Search Results

The 6-Foot-4-Inch Wind Tunnel at the Washington Navy Yard
Report discussing the 6-foot-4-inch wind tunnel and its auxiliary equipment has proven itself capable of continuous and reliable output of data. The real value of the tunnel will increase as experience is gained in checking the observed tunnel performance against full-scale performance. Such has been the case of the 8- by 8-foot tunnel, and for that reason the comparison in the calibration tests have been presented.
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."
Abnormal grain growth in nickel-base heat-resistant alloys
From Introduction: "The data included in this report for Nimonic 80A alloy, for instance, represent experiments carried out to help clarify a production problem of grain-size control in an alloy which has been extensively used. The general procedure of the investigation was to carry out controlled laboratory experiments on samples of bar stock to find conditions of heating and hot-working which resulted in abnormal grain growth."
Accelerations and bottom pressures measured on a B-24D airplane in a ditching test
From Introduction: "This report presents only that portion of the data from the first ditching which was to be used roughly establish the accelerations experienced by the pilot and the amount of water pressure to which the fuselage structure was subjected during the ditching."
Acoustic radiation from two-dimensional rectangular cutouts in aerodynamic surfaces
From Introduction: "The experiments in high-speed flow showed that an intense, high-frequency acoustic radiation is an essential feature of the problem. Consequently, a study of the acoustic field (involving schlieren observations and frequency and intensity measurements) was undertaken. This report presents the salient features of the study, which was mainly exploratory."
Aerodynamic characteristics and flying qualities of a tailless triangular-wing airplane configuration as obtained from flights of rocket-propelled models at transonic and supersonic speeds
Report discussing a flight investigation of rocket-powered models of a tailless triangular-wing airplane configuration was made through the transonic and low supersonic speed range at the Langley Pilotless Aircraft Research Station at Wallops Island, Va. An analysis of the aerodynamic coefficients, stability derivatives, and flying qualities based on the results obtained from the successful flight tests of three models is presented.
Aerodynamic heating of a thin, unswept, untapered, multiweb, aluminum-alloy wing at Mach numbers up to 2.67 as determined from a free-flight investigation of a rocket-propelled model
From Introduction: "The heat-transfer data calculated from measured temperatures are compared with values calculated by the theory of Van Driest for a flat plate with laminar and turbulent boundary layers. In addition, the heat-transfer data from the flight tests are compared with data obtained from the Langley Structures Research Division of ground tests of an identical wing at a Mach number approximately equal to 1.99 in the pre-flight jet of the Langley Pilotless Aircraft Research Station at Wallops Island, Va. The stream static pressure is maintained at about 1 atmosphere, the free-stream temperature at about 75^o F, and the stagnation temperature at approximately 500 ^o F (ref.1)."
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."
Aerodynamics of slender wings and wing-body combinations having swept trailing edges
From Introduction: "In the present paper, a general method is developed for solving low-aspect-ratio problems involving shed vortex sheets. Both direct and inverse problems are considered. The method is applicable for all planar problems where the velocity boundary conditions can be made homogeneous by differentiation in either the streamwise or the spanwise directions."
Air conditions close to the ground and the effect on airplane landings
This report presents the results of an investigation undertaken to determine the feasibility of making glide landings in gusty air. Wind velocities were measured at several stations between the ground and a height of 51 feet, and flight tests were made to determine the actual influence of gusts on an airplane gliding close to the ground.
Air-consumption parameters for automatic mixture control of aircraft engines
From Introduction: "The purpose of this analysis was to investigate the use of function of intake-manifold temperature and pressure, exhaust back pressure, and engine speed in place of a ventri as a means of measuring engine air consumption and to determine if this function is suitable for automatic mixture control."
Air-Consumption Parameters for Automatic Mixture Control of Aircraft Engines
From Introduction: "The purpose of this analysis was to investigate the use of a function of intake-manifold pressure, exhaust back pressure, intake manifold temperature, and engine speed in place of a venturi as a means of measuring engine air consumption and to determine if this function is suitable for automatic mixture control."
Air propellers in yaw
Report presents the results of tests conducted at Stanford University of a 3-foot model propeller at four pitch settings and at 0 degree, 10 degrees, 20 degrees, and 30 degrees yaw.
