National Advisory Committee for Aeronautics (NACA) - 4,107 Matching Results

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Alterations and Tests of The "Farnboro" Engine Indicator
"The 'Farnboro' electric indicator was tested as received from the manufacturers, and modifications made to the instrument to improve its operation. The original design of disk valve was altered so as to reduce the mass, travel, and seat area. Changes were made to the recording mechanism, which included a new method of locating the top center position on the record. The effect of friction on the motion of the pointer while taking motoring and power cards was eliminated by providing a means of putting pressure lines on the record" (p. 1).
An Altitude Chamber for the Study and Calibration of Aeronautical Instruments
"The design and construction of an altitude chamber, in which both pressure and temperature can be varied independently, was carried out by the NACA at the Langley Memorial Aeronautical Laboratory for the purpose of studying the effects of temperature and pressure on aeronautical research instruments. Temperatures from +20c to -50c are obtained by the expansion of CO2from standard containers. The chamber can be used for the calibration of research instruments under altitude conditions simulating those up to 45,000 feet" (p. 1).
Ambient Pressure Determination at High Altitudes by Use of Free-Molecule Theory
"Several methods (references 1 and 2) based on gas-dynamic principles are available for reducing such measurements. The results obtained by these methods are subject to the limitation of the gas-dynamic theory which is that the mean free path of the molecules between impacts, is small with respect to the measuring device. Inasmuch as no information on the subject is to present known to be available, the purpose of the present paper is to present a method based on the concept of free-molecule theory for use in connection with this problem" (p. 1).
The Ames 10- by 14-Inch Supersonic Wind Tunnel
"The purpose of the present report is to describe the 10- by 14-inch supersonic wind tunnel and its operational characteristics over the nominal Mach number range from 2.7 to 6.3. Rather complete calibration data on characteristics of flow in the test section are presented and briefly discussed" (p. 2).
Amplitude of Supersonic Diffuser Flow Pulsations
From Introduction: "This report, prepared at the NACA Lewis laboratory, presents a theoretical evaluation of the variables which govern pulsation amplitude for the cold-flow engine."
Analogue-computer simulation of an autopilot servo system having nonlinear response characteristics
From Introduction: "The servo system considered in this report is in the latter category, due mainly to the fact its amplifier tends to saturate. An investigation of the longitudinal dynamic response of the stabilized airplane was made and the results were reported in reference 1. In this investigation it was found that when restricted to linear methods of analysis the performance of the autopilot-aircraft combination could be predicted for only the small range of operation where the elements of the autopilot operated within their linear range."
Analogy Between Mass and Heat Transfer with Turbulent Flow
From Introduction: "The purpose of this paper is to present an analysis of the mass- and heat-transfer process in terms of a simplified physical picture of the turbulent boundary layer subject to the assumptions previously described."
Analysis and comparison with theory of flow-field measurements near a lifting rotor in the Langley full-scale tunnel
From Introduction: "The time-averaged flows are considerably simpler to deal with theoretically than are the instantaneous flows, and the results of several theoretical analyses are available (refs. 2 to 6, for example). Several previous experimental investigations (see ref. 7 for a bibliography) have provided some qualitative information on the subject by the use of smoke in flight and in wind tunnels. However, quantitative measurements (refs. 8 to 10) are extremely scarce and, in general, are inadequate either to define the nature of the flow or to check the accuracy of the theoretical calculations."
Analysis and Model Tests of Autogiro Jump Take-Off
From Introduction: "The possibilities of the jump take-off have been established by some full-scale experiments. It is the purpose of this paper to study the factors that govern the jump take-off in its simplest form and to present the results of model tests in which the effect of differences in the rotor parameters was determined."
Analysis and modification of theory for impact of seaplanes on water
From Summary: "An analysis of available theory on seaplane impact and a proposed modification thereto are presented."
Analysis and Preliminary Design of an Optical Instrument for the Measurement of Drop Size and Free-Water Content of Clouds
From Summary: "This paper describes a method for the determination of drop size and free water in clouds, based on the interpretation of an artificially created rainbow. Details of the design and operation of an optical instrument employing this method are presented."
Analysis for Control Application of Dynamic Characteristics of Turbojet Engine With Tail-Pipe Burning
"The first basic problem that must be solved before control synthesis can proceed is that of determining the dynamic characteristics of the engine. Accordingly, an analysis of the dynamic behavior of the turbojet engine with tail-pipe burning was made at the NACA Lewis laboratory and is presented herein" (p. 1).
Analysis of a spin and recovery from time histories of attitudes and velocities as determined for a dynamic model of a contemporary fighter airplane in the free-spinning tunnel
From Introduction: "In this paper are presented descriptions of the camera setups and associated equipment, the equations and methods used in determining the model attitudes and motions from the film, and time-history curves of the variables of the spin and recovery investigated. Discussions of the nature of the spin and recovery obtained and of factors ostensibly affecting these motions are included."
