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 Decade: 1940-1949
 Collection: National Advisory Committee for Aeronautics Collection
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/
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/
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/
An investigation of aircraft heaters IX : measured and predicted performance of two exhaust gas-air heat exchangers and an apparatus for evaluating exhaust gas-air heat exchangers
No Description digital.library.unt.edu/ark:/67531/metadc279620/
The Lagrangian Multiplier Method of Finding Upper and Lower Limits to Critical Stresses of Clamped Plates
The theory of Lagrangian multipliers is applied to the problem of finding both upper and lower limits to the true compressive buckling stress of a clamped rectangular plate. The upper and lower limits thus bracket the truss, which cannot be exactly found by the differential-equation approach. The procedure for obtaining the upper limit, which is believed to be new, presents certain advantages over the classical Raleigh-Rite method of finding upper limits. The theory of the lower-limit procedure has been given by Trefftz but, in the present application, the method differs from that of Trefftz in a way that makes it inherently more quickly convergent. It is expected that in other buckling problems and in some vibration problems problems the Lagrangian multiplier method finding upper and lower limits may be advantageously applied to the calculation of buckling stresses and natural frequencies. digital.library.unt.edu/ark:/67531/metadc279603/
A Concise Theoretical Method for Profile-Drag Calculation; Advance Report
In this report a method is presented for the calculation of the profile drag of airfoil sections. The method requlres only a knowledge of the theoretical velocity distribution and can be applied readily once this dlstribution is ascertained. Comparison of calculated and experimental drag characteristics for several airfoils shows a satisfactory agreement. Sample calculatlons are included. digital.library.unt.edu/ark:/67531/metadc279600/
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/
Analysis of heat and compressibility effects in internal flow systems and high-speed tests of a ram-jet system
No Description digital.library.unt.edu/ark:/67531/metadc279610/
Ditching tests with 1/10-size model of the Army A-20A airplane I : calm-water tests in NACA tank no.2
No Description digital.library.unt.edu/ark:/67531/metadc279645/
The use of geared spring tabs for elevator control
No Description digital.library.unt.edu/ark:/67531/metadc279612/
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/
Flight measurements of the effect of various amounts of aileron droop on the low-speed lateral-control characteristics of an observation airplane
No Description digital.library.unt.edu/ark:/67531/metadc279604/
Performance of an exhaust-gas "blowdown" turbine on a nine-cylinder radial engine
No Description digital.library.unt.edu/ark:/67531/metadc279622/
Determination of general relations for the behavior of turbulent boundary layers
No Description digital.library.unt.edu/ark:/67531/metadc279609/
The development and application of high-critical-speed nose inlets
No Description digital.library.unt.edu/ark:/67531/metadc279653/
Thermodynamic design of double-panel, air-heated windshields for ice prevention
No Description digital.library.unt.edu/ark:/67531/metadc279628/
An experimental investigation of rectangular exhaust-gas ejectors applicable for engine cooling
No Description digital.library.unt.edu/ark:/67531/metadc279654/
Flight studies of the horizontal-tail loads experienced by a fighter airplane in abrupt maneuvers
No Description digital.library.unt.edu/ark:/67531/metadc279611/
NACA Mach number indicator for use in high-speed tunnels
No Description digital.library.unt.edu/ark:/67531/metadc279639/
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/
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/
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/
Wind-tunnel investigation of the effects of spoilers on the characteristics of a low-drag airfoil equipped with a 0.25-chord slotted flap
No Description digital.library.unt.edu/ark:/67531/metadc279657/
On a new method for calculating the potential flow past a body of revolution
No Description digital.library.unt.edu/ark:/67531/metadc279642/
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/
Design of nozzles for the individual cylinder exhaust jet propulsion system
