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 Decade: 1940-1949
 Collection: National Advisory Committee for Aeronautics Collection
Some Recent Contributions to the Study of Transition and Turbulent Boundary Layers
No Description digital.library.unt.edu/ark:/67531/metadc172454/
Considerations of the Total Drag of Supersonic Airfoil Sections
The results of calculations of the viscous and pressure drags of some two-dimensional supersonic airfoils at zero lift are presented. The results indicate that inclusion of viscous drag alters many previous results regarding the desirability of certain airfoil shapes for securing low drags at supersonic speeds. At certain Reynolds and Mach numbers, for instance, a circular-arc airfoil may theoretically have less drag than the previously advocated symmetrical wedge-shape profile; although under different conditions, the circular-arc airfoil may have a higher drag. digital.library.unt.edu/ark:/67531/metadc172466/
Tables and Charts of Flow Parameters Across Oblique Shocks
Shock-wave equations have been evaluated for a range of Mach number in front of the shock from 1.05 to 4.0. Mach number behind the shock, pressure ratio, derivation of flow, and angle of shock are presented on charts. Values are also included for density ratio and change in entropy. digital.library.unt.edu/ark:/67531/metadc172508/
Two-Dimensional Irrotational Transonic Flows of a Compressible Fluid
The methods of NACA TN No. 995 have been slightly modified and extended in include flows with circulation by considering the alteration of the singularities of the incompressible solution due to the presence of the hypergeometric functions in the analytic continuation of the solution. It was found that for finite Mach numbers the only case in which the nature of the singularity can remain unchanged is for a ratio of specific heats equal to -1. From a study of two particular flows it seems that the effect of geometry cannot be neglected, and the conventional "pressure-correction" formulas are not valid, even in the subsonic region if the body is thick, especially if there is a supersonic region in the flow. digital.library.unt.edu/ark:/67531/metadc172480/
Charts for the Computation of Equilibrium Composition of Chemical Reactions in the Carbon-Hydrogen-Nitrogen System at Temperatures from 2000 to 5000 Degrees K
Charts are provided for the estimation and progressive adjustment of two independent variables on which the calculations are based. Additional charts are provided for the graphical calculation of the composition. digital.library.unt.edu/ark:/67531/metadc100821/
The effect of increased cooling surface on performance of aircraft-engine cylinders as shown by tests of the NACA cylinder
No Description digital.library.unt.edu/ark:/67531/metadc279569/
Calculations of economy of 18-cylinder radial aircraft engine with exhaust-gas turbine geared to the crankshaft at cruising speed
No Description digital.library.unt.edu/ark:/67531/metadc279432/
Correlation of exhaust-valve temperatures with engine operating conditions and valve design
No Description digital.library.unt.edu/ark:/67531/metadc279466/
The effect of exhaust-stack shape on the design and performance of the individual cylinder exhaust-gas jet-propulsion system
No Description digital.library.unt.edu/ark:/67531/metadc279425/
Design of nozzles for the individual cylinder exhaust jet propulsion system
No Description digital.library.unt.edu/ark:/67531/metadc279672/
Wind-tunnel tests of the 1/8-scale powered model of the Curtiss XBTC-2 airplane I : preliminary investigation of longitudinal stability
No Description digital.library.unt.edu/ark:/67531/metadc279558/
Compressibility and heating effects on pressure loss and cooling of a baffled cylinder barrel
No Description digital.library.unt.edu/ark:/67531/metadc279452/
The development and application of high-critical-speed nose inlets
No Description digital.library.unt.edu/ark:/67531/metadc279653/
Lifting-surface-theory aspect-ratio corrections to the lift and hinge-moment parameters for full-span elevators on horizontal tail surfaces
A limited number of lifting-surface-theory solutions for wings with chordwise loadings resulting from angle of attack, parabolic-ac camber, and flap deflection are now available. These solutions were studied with the purpose of determining methods of extrapolating the results in such a way that they could be used to determine lifting-surface-theory values of the aspect-ratio corrections to the lift and hinge-moment parameters for both angle-of-attack and flap-deflection-type loading that could be used to predict the characteristics of horizontal tail surfaces from section data with sufficient accuracy for engineering purposes. Such a method was devised for horizontal tail surfaces with full-span elevators. In spite of the fact that the theory involved is rather complex, the method is simple to apply and may be applied without any knowledge of lifting-surface theory. A comparison of experimental finite-span and section value and of the estimated values of the lift and hinge-moment parameters for three horizontal tail surfaces was made to provide an experimental verification of the method suggested. (author). digital.library.unt.edu/ark:/67531/metadc279678/