Analysis of a Strut With a Single Elastic Support in the Span, With Applications to the Design of Airplane Jury-Strut Systems
Report presenting an analysis of a wing brace with a small auxiliary strut, which is attached to the wing spar at the upper end. The design is quite effective but has some difficult analysis problems. The report is broken into two parts; one is a theoretical investigation and one is an experimental investigation.
An analysis of acceleration, airspeed, and gust-velocity data from a four-engine transport airplane in operations on an eastern United States route
Report presenting time-history data obtained by the NACA VGH recorder from a model of a four-engine civil transport airplane during operations on an eastern United States route in order to determine magnitude and frequency of occurrence of gusts, gust accelerations, and associated airspeeds. The results are compared with results from two similar operations. The gust-load history for the operation was more severe than that for the other two operations.
An analysis of acceleration, airspeed, and gust-velocity data from one type of four-engine transport airplane operated over two domestic routes
From Introduction: "As part of a continuing study of the gust and load histories for transport airplanes (see, for example, refs. 1 and 2), samples of VGH records have been obtained from two four-engine commercial transport airplanes. The data samples represent 839 and 1,080 flight hours of operation on two transcontinental routes and cover operations up to an altitude of 25,000 feet."
An analysis of accelerations, airspeeds, and gust velocities from three commercial operations of one type of medium-altitude transport airplane
From Introduction: "Past analyses of data from the NACA V-G and the NACA VGH recorders (see, for example, refs. 1 and 2) have yielded information on the magnitude and frequency of occurrence of gust and maneuver accelerations, and the associated airspeeds and altitudes for several types of airplanes flown by different operators on various routes."
Analysis of accelerations, gust velocities, and airspeeds from operations of a twin-engine transport airplane on a transcontinental route from 1950 to 1952
Report presenting time-history data obtained from one type of twin-engine transport airplane during two years of operations on a transcontinental route, which is analyzed in order to determine the magnitude and frequency of occurrence of gust accelerations, gust velocities, and associated airspeeds and altitudes. The gusts were found to be in good agreement with those previously reported for another type of twin-engine transport airplane.
Analysis of accuracy of gas-filled bellows for sensing gas density
From Summary: "An analysis is presented of the characteristics of gas-filled bellows for sensing gas density to delineate the factors that affect the accuracy of this type of bellows."
An analysis of airspeed, altitude, and acceleration data obtained from a twin-engine transport airplane operated over a feeder-line route in the Rocky Mountains
"Time-history data of airspeed, altitude, and acceleration obtained with the NACA VGH recorder from a twin-engine airplane operated by a regional feeder airline in the Rocky Mountains are evaluated to determine the magnitude and frequency of occurrence of gusts and gust accelerations and the operating airspeeds and altitudes. The results obtained are compared with the results previously obtained from a representative short-haul and long-haul operation" (p. 1).
Analysis of an induction blowdown supersonic tunnel
From Introduction: "In the present paper, general ejector equations (see reference 4 or 5) and certain assumptions with regard to flow conditions and pressure losses have been utilized to calculate the running times of induction blowdown supersonic tunnels operating in the mentioned Mach number range."
An analysis of an x-ray absorption method for measurement of high gas temperatures
From Introduction: "A theoretical analysis of the factors involved in the measurement of the temperature of gaseous combustion products by the X-ray absorption method is presented herein."
Analysis of Available Data on the Effects of Tabs on Control-Surface Hinge Moments
From Introduction: "A collection balanced-aileron test data is given in reference 1. Reference 2 presents a collection of data applicable to the design of tail surfaces. The results of analyses of data for control surfaces with internal balances, plain-overhang and Frise balances, beveled trailing edges, and unshielded horn balances have already been published in references 3 to 6."
An analysis of base pressure at supersonic velocities and comparison with experiment
From Introduction: "The primary purpose of the investigation described in the present report is to formulate a method which is of value for quantitative calculations of base pressure on airfoils and bodies without boat-tailing. Part I consists of a detailed study of the base pressure in two-dimensional and axially-symmetric inviscid flow. In part II a semi-empirical theory is formulated since the results of part I indicate that an inviscid-flow theory cannot possibly be satisfactory for quantitative calculations of a viscous flow."
Analysis of behavior of simply supported flat plates compressed beyond the buckling load into the plastic range
From Summary and Introduction: "An analysis is presented of the postbuckling behavior of a simply supported square flat plate with straight edges compressed beyond the buckling load into the plastic range. The method of analysis involves the application of a variational principle of the deformation theory of plasticity in conjunction with computations carried out on a high-speed calculating machine. The results of the analysis are presented in the form of curves showing the variation of deformations, stress distribution, average compressive stress, and effective width with the applied unit shortening."
