National Advisory Committee for Aeronautics (NACA) - 745 Matching Results

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The 1350 F stress-rupture properties of two wrought alloys and three cast alloys
From Summary: "These properties compare favorably with those of the strongest similar alloys previously investigated. However, compared with a 60Cr-25Fe-15Mo alloy, the three cobalt-chronium-nickel cast alloys are inferior. A correlation of NACA and OSRD (Project NRC-8) data is presented, showing the variation of rupture strengths with temperature in the range of 1350^o to 2000^o for alloys."
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.
Acceleration Characteristics of R-3350 Engine Equipped with NACA Injection Impeller
From Summary: "Qualitative investigations have shown that use of the NACA injection impeller with the R-3350 engine increases the inertia of the fuel-injection system and, when the standard fuel-metering system is used, this increase in inertia results in poor engine acceleration characteristics. This investigation was therefore undertaken to determine whether satisfactory acceleration characteristics of the engine equipped with the injection impeller could be obtained by simple modifications to the fuel-monitoring system. The engine was operated with two types of carburetor; namely, a hydraulic-metering carburetor incorporating a vacuum-operated accelerating pump and a direct-metering carburetor having a throttle-actuated accelerating pump."
Acceleration Measurements During Landing in Rough Water of a 1/7-Scale Dynamic Model of Grumman XJR2F-1 Amphibian - Langley Tank Model 212: TED No. NACA 2378
From Summary: "Tests of a 1/7 size model of the Grumman XJR2F-1 amphibian were made in Langley tank no.1 to examine the landing behavior in rough water and to measure the normal and angular accelerations experienced by the model during these landings. All landings were made normal to the direction of wave advance, a condition assumed to produce the greatest accelerations. Wave heights of 4.4 and 8.0 inches (2.5 and 4.7 ft, full size) were used in the tests and the wave lengths were varied between 10 and 50 feet (70 and 350 ft, full size)."
Acceleration Measurements During Landings of a 1/5.5-Size Dynamic Model of the Columbia XJL-1 Amphibian in Smooth Water and in Waves: Langley Tank Model 208M, TED No. NACA 2336
A 1/5.5-size powered dynamic model of the Columbia XJL-1 amphibian was landed in Langley tank no. 1 in smooth water and in oncoming waves of heights from 2.1 feet to 6.4 feet (full-size) and lengths from 50 feet to 264 feet (full-size). The motions and the vertical accelerations of the model were continuously recorded. The greatest vertical acceleration measured during the smooth-water landings was 3.1g.
Aerodynamic Characteristics at High Speeds of Full-Scale Propellers Having Different Shank Designs
From Summary: "Tests of two 10-foot-diameter two-blade propellers which differed only in shank design have been made in the Langley 16-foot high-speed tunnel. The propellers are designated by their blade design numbers, NACA 10-(5)(08)-03, which had aerodynamically efficient airfoil shank sections, and NACA l0-(5)(08)-03R which had thick cylindrical shank sections typical of conventional blades. The propellers mere tested on a 2000-horsepower dynamometer through a range of blade-angles from 20deg to 55deg at various rotational speeds and at airspeeds up to 496 miles per hour. The resultant tip speeds obtained simulate actual flight conditions, and the variation of air-stream Mach number with advance ratio is within the range of full-scale constant-speed propeller operation."
Aerodynamic characteristics at subcritical and supercritical Mach numbers of two airfoil sections having sharp leading edges and extreme rearward positions of maximum thickness
From Introduction: "A 12-percent-chord-thick wedge section and a reversed NACA 0012 section were chosen for these tests as they are representative of sections having no boat tailing and appreciable boat tailing (i.e., blunt and rounded trailing edges, respectively), and the results of this investigation are compared with those obtained from a previous investigation of the NACA 0012 section. Conclusions are drawn regarding the relative merits of the two unconventional sections and the conventional section in transonic speed range."