A theoretical investigation of the lateral oscillations of an airplane with free rudder with special reference to the effect of friction
No Description digital.library.unt.edu/ark:/67531/metadc279582/
Comparison of Vee-Type and Conventional Tail Surfaces in Combination with Fuselage and Wing in the Variable-Density Tunnel
The pitching and the yawing moments of a vee-type and a conventional type of tail surface were measured. The tests were made in the presence of a fuselage and a wing-fuselage combination in such a way as to determine the moments contributed by the tail surfaces. The results showed that the vee-type tail tested, with a dihedral angle of 35.3 deg, was about 71 percent as effective in pitch as the conventional tail and had a yawing-moment to pitching-moment ratio of 0.3. The conventional tail, the panels of which were all congruent to those of the vee-type tail, had a yawing-moment to pitching-moment ratio of 0.48. These ratios are in fair agreement with values calculated by methods shown in this and previous reports. The values of the measured moments were reduced from 15 to 25 percent of the calculated value by fuselage interference. digital.library.unt.edu/ark:/67531/metadc279435/
Experiments on drag of revolving disks, cylinders and streamline rods at high speeds
No Description digital.library.unt.edu/ark:/67531/metadc279467/
The effect of altitude on cooling
No Description digital.library.unt.edu/ark:/67531/metadc279422/
Flight Tests of Modifications to Improve the Aileron Control Characteristics of a North American XP-51 Airplane (AC No. 41-38)
Investigations were undertaken to improve the ailerons of a P-51 fighter so as to obtain greater effectiveness without increasing the stick forces. Modifications consisted of increasing the deflection range of the aileron to 70 percent and changing the original concave section to a thick section with beveled trailing edge. Results of the modified ailerons showed an increase in effectiveness over the original aileron of 70 percent at low speed and 55 percent at high speeds. digital.library.unt.edu/ark:/67531/metadc279546/
Application of spring tabs to elevator controls
No Description digital.library.unt.edu/ark:/67531/metadc279509/
Flight studies of the horizontal-tail loads experienced by a fighter airplane in abrupt maneuvers
No Description digital.library.unt.edu/ark:/67531/metadc279611/
On the flow of a compressible fluid by the hodography method I : unification and extension of present-day results
No Description digital.library.unt.edu/ark:/67531/metadc279666/
On the flow of a compressible fluid by the hodography method II : fundamental set of particular flow solutions of the Chaplygin differential equation
No Description digital.library.unt.edu/ark:/67531/metadc279417/
Critical combinations of shear and transverse direct stress for an infinitely long flat plate with edges elastically restrained against rotation
No Description digital.library.unt.edu/ark:/67531/metadc279557/
Effects of some present-day airplane design trends on requirements for lateral stability
No Description digital.library.unt.edu/ark:/67531/metadc279598/
Methods of analyzing wind-tunnel data for dynamic flight conditions
The effects of power on the stability and the control characteristics of an airplane are discussed and methods of analysis are given for evaluating certain dynamic characteristics of the airplane that are not directly discernible from wind-tunnel tests alone. Data are presented to show how the characteristics of a model tested in a wind tunnel are affected by power. The response of an airplane to a rolling and a yawing disturbance is discussed, particularly in regard to changes in wing dihedral and fin area. Solutions of the lateral equations of motion are given in a form suitable for direct computations. An approximate formula is developed that permits the rapid estimation of the accelerations produced during pull-up maneuvers involving abrupt elevator deflections. digital.library.unt.edu/ark:/67531/metadc279446/
NACA Mach number indicator for use in high-speed tunnels
No Description digital.library.unt.edu/ark:/67531/metadc279639/
NACA Investigation of a Jet-Propulsion System Applicable to Flight
Following a brief history of the NACA investigation of jet-propulsion, a discussion is given of the general investigation and analyses leading to the construction of the jet-propulsion ground-test mock-up. The results of burning experiments and of test measurements designed to allow quantitative flight-performance predictions of the system are presented and correlated with calculations. These calculations are then used to determine the performance of the system on the ground and in the air at various speeds and altitudes under various burning conditions. The application of the system to an experimental airplane is described and some performance predictions for this airplane are made. It was found that the main fire could be restricted to an intense, small, and short annular blue flame burning steadily and under control in the intended combustion space. With these readily obtainable combustion