An analysis of buzzing in supersonic ram jets by a modified one-dimensional nonstationary wave theory
From Introduction: "The buzz or pulsation of axially symmetric supersonic inlets having central bodies has been the subject of investigations since Oswatitsch first observed the phenomenon in 1944 (ref.1). This buzzing is essentially an oscillation of the normal shock along the spike of certain diffusers operating at mass flows below design, and this buzz decreases the performance of the propulsion units appreciably (ref.2). This paper continues the analysis of the buzzing cycle by means of a modified one-dimensional approach."
Analysis of Circular Shell-Supported Frames
From Summary: "This paper deals with the single problem if circular shell-supported frames subjected to concentrated loadings. A mathematical attack is developed and presented in the form of nondimensional-coefficient curves."
Analysis of Cylinder-Pressure-Indicator Diagrams Showing Effects of Mixture Strength and Spark Timing
"An investigation was made to determine the effect of mixture strength and of normal as well as optimum spark timing on the combustion, on the cylinder temperature, and on the performance characteristics of an engine. A single-cylinder test unit utilizing an air-cooled cylinder and a carburetor and operating with gasoline having an octane rating of 92 was used. The investigation covered a range of fuel-air ratios from 0.053 to 0.118. Indicator diagrams and engine-performance data were taken for each change in engine conditions" (p. 1).
Analysis of Deep Rectangular Shear Web Above Buckling Load
From Introduction: "An analysis of a square web above the buckling load was presented in reference 1. The analysis of reference 1 therefore was repeated for a shear web with depth/width = 2.5. Comparison of the results with those for the square web then would indicate the effect in the depth-width ratio."
Analysis of Dr. Schaffran's Propeller Model Tests
Note presenting an analysis of the propeller model tests of Dr. Schaffran. Only the thrust is examined. The results indicate that the thrust produced by three-blade and four-blade propellers follows the same laws as with two-blade propellers, and that all conclusions reached from Dr. Durand's tests can be upheld.
Analysis of Ear Formation in Deep-Drawn Cups
From Introduction: "The purpose of this paper is to show that the number and location of ears can be computed on the basis of single-crystal behavior and a knowledge of the orientation of the polycrystalline aggregate. Although the proposed method is a general one, only face-centered cubic metals are considered in this paper."
Analysis of effect of variations in primary variables on time constant and turbine-inlet-temperature overshoot of turbojet engine
From Introduction: "The design of turbojet-engine control systems is intimately related to the dynamic characteristics of the engine and has advanced to the stage where theoretically correct control constants can be determined for fixed dynamic properties (references 1 and 2). The use of the thermodynamic equations presupposes that the engine processes are quansi-static. Such an assumption is shown to be valid for a turbojet engine in references 3 and 4.
Analysis of elastic thermal stresses in thin plate with spanwise and chordwise variations of temperature and thickness
From Introduction: "The object of the present paper is to present an approximate method for calculating accurately the thermal stresses in a thin plate with both chordwise and spanwise variations in temperature and chordwise but restricted spanwise variations in thickness."
Analysis of errors introduced by several methods of weighting nonuniform duct flows
From Introduction: "This report presents the results of an analytical study made to determine the accuracy with which several commonly used averaging or weighting methods reproduce the real flow properties."
An analysis of estimated and experimental transonic downwash characteristics as affected by plan form and thickness for wing and wing-fuselage configurations
From Introduction: "The purpose of the present paper is to present summary of the information gleaned from various transonic-bump investigations of wing and wing-fuselage configurations at two representative tail heights and to compare these results with theoretical estimations made in subsonic and supersonic Mach number range."
Analysis of factors influencing the stability characteristics of symmetrical twin-intake Air-induction systems
From Introduction: "Experimental investigations of air-induction systems in which the air flows of two intakes join in a common duct have inducted that many of these systems are subject to air-flow instability at low inlet-velocity ratios. Therefore, an analysis has been made to determine a proper basis for an explanation and to provide a more quantitative explanation of the flow instability and the flow reversal. This report presents the results of this analysis."
Analysis of Flight-Performance Measurements on a Twisted, Plywood-Covered Helicopter Rotor in Various Flight Conditions
From Introduction: "In references 1, 2, and 3, flight measurements of the performance of a conventional, single-rotor helicopter equipped with its production fabric-covered main rotor blades are presented."
Analysis of flow in a subsonic mixed-flow impeller
From Introduction: "A brief description of the method of analysis is presented herein considering the mean stream surface approach advanced in references 2 and 3, and both the incompressible and compressible solutions are given in detail."
