You limited your search to:

  Partner: UNT Libraries Government Documents Department
 Decade: 1940-1949
 Year: 1940
 Collection: National Advisory Committee for Aeronautics Collection
Aerodynamic characteristics of horizontal tail surfaces

Aerodynamic characteristics of horizontal tail surfaces

Date: January 1, 1940
Creator: Silverstein, Abe & Katzoff, S
Description: Collected data are presented on the aerodynamic characteristics of 17 horizontal tail surfaces including several with balanced elevators and two with end plates. Curves are given for coefficients of normal force, drag, and elevator hinge moment. A limited analysis of the results has been made. The normal-force coefficients are in better agreement with the lifting-surface theory of Prandtl and Blenk for airfoils of low aspect ratio than with the usual lifting-line theory. Only partial agreement exists between the elevator hinge-moment coefficients and those predicted by Glauert's thin-airfoil theory.
Contributing Partner: UNT Libraries Government Documents Department
Aerodynamic heating and the deflection of drops by an obstacle in an air stream in relation to aircraft icing

Aerodynamic heating and the deflection of drops by an obstacle in an air stream in relation to aircraft icing

Date: October 1, 1940
Creator: Kantrowitz, Arthur
Description: Two topics of interest to persons attempting to apply the heat method of preventing ice formation on aircraft are considered. Surfaces moving through air at high speed are shown, both theoretically and experimentally, to be subject to important aerodynamic heating effects that will materially reduce the heat required to prevent ice. Numerical calculations of the path of water drops in an air stream around a circular cylinder are given. From these calculations, information is obtained on the percentage of the swept area cleared of drops.
Contributing Partner: UNT Libraries Government Documents Department
Aerodynamics of rotating-wing aircraft with blade-pitch control

Aerodynamics of rotating-wing aircraft with blade-pitch control

Date: February 1, 1940
Creator: Pfluger, A
Description: In the present report, with the aid of the usual computation methods, a rotor is investigated the pitch of whose blades is capable of being controlled in such a manner that it varies linearly with the flapping angle. To test the effect of this linkage on the aircraft performance, the theory is applied to an illustrative example.
Contributing Partner: UNT Libraries Government Documents Department
The aileron as an aid to recovery from the spin

The aileron as an aid to recovery from the spin

Date: September 1, 1940
Creator: Neihouse, A I
Description: As part of a general investigation by the NACA of factors that affect the spin, the use of the aileron as an aid to recovery from the spin was studied. Tests of 10 different models, covering a wide range of mass distribution, were made in the NACA free-spinning tunnel to determine the effects of a large downward deflection of the outboard aileron and of normal angular deflections of the ailerons upon recovery characteristics. The results indicate that the direction of aileron setting, with or against the spin, which will aid recovery from the spin depends upon the airplane weight distribution. For monoplanes and for biplanes with lower-wing ailerons, ailerons with the spin will be favorable when the weight is distributed chiefly along the fuselage (single-engine airplanes) and ailerons against the spin will be favorable when the weight is distributed chiefly along the wings (multi engine airplanes). Downward movement of the outboard aileron through a large angle will not always be effective in aiding recovery, the effectiveness of such a movement also being dependent upon the weight distribution of the airplane.
Contributing Partner: UNT Libraries Government Documents Department
Analysis of cylinder-pressure-indicator diagrams showing effects of mixture strength and spark timing

Analysis of cylinder-pressure-indicator diagrams showing effects of mixture strength and spark timing

Date: August 1, 1940
Creator: Gerrish, Harold C & Voss, Fred
Description: 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. Examination of the indicator shows that for fuel-air ratios less than and greater than 0.082 the rate and the amount of effective fuel burned decreased. For a fuel-air ratio of 0.118 the combustion efficiency was only 58 percent. Advancing the spark timing increased the rate of pressure rise. This effect was more pronounced with leaner mixtures.
Contributing Partner: UNT Libraries Government Documents Department
Analysis of wind-tunnel data on directional stability and control

