that compression shocks which lead from supersonic to subsonic velocity cause the flow to separate on impact on a rigid wall. Such shocks appear at bodies with circular symmetry or wing profiles on locally exceeding sonic velocity, and in Laval nozzles with too high a back pressure. The form of the compression shocks observed therein is investigated" (p. 1).