Airplane performance, past and present
Report discussing the progress of airplane performance and measured by speed.
Altitude-pressure tables based on the United States standard atmosphere
This report is a revision of the altitude pressure tables of the United States standard atmosphere given in Technical Report No. 246 and the altitude range has been extended from 50,000 to 80,000 feet.
Altitude-wind-tunnel investigation of thrust augmentation of a turbojet engine IV: performance with tail-pipe burning and water injection
From Introduction: "Thrust augmentation of an axial-flow-type turbojet engine by burning fuel in the tail pipe is discussed in references 1 to 3. Thrust augmentation of the same turbojet engine by water injection at the compressor inlet is reported in reference 4."
Altitude-wind-tunnel tests of power-plant installation in jet-propelled fighter
From Introduction: "The research program included clean-up tests (unpublished data) and stability and control tests (reference 1) made in the NACA Langley full-scale tunnel. An investigation of the aerodynamic characteristics of the power-plant installation in the Cleveland altitude wind tunnel is discussed in this report."
Analysis and Calculation by Integral Methods of Laminar Compressible Boundary-Layer With Heat Transfer and With and Without Pressure Gradient
From Introduction: "The purpose of the present report is to present a comprehensive summary of theoretical investigations of comprehensible laminar boundary layers which have been carried out since 1949 at the Polytechnic Institute of Brooklyn under the sponsorship and with the financial assistance of the National Advisory Committee for Aeronautics. The results of these investigations are contained primarily in references 1 to 7."
Analysis of cooling limitations and effect of engine-cooling improvements on level-flight cruising performance of four-engine heavy bomber
From Introduction: "The difficulties experienced in cooling the exhaust-valve seats of the rear-row cylinders have been overcome to a considerable extent by improving the mixture distribution through application of the injection impeller (reference 1) and by augmenting the flow of cooling air to the critical baffles (reference 2). Flight tests of this airplane (reference 3) indicated that the temperatures of exhaust-valve seats on rear-row cylinders were markedly lowered by these modifications and that airplane range, altitude, and gross weight previously limited by these temperatures could be greatly increased."
An Analysis of Pressure Studies and Experimental and Theoretical Downwash and Sidewash Behind Five Pointed-Tip Wings at Supersonic Speeds
The following report covers an investigation that was done to supplement available experimental data on flow fields behind wings of an aircraft at supersonic speeds, as well as to furnish more quantitative information on the choice of the theoretical method for a given configuration and the accuracy to be expected when using such a method.
An Analysis of Ramjet Engines Using Supersonic Combustion
From Introduction: "The concept of supersonic combustion is by no means new, although little work appears to have been published on the subject. For example, an analysis of supersonic combustion to provide lift under a wing is given in reference 1. Reference 2 discusses applications to hypersonic ramjets being studied at the University of Michigan."
An analysis of the airspeeds and normal accelerations of Douglas DC-3 airplanes in commercial transport operation
From Introduction: "The present report is the second prepared to give the results of an analysis of V-G data from commercial transport airplanes. The present report is concerned with an analysis of data obtained with Douglas DC-3 airplanes flying over three transcontinental routes in the United States."
An analysis of the airspeeds and normal accelerations of Martin M-130 airplanes in commercial transport operation
From Introduction: "Acceleration and airspeed data obtained from V-G records collected during commercial transport operations (references 1 and 2) are being analyzed in some detail to determine the flight loads and operating speeds as functions of airplane, route, season, and prewar and wartime operations."
An analysis of the indications of the University of Chicago airborne turbulence indicator in gusty air
From Introduction: "The present report has been prepared to discuss the indications obtained from the University of Chicago turbulence indicator in relation to simultaneous measurement of atmospheric gustiness made by the NACA, which are summarized herein."
An Analysis of the Transition of a Helicopter From Hovering to Steady Autorotative Vertical Descent
"This report is the second phase of a broad program of study of the transient motions of helicopters in autorotative flight. The first phase (reference 1) dealt with the steady-state condition of autorotative vertical descent. This report is concerned with the the transition from the steady condition of hovering to the steady autorotative descent" (p. 1).
Analysis of the Ultimate Strength and Optimum Proportions of Multiweb Wing Structures
From Introduction: "The results are presented in the form of a structural-efficiency chart where minimum structural weight is plotted as a function of the structural index for constant values of the ratio of wing depth to skin thickness."