Analysis of wind-tunnel data on directional stability and control

Date: September 1, 1940
Creator: Pass, H R
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Annual report of the National Advisory Committee for Aeronautics (25th).administrative report including Technical Report nos. 645 to 680

Annual report of the National Advisory Committee for Aeronautics (25th).administrative report including Technical Report nos. 645 to 680

Date: January 1, 1940
Creator: unknown
Description: Report includes the National Advisory Committee for Aeronautics letter of submittal to the President, summaries of the committee's activities and research accomplished, bibliographies, and financial report.
Contributing Partner: UNT Libraries Government Documents Department
The application of basic data on planing surfaces to the design of flying-boat hulls

The application of basic data on planing surfaces to the design of flying-boat hulls

Date: January 1940
Creator: Diehl, Walter S.
Description: Basic lift data on planing surfaces have been analyzed and the data applied to the design of flying-boat hulls. It is shown that a balance between air and water forces requires that the beam of the planing area bear a relation to the wing area that is determined by the lift coefficient of the wing and by the angle of dead rise in the planing surface. It is also shown that the fore-and-aft extent of the required planing area depends on the angle of dead rise. Failure to provide sufficient length of planing area appears to be the main reason for the poor water performance sometimes obtained when a large angle of dead rise is used.
Contributing Partner: UNT Libraries Government Documents Department
Application of the methods of gas dynamics to water flows with free surface I : flows with no energy dissipation

Application of the methods of gas dynamics to water flows with free surface I : flows with no energy dissipation

Date: March 1, 1940
Creator: Preiswerk, Ernst
Description: The application is treated in sufficient detail to facilitate as much as possible its application by the engineer who is less familiar with the subject. The present work was undertaken with two objects in view. In the first place, it is considered as a contribution to the water analogy of gas flows, and secondly, a large portion is devoted to the general theory of the two-dimensional supersonic flows.
Contributing Partner: UNT Libraries Government Documents Department
Application of the methods of gas dynamics to water flows with free surface II : flows with momentum discontinuities (hydraulic jumps)

Application of the methods of gas dynamics to water flows with free surface II : flows with momentum discontinuities (hydraulic jumps)

Date: March 1, 1940
Creator: Preiswerk, Ernst
Description: In this paper an introduction to shock polar diagrams is given which then leads into an examination of water depths in hydraulic jumps. Energy loss during these jumps is considered along with an extended look at elementary solutions of flow. An experimental test set-up is described and the results presented.
Contributing Partner: UNT Libraries Government Documents Department
An Approximate Method of Calculation of Relative Humidity Required to Prevent Frosting on Inside of Aircraft Pressure Cabin Windows, Special Report

An Approximate Method of Calculation of Relative Humidity Required to Prevent Frosting on Inside of Aircraft Pressure Cabin Windows, Special Report

Date: December 5, 1940
Creator: Jones, Alun R.
Description: This report has been prepare in response to a request for information from an aircraft company. A typical example was selected for the presentation of an approximate method of calculation of the relative humidity required to prevent frosting on the inside of a plastic window in a pressure type cabin on a high speed airplane. The results of the study are reviewed.
Contributing Partner: UNT Libraries Government Documents Department
Boundary-Layer Transition on the N.A.C.A. 0012 and 23012 Airfoils in the 8-Foot High-Speed Wind Tunnel

Boundary-Layer Transition on the N.A.C.A. 0012 and 23012 Airfoils in the 8-Foot High-Speed Wind Tunnel

Date: January 1, 1940
Creator: Becker, John V
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Boundary-Layer Transition on the N.A.C.A. 0012 and 23012 Airfoils in the 8-Foot High-Speed Wind Tunnel, Special Report

Boundary-Layer Transition on the N.A.C.A. 0012 and 23012 Airfoils in the 8-Foot High-Speed Wind Tunnel, Special Report