Aerodynamic characteristics of a 42 degree swept-back wing with aspect ratio 4 and NACA 64(sub 1)-112 airfoil sections at Reynolds numbers from 1,700,000 to 9,500,000
Report discussing testing on a 42 degree swept-back wing to determine its low-speed aerodynamic characteristics in pitch and yaw at high Reynolds numbers. The main effect of increasing the Reynolds number was delayed wing stalling to higher angles of attack. Roughness on the wing leading edge also had a large adverse effect on lift, drag, and pitching-moment characteristics at higher Reynolds numbers.
Aerodynamic characteristics of a 45 degree swept-back wing with aspect ratio of 3.5 and NACA 2S-50(05)-50(05) airfoil sections
From Introduction: "The present paper presents the scale effect on the longitudinal aerodynamic characteristics, the aerodynamic characteristics in yaw, and the tuft studies for 0^o and 3.7^o yaw. The results of the effect of leading-edge and trailing-edge flaps on the aerodynamic characteristics of the wing will be presented in later reports."
Aerodynamic Characteristics of a Number of Modified NACA Four-Digit-Series Airfoil Sections
Theoretical pressure distributions and measured lift, drag, and pitching moment characteristics at three values of Reynolds number are presented for a group of NACA four-digit-series airfoil sections modified for high-speed applications. The effectiveness of flaps applied to these airfoils and the effect of standard leading-edge roughness were also investigated at one value of Reynolds number. Results are also presented of tests of three conventional NACA four-digit-series airfoil sections.
Aerodynamic Characteristics of a Portion of the Horizontal Tail from a Douglas C-74 Airplane with Fabric-Covered Elevators
A Douglas C-74 airplane, during a test dive at about 0.525 Mach number, experienced uncontrollable longitudinal oscillations sufficient to cause shedding of the outer wing panels and the subsequent crash of the airplane. Tests of a section of the horizontal tail plane from a C-74 airplane were conducted in the Ames 16-foot high-speed wind tunnel to investigate the possibility of the tail as a contributing factor to the accident. The results of the investigations of fabric-covered elevators in various conditions of surface deformation are presented in this report.
Aerodynamic Characteristics of Three Deep-Stepped Planing-Tail Flying-Boat Hulls
An investigation was made in the Langley 300 MPH 7- by 10-foot tunnel to determine the aerodynamic characteristics of three deep-stepped planing-tail flying-boat hulls differing only in the amount of step fairing. The hulls were derived by increasing the unfaired step depth of a planing-tail hull of a previous aerodynamic investigation to a depth about 92 percent of the hull beam. Tests were also made on a transverse-stepped hull with an extended afterbody for the purpose of comparison and in order to extend and verify the results of a previous investigation. The investigation indicated that the extended afterbody hull had a minimum drag coefficient about the same as a conventional hull, 0.0066, and an angle-of-attack range for minimum drag coefficient of 0.0057 which was 14 percent less than the transverse stepped hull with extended afterbody; the hulls with step fairing had up to 44 percent less minimum drag coefficient than the transverse-stepped hull, or slightly more drag than a streamlined body having approximately the same length and volume. Longitudinal and lateral instability varied little with step fairing and was about the same as a conventional hull.
Aerodynamic Measurements Made During Navy Investigation of Human Tolerance to Wind Blasts
From Summary: "This report presents the aerodynamic measurements made during a Navy investigation conducted in the Langley 8-foot high speed tunnel to determine the actual human tolerance to wind blasts."
Air-flow behavior over the wing of an XP-51 airplane as indicated by wing-surface tufts at subcritical and supercritical speeds
Report presenting the air-flow behavior over the wing of an XP-51 airplane including photographs of tufts attached to the wing surface and chordwise pressure distributions. A comparison of tuft studies from flight results are compared with results from wind-tunnel testing. Three types of flow were observed: steady flow, unsteady flow, and break-away flow are provided.
Air-Stream Surveys in the Vicinity of the Tail of a 1/8.33-Scale Powered Model of the Republic XF-12 Airplane
"The XF-12 airplane was designed by Republic Aviation Corporation to provide the Army Air Forces with a high performance, photo reconnaissance aircraft. A series of air-stream surveys were made n the vicinity of the empennage of a 1/8.33-scale powered model of the XF-12 airplane in the Langley 19-foot pressure tunnel. Surveys of the vortical-tail region were made through a range of yaw angles of plus or minus 20 degrees at a high and low angle of attack" (p. 1).