An Analysis of the Variation With Altitude of Effective Gust Velocity in Convective-Type Clouds
From Introduction: "In the present paper, the variation of effective gust velocity in convective-type clouds with altitude is investigated. Data obtained during 1941 and 1942 at altitudes up to 34,000 feet and data obtained more recently from the Thunderstorm Project (reference 5) at altitudes up to 26,000 feet are utilized for this purpose. Consideration is given in analyzing the results both to data for the range
Analysis of variation of piston temperature with piston dimensions and undercrown cooling
From Summary: "A theoretical analysis is presented that permits estimation of the changes in piston-temperature distribution induced by variations in the crown thickness, the ring-groove-pad thickness, and the undercrown surface heat-transfer coefficient. The analysis consists of the calculation of operating temperatures at various points in the piston body on the basis of the experimentally determined surface heat-transfer coefficients and boundary-region temperatures, as well as arbitrarily selected surface coefficients."
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."
Analytical investigation of acceleration restriction in a fighter airplane with an automatic control system
From Introduction: "In the present report, consideration is given to certain features intended to improve the accleration-limiting characteristics of a normal-accleration control system."
An analytical investigation of airplane spin-recovery motion by use of rotary-balance aerodynamic data
From Introduction: "Many investigations have been made in the Langley 20-foot free-spinning tunnel in which the natures of airplane spins and recoveries have been determined experimentally with dynamically scaled-down models. The results of some of these investigations are presented in references 1 to 5."
An Analytical Investigation of the Effect of the Rate of Increase of Turbulent Kinetic Energy in the Stream Direction on the Development of Turbulent Boundary Layers in Adverse Pressure Gradients
"The purpose of this paper is to provide a derivation of the general integral form of the boundary equation without neglecting the Reynolds normal-stress term. Two special cases of this equation are given explicitly" (p. 2).
An analytical study of the effect of airplane wake on the lateral dispersion of aerial sprays
From the Introduction: "In the present reports the paths of liquid spray droplets issued in the flow field behind an airplane are calculated."
Antiknock Effectiveness of Xylidines in Small-Scale Engines
"The data presented in this report are part of a general program to determine the effects of xylidines on the knock-limited performance of currently used aviation fuels" (p. 2).
An apparatus for measuring rates of discharge of a fuel-injection system
From Introduction: "An apparatus that gives a quick and an accurate measurement of the rate of discharge has been has been designed by the NACA and is described in this report."
Apparent Effect of Inlet Temperature on Adiabatic Efficiency of Centrifugal Compressors
From Introduction: "The results of varying only Reynolds number for several equivalent tip speeds are presented and probable reasons for the apparent variation of adiabatic efficiency with inlet temperature are discussed."
The appearance of a boric oxide exhaust cloud from a turbojet engine operating on trimethylborate fuel
From Summary: "Data are included on the amount of fallout from the cloud and the concentration of boric oxide in the cloud."
Application of a Windshield-Display System to the Low-Altitude Bombing Problem
From Introduction: "The design and flight evaluation of an airborne target simulator for use in tracking studies of fighter-type airplanes equipped with optical gunsights have recently been reported (ref. 1). In this equipment the target airplane was represented by a movable dot of light projected on the windshield of the test airplane."
Compressive Strength of Tapered Airplane Struts
Note presenting methods for ascertaining the value of n in Euler's simplified formula, which can be used for the compressive strength of tapered airplane struts, by estimating from curves and by calculation.
The Compressive Yield Strength of Extruded Shapes of 24ST Aluminum Alloy
The following report discusses an investigation that was made to determine the tensile and the compressive properties of a large number of 24ST extruded shapes selected at random from commercial production in order to investigate the interrelation of these properties.
Effect of the Reversal of Air Flow Upon the Discharge Coefficient of Durley Orifices
Note presenting an experiment to obtain information regarding the relationship between the coefficients for flow in the two directions through an inlet. The results indicate that the ratio of the orifice discharge coefficient from standard orifice to the discharge coefficient from reverse flow is always less than unity, but approaches unity with increasing ratio of box area to orifice area, and that even for a ratio of areas as low as twenty the ratios of the coefficients is not much less than unity.