Date: January 1, 1940
Creator: Becker, John V.
Description: Determinations of boundary-layer transition on the NACA 0012 and 2301 airfoils were made in the 8-foot high-speed wind tunnel over a range of Reynolds Numbers from 1,600,000 to 16,800,000. The results are of particular significance as compared with flight tests and tests in wind tunnels of appreciable turbulence because of the extremely low turbulence in the high-speed tunnel. A comparison of the results obtained on NACA 0012 airfoils of 2-foot and 5-foot chord at the same Reynolds Number permitted an evaluation of the effect of compressibility on transition. The local skin friction along the surface of the NACA 0012 airfoil was measured at a Reynolds Number of 10,000,000. For all the lift coefficient at which tests were made, transition occurred in the region of estimated laminar separation at the low Reynolds Numbers and approach the point of minimum static pressure as a forward limit at the high Reynolds Numbers. The effect of compressibility on transition was slight. None of the usual parameters describing the local conditions in the boundary layer near the transition point served as an index for locating the transition point. As a consequence of the lower turbulence in the 8-foot high-speed tunnel, the transition points occurred consistently ...
Contributing Partner: UNT Libraries Government Documents Department
Buckling tests with a spar-rib grill

Buckling tests with a spar-rib grill

Date: September 1, 1940
Creator: Weinhold, Josef
Description: The present report deals with a comparison of mathematically and experimentally defined buckling loads of a spar-rib grill, on the assumption of constant spar section, and infinitely closely spaced ribs with rigidity symmetrical to the grill center. The loads are applied as equal bending moments at both spar ends, as compression in the line connecting the joints, and in the spar center line as the assumedly uniformly distributed spar weight.
Contributing Partner: UNT Libraries Government Documents Department
The calculated effect of various hydrodynamic and aerodynamic factors on the take-off of a large flying boat

The calculated effect of various hydrodynamic and aerodynamic factors on the take-off of a large flying boat

Date: January 1, 1940
Creator: Olson, R E & Allison, J M
Description: Report presents the results of an investigation made to determine the influence of various factors on the take-off performance of a hypothetical large flying boat by means of take-off calculations. The factors varied in the calculations were size of hull (load coefficient), wing setting, trim, deflection of flap, wing loading, aspect ratio, and parasite drag. The take-off times and distances were calculated to the stalling speeds and the performance above these speeds was separately studied to determine piloting technique for optimum take-off.
Contributing Partner: UNT Libraries Government Documents Department
The cause of welding cracks in aircraft steels

The cause of welding cracks in aircraft steels

Date: October 1, 1940
Creator: Muller, J
Description: The discussion in this article refers to gas welding of thin-walled parts of up to about 3 mm thickness. It was proven that by restricting the sulphur, carbon, and phosphorous content, and by electric-furnace production of the steel, it was possible in a short time to remove this defect. Weld hardness - i.e., martensite formation and hardness of the overheated zone - has no connection with the tendency to weld-crack development. Si, Cr, Mo, or V content has no appreciable effect, while increased manganese content tends to reduce the crack susceptibility.
Contributing Partner: UNT Libraries Government Documents Department
Chart for critical compressive stress of flat rectangular plates

Chart for critical compressive stress of flat rectangular plates

Date: August 1, 1940
Creator: Hill, H N
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Chordwise load distribution of a simple rectangular wing

Chordwise load distribution of a simple rectangular wing

Date: December 1, 1940
Creator: Wieghardt, Karl
Description: The chordwise distribution theory was taken over from the theory of the infinite wing. Since in this work a series expansion in b/t was used, the computation converges only for large aspect ratios. In this paper a useful approximate solution will be found also for wings with large chord - i.e., small aspect ratio.
Contributing Partner: UNT Libraries Government Documents Department
Comparison of Three Exit-Area Control Devices on an N.A.C.A. Cowling, Special Report

Comparison of Three Exit-Area Control Devices on an N.A.C.A. Cowling, Special Report