Airfoil in sinusoidal motion in a pulsating stream
From Introduction: "In the present paper, under the same lineaeizing assumptions as are made in the derivation in reference 1 but with the explicit consideration and simplification of the form of the wake extending from the rear of the airfoil, the methods of Theodorsen (reference 2) have been extended to obtain the forces on the airfoil not only at a fixed angle of attack but also in arbitrary motion."
Altitude Cooling Investigation of the R-2800-21 Engine in the P-47G Airplane 4 - Engine Cooling-Air Pressure Distribution
"A study of the data obtained in a flight investigation of an R-2800-21 engine in a P-47G airplane was made to determine the effect of the flight variables on the engine cooling-air pressure distribution. The investigation consisted of level flights at altitudes from 5000 to 35,000 feet for the normal range of engine and airplane operation. The data showed that the average engine front pressures ranged from 0.73 to 0.82 of the impact pressure (velocity head). The average engine rear pressures ranged from 0.50 to 0.55 of the impact pressure for closed cowl flaps and from 0.10 to 0.20 for full-open cowl flaps" (p. 1).
Altitude-Wind-Tunnel Investigation of R-4360-18 Power-Plant Installation for XR60 Airplane, 3, Performance of Induction and Exhaust Systems
From Summary: "A study has been made of the performance of the induction and the exhaust systems on the XR60 power-plant installation as part of an investigation conducted in the Cleveland altitude wind tunnel. Altitude flight conditions from 5000 to 30,000 feet were simulated for a range of engine powers from 750 to 3000 brake horsepower."
Altitude-Wind-Tunnel Investigation of the 19B-2, 19B-8 and 19XB-1 Jet- Propulsion Engines: 4 - Analysis of Compressor Performance
Investigations were conducted in the Cleveland altitude wind tunnel to determine the performance and operational characteristics of the 19B-2, 19B-8, and 19XS-1 turbojet engines. One objective was to determine the effect of altitude, flight Mach number, and tail-pipe-nozzle area on the performance characteristics of the six-stage and ten-stage axial-flow compressors of the 19B-8 and 19XB-1 engines, respectively, The data were obtained over a range of simulated altitudes and flight Mach numbers. At each simulated flight condition the engine was run over its full operable range of speeds. Performance characteristics of the 19B-8 and 19XB-1 compressors for the range of operation obtainable in the turboJet-engine installation are presented. Compressor characteristics are presented as functions of air flow corrected to sea-level conditions, compressor Mach number, and compressor load coefficient. For the range of compressor operation investigated, changes in Reynolds number had no measurable effect on the relations among compressor Mach number, corrected air flow, compressor load coefficient, compressor pressure ratio, and compressor efficiency. The operating lines for the 19B-8 compressor lay on the low-air-flow side of the region of maximum compressor efficiency; the 19B-8 compressor operated at higher average pressure coefficients per stage and produced a lower over-all pressure ratio than did the 19XB-1 compressor.
Altitude-Wind-Tunnel Investigation of the 19B-2, 19B-8, and 19XB-1 Jet Propulsion Engines, 4 - Performance and Windmilling Drag Characteristics
The performance characteristics of the 19B-8 and 19XB-1 turbojet engines and the windmilling-drag characteristics of the 19B-6 engine were determined in the Cleveland altitude wind tunnel. The investigations were conducted on the 19B-8 engine at simulated altitudes from 5000 to 25,000 feet with various free-stream ram-pressure ratios and on the 19XB--1 engine at simulated altitudes from 5000 to 30,000 feet with approximately static free-stream conditions.
