National Advisory Committee for Aeronautics (NACA) - 41 Matching Results

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Activation of hydrocarbons and the octane number

Description: This report presents an examination of the history of research on engine knocking and the various types of fuels used in the investigations of this phenomenon. According to this report, the spontaneous ignition of hydrocarbons doped with oxygen follows the logarithmic law within a certain temperature range, but not above 920 degrees K. Having extended the scope of investigations to prove hydrocarbons, the curves of the mixtures burned by air should then be established by progressive replacement… more
Date: October 1939
Creator: Peschard, Marcel
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Airfoil Theory at Supersonic Speed

Description: From Summary: "A theory is developed for the airfoil of finite span at supersonic speed analogous to the Prandtl airfoil theory of 1918-1919 for incompressible flow. In addition to the profile and induced drags, account must be taken at supersonic flow of still another drag, namely, the wave drag, which is independent of the wing aspect ratio. Both wave and induced drags are proportional to the square of the lift and depend on the Mach number, that is, the ratio of flight to sound speed. In gen… more
Date: June 1939
Creator: Schlichting, H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Breda Wind Tunnel

Description: A description of the design and construction of the Breda wind tunnel. The tunnel is equipped with a two-meter throat diameter and a 310 kph velocity potential.
Date: December 1939
Creator: Pittoni, Mario
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Calculation of the Induced Efficiency of Heavily Loaded Propellers Having Infinite Number of Blades

Description: Report presenting an approximate method of computing the induced efficiency of heavily loaded propellers in suitable form for extension to finite number of blades and a comparison of results obtained using the method with the data of the Betz-Helmbold theory for heavily loaded propellers.
Date: January 1939
Creator: Lösch, F.; Kramer, K. N.; Bock, G. & Nikodemus, R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Comparison of Theory With Experiment in the Phenomenon of Wing Flutter

Description: Direct measurements were undertaken at the Aeronautics Laboratory in Turin of the aerodynamic actions on an oscillating wing. The tests conducted had as their essential object the examination of the operation of apparatus designed for this measurement. The values experimentally obtained for the aerodynamic coefficients are in good agreement with the theory of oscillatory motion of the wing of finite span and show clear deviation from the values obtained by theory of plane motion.
Date: February 1939
Creator: Cicala, P.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Contribution to the Aerodynamics of Rotating-Wing Aircraft

Description: "The chief defect of the investigations up to now was the assumption of a more or less arbitrary "mean" drag coefficient for a section of the blade. This defect is remedied through replacement of the constant coefficient by a function of higher order which corresponds to the polar curve of the employed profile. In that way it is possible to extend the theory to include the entire range from "autogyro" without power input to the driven "helicopter" with forward-tilted rotor axis. The treatment i… more
Date: December 1939
Creator: Sissingh, G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Contribution to the Theory of the Heated Duct Radiator

Description: A method is developed with no neglect of certain factors in mass flow of air and in the drag of the heated radiator, i.e., one under actual operating conditions, as compared with the corresponding values in the cold state, may be simply computed. Although a symmetrical duct radiator has been used to bring out the flow relations, the results apply equally as well to the unsymmetrical radiator shapes usual in airplane construction.
Date: April 1939
Creator: Winter, H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Design of Centrifugal Impeller Blades

Description: This paper restricts itself to radial impellers with cylindrical blades since, as Prasil has shown, the flow about an arbitrarily curved surface of revolution may be reduced to this normal form we have chosen by a relatively simple conformal transformation. This method starts from the simple hypotheses of the older centrifugal impeller theory by first assuming an impeller with an infinite number of blades. How the flow is then modified is then investigated.
Date: July 1939
Creator: Betz, A. & Flügge-Lotz, I.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Drag of Airplane Radiators With Special Reference to Air Heating (Comparison of Theory and Experiment)

Description: This report contains a survey of past radiator research. This report also is intended as a systematic comparison of theoretical and experimental radiator drag, with the object of ascertaining the most important loss sources and their interaction in different cases of installation, and to separate the radiator systems which are amenable to calculation, both as regards axial flow and drag. The sources of loss due to the diffuser are to be looked into closely as in many cases they can be of preemi… more
Date: May 1939
Creator: Göthert, B.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Dynamic Stability of a Helicopter With Hinged Rotor Blades