Date: May 1, 1940
Creator: McHugh, James G.
Description: Adjustable cowling flaps, an adjustable-length cowling skirt, and a bottom opening with adjustable flap were tested as means of controlling the rate of cooling-air flow through an air-cooled radial-engine cowling. The devices were tested in the NACA 20-foot tunnel on a model wing-nacelle-propeller combination, through an airspeed range of 20 to 80 miles per hour, and with the propeller blade angle set 23 degrees at 0.75 of the tip radius. The resistance of the engine to air flow through the cowling was simulated by a perforated plate. The results indicated that the adjustable cowling flap and the bottom opening with adjustable flap were about equally effective on the basis of pressure drop obtainable and that both were more effective means of increasing the pressure drop through the cowling than the adjustable-length skirt. At conditions of equal cooling-air flow, the net efficiency obtained with the adjustable cowling flaps and the adjustable-length cowling skirt was about 1% greater than the net efficiency obtained with the bottom opening with adjustable flap.
Contributing Partner: UNT Libraries Government Documents Department
Consideration of auxiliary jet propulsion for assisting take-off

Consideration of auxiliary jet propulsion for assisting take-off

Date: May 1, 1940
Creator: Turner, L Richard
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Constant-pressure blowers

Constant-pressure blowers

Date: January 1, 1940
Creator: Sorensen, E
Description: The conventional axial blowers operate on the high-pressure principle. One drawback of this type of blower is the relatively low pressure head, which one attempts to overcome with axial blowers producing very high pressure at a given circumferential speed. The Schicht constant-pressure blower affords pressure ratios considerably higher than those of axial blowers of conventional design with approximately the same efficiency.
Contributing Partner: UNT Libraries Government Documents Department
Corrections on the thermometer reading in an air stream

Corrections on the thermometer reading in an air stream

Date: October 1, 1940
Creator: Van Der Maas, H J & Wynia, S
Description: A method is described for checking a correction formula, based partly on theoretical considerations, for adiabatic compression and friction in flight tests and determining the value of the constant. It is necessary to apply a threefold correction to each thermometer reading. They are a correction for adiabatic compression, friction and for time lag.
Contributing Partner: UNT Libraries Government Documents Department
Correlation of cooling data from an air-cooled cylinder and several multicylinder engines

Correlation of cooling data from an air-cooled cylinder and several multicylinder engines

Date: January 1, 1940
Creator: Pinkel, Benjamin & Ellerbrock, Herman H , Jr
Description: The theory of engine-cylinder cooling developed in a previous report was further substantiated by data obtained on a cylinder from a Wright r-1820-g engine. Equations are presented for the average head and barrel temperatures of this cylinder as functions of the engine and the cooling conditions. These equations are utilized to calculate the variation in cylinder temperature with altitude for level flight and climb. A method is presented for correlating average head and barrel temperatures and temperatures at individual points on the head and the barrel obtained on the test stand and in flight. The method is applied to the correlation and the comparison of data obtained on a number of service engines. Data are presented showing the variation of cylinder temperature with time when the power and the cooling pressure drop are suddenly changed.
Contributing Partner: UNT Libraries Government Documents Department
Correlation of knocking characteristics of fuels in an engine having a hemispherical combustion chamber

Correlation of knocking characteristics of fuels in an engine having a hemispherical combustion chamber

Date: July 1, 1940
Creator: Rothrock, A M & Biermann, Arnold E
Description: Data are presented to show the effects of inlet-air pressure, inlet-air temperature, and compression ratio on the maximum permissible performance obtained with having a hemispherical-dome combustion chamber. The five aircraft-engine fuels used have octane numbers varying from 90 to 100 plus 2 ml of tetraethyl lead per gallon. The data were obtained on a 5 1/4-inch by 4 3/4-inch liquid-cooled engine operating at 2,500 r.p.m. The compression ratio was varied from 6.0 to 8.9. The inlet-air temperature was varied from 110 to 310 F. For each set of conditions, the inlet-air pressure was increased until audible knock occurred and then reduced 2 inches of mercury before data were recorded. The results for each fuel can be correlated by plotting the calculated end-gas density factor against the calculated end-gas temperature. Measurements of spark-plugs, cutting off the switch to one spark plug lowered the electrode temperature of that plug from a value of 1,365 F to a value of 957 F. The results indicate that the surface temperatures of combustion-chamber areas which become new sources of ignition markedly increase after ignition.
Contributing Partner: UNT Libraries Government Documents Department
FIRST PREV 1 2 3 4 5 NEXT LAST