Altitude-Wind-Tunnel Investigation of the 19B-2, 19B-8, and 19XB-1 Jet-Propulsion Engines. II - Analysis of Turbine Performance of the 19B-8 Engine
Performance characteristics of the turbine in the 19B-8 jet propulsion engine were determined from an investigation of the complete engine in the Cleveland altitude wind tunnel. The investigation covered a range of simulated altitudes from 5000 to 30,000 feet and flight Mach numbers from 0.05 to 0.46 for various tail-cone positions over the entire operable range of engine speeds. The characteristics of the turbine are presented as functions of the total-pressure ratio across the turbine and the turbine speed and the gas flow corrected to NACA standard atmospheric conditions at sea level. The effect of changes in altitude, flight Mach number, and tail-cone position on turbine performance is discussed. The turbine efficiency with the tail cone in varied from a maximum of 80.5 percent to minimum of 75 percent over a range of engine speeds from 7500 to 17,500 rpm at a flight Mach number of 0.055. Turbine efficiency was unaffected by changes in altitude up to 15,000 feet but was a function of tail-cone position and flight Mach number. Decreasing the tail-pipe-nozzle outlet area 21 percent reduced the turbine efficiency between 2 and 4.5 percent. The turbine efficiency increased between 1.5 and 3 percent as the flight Mach number changed from 0.055 to 0.297.
Altitude-wind-tunnel investigation of thrust augmentation of a turbojet engine 3: performance with tail-pipe burning in standard-size tail pipe
From Introduction: "Evaluation of tail-pipe burning in this engine with a larger tail-pipe combustion chamber is discussed in reference 1. Results of investigations on tail-pipe burning in this engine at static sea-level conditions are presented in reference 2. An investigation of thrust augmentation by means of injecting water at the inlet of an axial-flow compressor engine is discussed in reference 3."
Altitude-wind-tunnel investigation of thrust augmentation of a turbojet engine II: performance with water injection at compressor inlet
Report presenting testing of a standard turbojet engine by water injection at the inlet of the axial-flow compressor in the altitude wind tunnel. Engine performance at 7600 rpm was obtained over a wide range of water-air-pressure ratios and ram-pressure ratios. Results regarding the engine-component performance are also provided.
An analysis of airspeeds and Mach numbers attained by Lockheed Constellation airplanes in transcontinental operations during the early summer of 1946
Report presenting airspeed and altitude data obtained from Lockheed Constellation airplanes flying between New York and San Francisco during May and June of 1946 in order to determine the probability of reaching or exceeding given values of airspeed and Mach number. Analysis indicated that the total probability of exceeding the placard "never extend" speed depends primarily on the probability of exceeding this speed in descent. The probability of exceeding the critical Mach number is very negligible.
Analysis of effect of basic design variables on subsonic axial-flow-compressor performance
From Summary: "A blade-element theory for axial-flow compressors has been developed and applied to the analysis of the effects of basic design variables such as Mach number, blade loading, and velocity distribution on compressor performance. The relations among several efficiencies useful in compressor design are derived and discussed. The possible gains in useful operating range obtainable by the use of adjustable stator blades are discussed and a rapid approximate method of calculating blade-angle resettings is shown by an example."
An analysis of longitudinal-control problems encountered in flight at transonic speeds with a jet-propelled airplane
From Introduction: "This report presents an analysis based on flight and wind-tunnel test data directed toward the determination of the probable cause of the pitch-up. Wing pressure distribution and stability and control characteristics in the dive are also included."
Analysis of Performance of Jet Engine From Characteristics of Components 1: Aerodynamic and Matching Characteristics of Turbine Component Determined With Cold Air
Note presenting the performance of the turbine component of a research jet engine investigated with cold air. The interaction and matching of the turbine with the eight-stage compressor were computed with the combination considered as a jet engine and overall performance of the engine was then determined. Results regarding the performance of the first stator ring, turbine performance, and turbine-compressor matching are provided.
Analysis of Performance of Jet Engine From Characteristics of Components 1: Aerodynamic and Matching Characteristics of Turbine Component Determined With Cold Air
"The performance of the turbine component of an NACA research jet engine was investigated with cold air. The interaction and the matching of the turbine with the NACA eight-stage compressor were computed with the combination considered as a jet engine. The over-all performance of the engine was then determined. The internal aerodynamics were studied to the extent of investigating the performance of the first stator ring and its influence on the turbine performance" (p. 397).
An Analysis of the Compressive Strength of Honeycomb Cores for Sandwich Construction
Note presenting an analysis that was undertaken as part of an investigation of low-density fibrous core materials for sandwich construction. This particular investigation found that honeycomb structure exhibit promise as core materials because of their high strength-weight ratios. A formula has been derived that considerably reduced the amount of testing necessary to evaluate the effectiveness of the materials.