No Description digital.library.unt.edu/ark:/67531/metadc279672/
Profile-drag coefficients of conventional and low-drag airfoils as obtained in flight
No Description digital.library.unt.edu/ark:/67531/metadc279640/
A general representation for axial-flow fans and turbines
No Description digital.library.unt.edu/ark:/67531/metadc279615/
Air-consumption parameters for automatic mixture control of aircraft engines
No Description digital.library.unt.edu/ark:/67531/metadc279682/
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/
Flight tests of several exhaust-gas-to-air heat exchangers in the B-17F airplane
No Description digital.library.unt.edu/ark:/67531/metadc279674/
An investigation of aircraft heaters XVIII : a design manual for exhaust gas and air heat exchangers
No Description digital.library.unt.edu/ark:/67531/metadc279599/
Tests of a thermal ice-prevention system for a wing leading-edge landing-light installation
No Description digital.library.unt.edu/ark:/67531/metadc279556/
Supplement to Comparison of automatic control systems
This analysis deals with the indirect regulator, wherefrom the behavior of the direct regulator is deduced as a limiting case. The prime mover is looked upon as "independent of the load": a change in the adjusting power (to be applied) for the control link (as, for example, in relation to the adjusting path (eta) with pressure valves or the rudder of vessels) does not modify the actions of the prime mover. Mass forces and friction are discounted; "clearance" also is discounted in the transmission links of the regulator. digital.library.unt.edu/ark:/67531/metadc279595/
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/
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/
A laboratory investigation of the icing characteristics of the Bendix-Stromberg carburetor model PD-12F5 with the Pratt and Whitney R-1830-C4 intermediate rear engine section
No Description digital.library.unt.edu/ark:/67531/metadc279575/
Application of spring tabs to elevator controls
No Description digital.library.unt.edu/ark:/67531/metadc279509/
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/
On the plane potential flow past a symmetrical lattice of arbitrary airfoils
No Description digital.library.unt.edu/ark:/67531/metadc279550/
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/
The Measurement of Fuel-Air Ratio by Analysis for the Oxidized Exhaust Gas
An investigation was made to determine a method of measuring fuel-air ratio that could be used for test purposes in flight and for checking conventional equipment in the laboratory. Two single-cylinder test engines equipped with typical commercial engine cylinders were used. The fuel-air ratio of the mixture delivered to the engines was determined by direct measurement of the quantity of air and of fuel supplied and also by analysis of the oxidized exhaust gas and of the normal exhaust gas. Five fuels were used: gasoline that complied with Army-Navy fuel Specification No. AN-VV-F-781 and four mixtures of this gasoline with toluene, benzene, and xylene. The method of determining the fuel-air ratio described in this report involves the measurement of the carbon-dioxide content of the oxidized exhaust gas and the use of graphs for the presented equation. This method is considered useful in aircraft, in the field, or in the laboratory for a range of fuel-air ratios from 0.047 to 0.124. digital.library.unt.edu/ark:/67531/metadc279515/
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 flow of a compressible fluid past a curved surface
No Description digital.library.unt.edu/ark:/67531/metadc279581/
Analysis of wind-tunnel stability and control tests in terms of flying qualities in full-scale airplanes
No Description digital.library.unt.edu/ark:/67531/metadc279513/
Ultraviolet spectrochemical analysis for aromatics in aircraft fuels
No Description digital.library.unt.edu/ark:/67531/metadc279548/
Analysis of circular shell-supported frames
No Description digital.library.unt.edu/ark:/67531/metadc279501/
Effects of some present-day airplane design trends on requirements for lateral stability
No Description digital.library.unt.edu/ark:/67531/metadc279598/
Visual studies of cylinder lubrication I : the lubrication of the piston skirt
No Description digital.library.unt.edu/ark:/67531/metadc279552/
Fluid de-icing tests on a Chandler-Evans 1900 CPB-3 carburetor mounted on a Pratt & Whitney R-1830-C4 intermediate rear engine section
No Description digital.library.unt.edu/ark:/67531/metadc279533/
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