An analysis of flow in rotating passage of large radial-inlet centrifugal compressor at tip speed of 700 feet per second
Report presenting an analysis of the flow in the rotating passages of a 48-inch diameter radial-inlet centrifugal impeller at a tip speed of 700 feet per second in order to provide more information on the flow conditions within the impeller. Results regarding the impeller and diffuser performance, design flow characteristics, and off-design flow characteristics are provided.
Analysis of Fully Developed Turbulent Heat Transfer and Flow in an Annulus With Various Eccentricities
From Introduction: "Most of the existing analyses for turbulent flow and heat transfer in passages have been confined to circular tubes or parallel plates (refs. 1 to 5). In reference 6, temperature distributions for rectangular and triangular ducts were calculated by using experimental velocity distributions and average heat-transfer coefficients. Some work on the calculation of the velocity and shear-stress distributions in corners is reported in reference 7."
Analysis of Ground Effect on the Lifting Airscrew
"A study is presented of ground effect as applied to the lifting airscrew of the type used in modern gyroplanes and helicopters. The mathematical analysis of the problem has been verified by tests made of three rotor models in the presence of a large circular "ground plane." The results of the study are presented in the form of convenient charts" (p. 1).
Analysis of harmonic forces produced at hub by imbalances in helicopter rotor blades
From Introduction: "First, an analysis of loads transmitted to the hub by balanced blades will be given. In the second section, the additional loads transmitted to the hub in a direction normal to the plane of rotation of the blades by imbalances in a rotor are derived. In the entire analysis, the results are given in terms of the forces transmitted to the hub by a single rotating helicopter blade in flight, and these are regarded as known or given."
Analysis of heat addition in a convergent-divergent nozzle
From Introduction: "The purpose of this report is to treat analytically heat addition heat addition to a divergent stream with initially sonic flow and to employ the results thus obtained in evaluating the effect of delayed combustion on convergent-divergent nozzle performance."
Analysis of horizontal-tail loads in pitching maneuvers on a flexible swept-wing jet bomber
From Introduction: "The analysis of flight data in the present report is, to a large extent, based on analyses and information contained in references 1 and 2 for wing deflections, reference 3 for horizontal-tail parameters, reference 4 for airplane lift-curve slopes and angles of zero lift, and reference 5 for wing centers of pressure."
Analysis of Laminar Forced-Convection Heat Transfer in Entrance Region of Flat Rectangular Ducts
From Introduction: "Beyond the position where the boundary layer treatment can no longer be used, curves have been faired to connect the Nusselt number results of the present analysis with those of reference 3, in which a parabolic velocity profile is assumed throughout the entire duct length. So that a comparison could be made with the results of reference 3, the boundary layer analysis was used to study the development of the temperature profile associated with a parabolic velocity profile throughout."
An Analysis of Laminar Free-Convection Flow and Heat Transfer About a Flat Plate Parallel to the Direction of the Generating Body Force
From Introduction: "The problem of free-convection flow as produced by a body force about a flat plate in the direction of the body force was studied at the NACA Lewis laboratory and is treated in a formal and more general manner herein. The method used is somewhat similar to that used in reference 4 wherein consideration was given to the free-convection flow at high Grashof numbers in a horizontal cylinder which had a variable surface-temperature distribution. In addition, the numerical solutions of references 2 and 3 are herein extended to cover a more complete range of variables."
Analysis of laminar incompressible flow on semiporous channels
From Introduction: "Experimental results for flow in a rectangular channel with injection through a porous wall are given in reference 1. As part of the study to guide future experiments, laminar flow in a semiporous channel is investigated herein. In the present investigation, a third-order perturbation solution for laminar incompressible flow in a semiporous channel is presented."
Analysis of Landing-Gear Behavior
Note presenting an analytical study of the behavior of the conventional type of oleo-pneumatic landing gear during the process of landing impact. The basic analysis is presented in a general form and treats the motions of the landing gear prior to and subsequent to the beginning of shock-strut deflection.
Analysis of means of improving the uncontrolled lateral motions of personal airplanes
From Summary: "The purpose of this investigation was to determine whether such airplanes could be made to fly uncontrolled for an indefinite period of time without getting into dangerous attitudes and for a reasonable period of time (one to three minutes) without deviating excessively from their original course. The results of this analysis indicated that the uncontrolled motions of a personal airplane could be made safe as regards spiral tendencies and could be greatly improved as regards maintenance of course without resort to an autopilot."
Analysis of Multicell Delta Wings on Cal-Tech Analog Computer
"The main purpose of this paper is to present the results of measurements made on the Cal-Tech computer. The diagrams present only a small portion of the data which were obtained from the computer and which are given in complete form in the tables" (p. 1-2).
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