An analysis of the factors that affect the exhaust process of a four-stroke-cycle reciprocating engine
From Introduction: "An investigation was made to determine the relative significance of the factors that affect the exhaust process; the effects that an exhaust-process change has on cylinder charging were given special attention. Differential equations of this nature have been developed by Kemble (reference 1) but the forms of these equations are such that general conclusions regarding the various factors affecting the exhaust process cannot be determined."
An Analysis of the Full-Floating Journal Bearing
An analysis of the operating characteristics of a full-floating bearing - a bearing in which a floating sleeve is located between the journal and bearing surfaces - is presented together with charts - from which the performance of such bearings may be predicted. Examples are presented to illustrate the use of these charts and a limited number of experiments conducted upon a glass full-floating bearing to verify some results of the analysis are reported. The floating sleeve can operate over a wide range of speeds for a given shaft speed, the exact value depending principally upon the ratio of clearances and upon the ratio of radii of the bearing. Lower operating temperatures at high rotative speeds are to be expected by using a full-floating bearing. This lower operating temperature would be obtained at the expense of the load-carrying capacity of the bearing if, for comparison, the clearances remain the same in both bearings. A full-floating bearing having the same load capacity as a conventional journal bearing may be designed if decreased clearances are allowable.
An analysis of the full-floating journal bearing
Report discussing an analysis of the operating characteristics of a full-floating journal bearing, a bearing in which a floating sleeve is located between the journal and bearing surfaces, is presented together with charts from which the performance of such bearings may be predicted.
Analysis, Verification, and Application of Equations and Procedures for Design of Exhaust-Pipe Shrouds
Investigations were made to develop a simplified method for designing exhaust-pipe shrouds to provide desired or maximum cooling of exhaust installations. Analysis of heat exchange and pressure drop of an adequate exhaust-pipe shroud system requires equations for predicting design temperatures and pressure drop on cooling air side of system. Present experiments derive such equations for usual straight annular exhaust-pipe shroud systems for both parallel flow and counter flow. Equations and methods presented are believed to be applicable under certain conditions to the design of shrouds for tail pipes of jet engines.
Analytical and experimental investigation of bolted joints
From Introduction: "The present paper contains the development of a recurrence formula for the bolt loads for the simplified case of a symmetrical butt joint with bolts spaced evenly in line with the applied load. The method presented herein is based on the fundamental relationship which was developed in reference 1 between the loads on any two successive bolts. The present paper also gives the results of an experimental investigation conducted to substantiate further the adequacy of the elastic theory as well as to yield additional data on the critical bolt load and the behavior of long joints in the plastic range and at the ultimate load."
Analytical Comparison of a Standard Turbojet Engine, a Turbojet Engine with a Tail-Pipe Burner, and a Ram-Jet Engine
From Introduction: "Experimental investigations (reference 1) have shown that in some cases the thrust can be more than doubled by means of tail-pipe burning. A comparison is made of a standard turbojet engine, whose thrust is augmented by tail-pipe burning, and a ram-jet engine. The performance characteristics for the ram-jet engine were computed entirely from theoretical considerations and on the assumption that the burner-inlet velocity was constant."
An Analytical Investigation of the Heat Losses from a U.S. Navy K-Type Airship
From Summary: "The heat losses from the envelope surface of a U.S. Navy K-type airship are evaluated to determine if the use of heat is a feasible means of preventing ice and snow accumulations on lighter-than-air craft during flight and when moored uncovered. Consideration is given to heat losses in clear air (no liquid water present in the atmosphere) and in probable conditions of icing and snow. The results of the analysis indicate that the amount of heat required in flight to raise the surface temperature of the entire envelope to the extent considered adequate for ice protection, based on experience with tests of heavier-than-air craft, is very large."
Analytical Treatment of Normal Condensation Shock
The condensation of water vapor in an air 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.