The Elastic Constants for Wrought Aluminum Alloys
"There are several constants which have been devised as numerical representations of the behavior of metals under the action of loadings which stress the metal within the range of elastic action. Some of these constants, such as Young's modulus of elasticity in tension and compression, shearing modulus of elasticity, and Poisson's ratio, are regularly used in engineering calculations. Precise tests and experience indicate that these elastic constants are practically unaffected by many of the factors which influence the other mechanical properties of materials and that a few careful determinations under properly controlled conditions are more useful and reliable than many determinations made under less favorable conditions" (p. 1).
Evaluation of Gust and Draft Velocities From Flights of an AT-6 Airplane Within Cumulus Clouds July 1, 1947 to July 22, 1947 at Clinton County Army Air Field, Ohio
Memorandum presenting measurements of gust and draft velocities within cumulus clouds at a certain army air field using an AT-6 airplane. The measurements were made to supplement the at a obtained with P-61C airplanes. The data are summarized in tables.
Evaluation of Gust and Draft Velocities from Flights of F-61C Airplanes within Thunderstorms August 7, 1947 to August 13, 1947 at Clinton County Army Air Field, Ohio
The gust and draft velocities from records of NACA instruments installed in P-61C airplanes participating in thunderstorm flights at Clinton County Army Air FIeld, Ohio, from August 7, 1947 to August 13, 1947 are presented.
Evaluation of Gust and Draft Velocities from Flights of P-61c Airplanes within Thunderstorms 2 - July 9, 1946 to July 11, 1946 at Orlando, Florida
"The results obtained from an evaluation for gust and draft velocities of acceleration and airspeed-altitude records taken by NACA recording instruments installed in P-61c airplanes participating in thunderstorm flights 6, 7, and 8 of July 9, 1946, July 10, 1946, and July 11, 1946, respectively, are presented herein. These data are summarized in tables I and II. In accordance with a recent discussion with a member of the U.S. Weather Bureau staff, the tabulated results for the present flight include in addition to data of the type presented in reference 1, the initial heading of the airplane for each traverse, the pressure altitude at the start of each traverse in increments of 500 feet, and the gust gradient distance when it could be evaluated" (p. 1).
Evaluation of Gust and Draft Velocities from Flights of P-61c Airplanes within Thunderstorms August 7, 1946 to August 13, 1946 at Orlando, Florida
This report presents the results obtained from gust and draft velocity measurements within thunderstorms for the period August 7, 1946 to August, 13, 1946 at Orlando Florida. In several of the surveys, indications of ambient air temperature were obtained from photo-observer records. These data are summarized in the report.
Evaluation of Gust and Draft Velocities from Flights of P-61C Airplanes within Thunderstorms August 16, 1947 to August 20, 1947 at Clinton County Army Air Field, Ohio
The gust and draft velocities from records of NACA instruments installed in P-61C airplanes participating in thunderstorm flights at Clinton County Army Air Field, Ohio, from August 16, 1947 to August 20, 1947 are presented.
Evaluation of Gust and Draft Velocities from Flights of P-61C Airplanes within Thunderstorms July 12, 1947 to July 18, 1947 at Clinton County Army Air Field, Ohio
The gust and draft velocities from records of NACA instruments installed in P-61c airplanes participating in thunderstorm flights at Clinton County Army Air Field, Ohio, from July 12, to July 18, 1947 are presented.
Evaluation of Gust and Draft Velocities from Flights of P-61C Airplanes within Thunderstorms July 24, 1946 to August 6, 1946 at Orlando, Florida
The results obtained from gust and draft velocity measurements within thunderstorms for the period July 24, 1946 to August 6, 1946 at Orlando, Florida are presented herein. These data are summarized in tables I and II and are of the type presented in reference 1 for previous flights. In two thunderstorm traverses, indications of ambient-air temperature were obtained from photo-observer records. These data are summarized in table III.
Evaluation of Gust and Draft Velocities from Flights of P-61C Airplanes within Thunderstorms June 2, 1947 to June 7, 1947 at Clinton County Army Air Field, Ohio
The gust and draft velocities from records of NACA instruments installed in P-61C airplanes participating in thunderstorm flights at Clinton County Army Air Field, Ohio, from June 2, 1947 to June 7, 1947, are presented.
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