conditions, the combustion chamber the nozzle walls and the surrounding structure could be maintained at normal temperatures. The system investigated was found to be capable of burning one-half the intake air up the fuel rates of 3 pounds per second. Calculations were shown to agree well with experiment. It was concluded that the basic features of the jet-propulsion system investigation in the ground-test mock-up were sufficiently developed to be considered applicable to flight installation. Calculations indicated that an airplane utilizing this jet-propulsion system would have unusual capabilities in the high-speed range above the speeds of conventional aircraft and would, in addition, have moderately long cruising ranges if only the engine were used. digital.library.unt.edu/ark:/67531/metadc279418/
The propeller and cooling-air-flow characteristics of a twin-engine airplane model equipped with NACA D(sub S)-type cowlings and with propellers of NACA 16-series airfoil sections
No Description digital.library.unt.edu/ark:/67531/metadc279496/
Profile-drag coefficients of conventional and low-drag airfoils as obtained in flight
No Description digital.library.unt.edu/ark:/67531/metadc279640/
Review of flight tests of NACA C and D cowlings on the XP-42 airplane
No Description digital.library.unt.edu/ark:/67531/metadc279477/
The flow of a compressible fluid past a circular arc profile
No Description digital.library.unt.edu/ark:/67531/metadc279480/
The flow of a compressible fluid past a curved surface
No Description digital.library.unt.edu/ark:/67531/metadc279581/
On the plane potential flow past a symmetrical lattice of arbitrary airfoils
No Description digital.library.unt.edu/ark:/67531/metadc279550/
A method for studying the hunting oscillations of and airplane with a simple type of automatic control
No Description digital.library.unt.edu/ark:/67531/metadc279458/
Spin tests of two models of a low-wing monoplane to investigate scale effect in the model test range
No Description digital.library.unt.edu/ark:/67531/metadc279675/
On a new method for calculating the potential flow past a body of revolution
No Description digital.library.unt.edu/ark:/67531/metadc279642/
Single-cylinder oil-control tests of porous chrome plated cylinder barrels for radial air-cooled engines
No Description digital.library.unt.edu/ark:/67531/metadc279560/
The problem of longitudinal stability and control at high speeds
No Description digital.library.unt.edu/ark:/67531/metadc279426/
Wind-tunnel procedure for determination of critical stability and control characteristics of airplanes
No Description digital.library.unt.edu/ark:/67531/metadc279429/
A method for calculating heat transfer in the laminar flow region of bodies
No Description digital.library.unt.edu/ark:/67531/metadc279431/
Effect of the performance of a turbosupercharged engine of an exhaust-gas-to-air heat exchanger for thermal ice prevention
No Description digital.library.unt.edu/ark:/67531/metadc279594/
The effect of compressibility on two-dimensional tunnel-wall interference for a symmetrical airfoil
Summary: The effective change in the velocity of flow past a wing section, caused by the presence of wind-tunnel walls, is known for potential flow. This theory is extended by investigation of the two-dimensional compressible flow past a thin Rankine Oval. It is shown that for a symmetrical section at zero angle of attack the velocity increment due to the tunnel walls in the incompressible case must be multiplied by the factor 1/1-M^2 to take account of compressibility effects. The Mach number, M, corresponds to conditions in the wind-tunnel test section with the model removed (p. 1.). digital.library.unt.edu/ark:/67531/metadc279468/
Performance of an exhaust-gas "blowdown" turbine on a nine-cylinder radial engine
No Description digital.library.unt.edu/ark:/67531/metadc279622/
An investigation of a thermal ice-prevention system for a C-46 cargo airplane III : description of thermal ice-prevention equipment for wings, empennage, and windshield
No Description digital.library.unt.edu/ark:/67531/metadc279602/
An investigation of a thermal ice-prevention system for a C-46 cargo airplane II : the design, construction, and preliminary tests of the exhaust-air heat exchanger
No Description digital.library.unt.edu/ark:/67531/metadc279494/
An investigation of a thermal ice-prevention system for a C-46 cargo airplane IV : results of flight tests in dry-air and natural-icing conditions
No Description digital.library.unt.edu/ark:/67531/metadc279606/
An investigation of a thermal ice-prevention system for a C-46 cargo airplane V : effect of thermal system on airplane cruise performance
No Description digital.library.unt.edu/ark:/67531/metadc279663/
An investigation of a thermal ice-prevention system for a C-46 cargo airplane VI : dry-air performance of thermal system at several twin- and single-engine operating conditions at various altitudes
No Description digital.library.unt.edu/ark:/67531/metadc279617/
Flight tests of thermal ice-prevention equipment in the XB-24F airplane
No Description digital.library.unt.edu/ark:/67531/metadc279541/
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