An Anaylsis of Control Requirements and Control Parameters for Direct-Coupled Turbojet Engines
"Requirements of an automatic engine control, as affected by engine characteristics, have been analyzed for a direct-coupled turbojet engine. Control parameters for various conditions of engine operation are discussed. A hypothetical engine control is presented to illustrate the use of these parameters. An adjustable speed governor was found to offer a desirable method of over-all engine control. The selection of a minimum value of fuel flow was found to offer a means of preventing unstable burner operation during steady-state operation" (p. 1).
Application of an ultraviolet spectrophotometric method to the estimation of alkylnaphthalenes in 10 experimental jet-propulsion fuels
Report presenting the combustion efficiencies of 10 experimental jet-propulsion fuels that are approximately 200 degrees Fahrenheit cuts of five selected crudes available in large quantities in a turbojet engine combustor at altitude conditions.
The application of high-temperature strain gauges to the measurements of vibratory stresses in gas-turbine buckets
The feasibility of measuring the vibration in the buckets of a gas turbine under service conditions of speed and temperature was determined by use of a high temperature wire strain gauge cemented to a modified supercharger turbine bucket. A high-temperature wire strain gauge and the auxiliary mechanical and electrical equipment developed for the investigation are described.
An application of lifting-surface theory to the prediction of angle-of-attack hinge-moment parameters for aspect ratio 4.5 wings
Report presenting an investigation made of the angle-of-attack-type loading for an elliptical wing of aspect ratio 4.5 in an attempt to augment existing methods of prediction of finite span angle-of-attack hinge-moment parameters.
An Application of Statistical Data in the Development of Gust-Load Criterions
"In conjunction with assumptions concerning the proportion of time spent at various speeds, statistical gust data were used to determine gust load factors that could be exceeded a given number of times during the operational life of an airplane. The results indicated that present gust load factors might be considerably lowered in certain cases with a consequent decrease in structural weight. Modification of the present criterion, however, must await the accumulation of data not presently available" (p. 1).
Application of the analogy between water flow with a free surface and two-dimensional compressible gas flow
From Introduction: "The development of the measuring apparatus and techniques is presented herein. The application of the analogy to flows through nozzles and about circular cylinders at subsonic velocities extending into supercritical range is also presented."
Appreciation and determination of the hydrodynamic qualities of seaplanes
Report presenting a summary of the hydrodynamic qualities of interest in the normal operation of a seaplane, established over a period of years by model testing and by some knowledge of full-size operation. Results regarding longitudinal stability and control, landing stability, seaworthiness, performances, and lateral stability and control are provided.
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."
Axial-flow fan and compressor blade design data on 52.5 degrees stagger and further verification of cascade data by rotor tests
From Summary: "Previous tests of blower-blade sections have been extended by a series of tests at 52.5 degrees stagger. The results of these tests have been combined with the earlier test results and are presented in new blade design charts which supersede those previously presented. An investigation in a test blower over a range of stagger from 44 degrees to 65 degrees has shown that for blades at a solidity of 1.0, the two-dimensional cascade data predict the turning angle to within 1/2 degrees."
Bearing strength of some sand-cast magnesium alloys
Report presenting testing to determine the bearing strength characteristics of some magnesium-alloy sand castings and the relation between those and more commonly determined tensile properties. The primary sand-cast magnesium alloys of interest for aircraft design are AM403, AM260, and AM265. Results of all of the tension, compression, and shear tests are provided in tables.
Bending Stresses Due to Torsion in a Tapered Box Beam
No Description Available.
Boundary-induced upwash for yawed and swept-back wings in closed circular wind tunnels
Report presenting a determination of the tunnel-induced velocities for yawed and swept-back airfoils in a closed circular wind tunnel. Calculations were performed for elemental horseshoe vortices with one tip of the bound vortex on the tunnel axis for a range of yaw angles and bound-vortex lengths.
Boundary-Layer Momentum Equations for Three-Dimensional Flow
Note presenting boundary-layer momentum equations for the three-dimensional flow of a fluid with variable density and viscosity in a form similar to the momentum equation for two-dimensional flow. The momentum equations can be reduced to the forms of the three-dimensional momentum equations that have been given recently by Prandtl for a fluid with constant density and viscosity.