Description: "The present report is a study of the dynamic stability of a helicopter with hinged rotor blades under hovering conditions. While in this case perfect stability can in general not be obtained it is possible by means of design features to prolong the period of the spontaneous oscillations of the helicopter and reduce their amplification, and so approximately assure neutral equilibrium. The possibility of controlled stability of a helicopter fitted with hinged blades is proved by the successful f… more
Date: September 1939
Creator: Hohenemser, K.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Effect of Compressibility on the Pressure Reading of a Prandtl Pitot Tube at Subsonic Flow Velocity

Description: Errors arising from yawed flow were also determined up to 20 degrees angle of attack. In axial flow, the Prandtl pitot tube begins at w/a approx. = 0.8 to give an incorrect static pressure reading, while it records the tank pressure correctly, as anticipated, up to sonic velocity. Owing to the compressibility of the air, the Prandtl pitot tube manifests compression shocks when the air speed approaches velocity of sound. This affects the pressure reading of the instrument. Because of the increas… more
Date: November 1939
Creator: Walchner, O.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Effect of the Masses of the Controls on the Longitudinal Stability With Free Elevator Part 1

Description: In the present report, aerodynamic relations under the effect of the weight moments are investigated, and an example given of the computation of the stability for a practical case. Later, the effects of the masses of the controls on the dynamic longitudinal stability will be considered.
Date: July 1939
Creator: Schmidt, Rudolf
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The effect of the slipstream on an airplane wing

Description: The conditions which must be met at the slipstream boundary are developed, after which it is shown with the aid of the reflection method how these limiting conditions may be complied with in the case of an airfoil in a propeller slipstream in horizontal flow as well as for the propeller in yaw and with allowance for the slipstream rotation. In connection herewith, it is shown how the effective angles of attack and the circulation distribution with due regard to slipstream effect can be predicte… more
Date: November 1939
Creator: Franke, A. & Weinig, F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Effect of Transition in Cross-Sectional Shape on the Development of the Velocity and Pressure Distribution of Turbulent Flow in Pipes

Description: With regard to the change in shape of the cross section while the area remains constant, no investigation results are as yet available. Such an investigation will be the subject of the present paper. For this purpose it is necessary to consider the velocity and pressure relations over each entire cross section so that we are confronted with a three-dimensional problem.
Date: August 1939
Creator: Mayer, Edwin
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Engine Knock and Combustion Chamber Form

Description: The present report is confined to the effect of the combustion chamber shape on engine knock from three angles, namely: 1) The uniformity of flame-front movement as affected by chamber design and position of the spark plug; 2) The speed of advance of the flame as affected by turbulence and vibrations; 3) The reaction processes in the residual charge as affected by the walls.
Date: October 1939
Creator: Zinner, Karl
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Enlarged N.A.C.A. Tank, and Some of Its Work

Description: The most conspicuous of the features of the enlarged N.A.C.A. tank are derived directly from those of the original tank and owe their present form not only to the reasons for their first use but also to the experience obtained with them. As in the original tank, there are: 1) A basin of great length (new 2,880 feet); 2) Rails made of structural H beams, without machining; 3) A towing carriage of very high speed (now 80 mph maximum); 4) Rubber tires on all the wheels, pneumatic on the running wh… more
Date: November 1939
Creator: Truscott, Starr
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Experimental and Analytical Investigation of a Monocoque Wing Model Loaded in Bending

Description: "Bending tests with transverse loads and with pure bending were undertaken on a double-web monocoque wing model in order to establish the relation between the state of stress and the results from the elementary bending theory. The longitudinal stresses in the stiffeners were measured with tensiometers and the shear stresses in the sheet were calculated from them. The measurements were made at both moderate loads with no buckles in the covering and at loads with which the critical stress in the … more
Date: October 1939
Creator: Schapitz, E.; Feller, H. & Köller, H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Experiments on a Slotted Wing

Description: The results of pressure distribution measurements that were made on a model wing section of a Fieseler F 5 R type airplane are presented. Comparison of those model tests with the corresponding flight tests indicates the limitations and also the advantages of wind tunnel investigations, the advantages being particularly that through the variety of measuring methods employed the more complicated flow conditions may also be clarified. A fact brought out in these tests is that even in the case of "… more
Date: March 1939
Creator: Ruden, P.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Forces and Moments on a Yawed Airfoil

Description: "The author elaborates on the flow phenomena, forces and moments on airfoils in yaw. The existing experiments with straight wings (zero dihedral), wings with dihedral, and wings with sweepback are evaluated within the range of sound angles of attack, explained by calculation and generally enlarged" (p. 1).
Date: August 1939
Creator: Hoerner, Sighard
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Hydrodynamic Theory of Detonation

Description: "This report derives equations containing only directly measurable constants for the quantities involved in the hydrodynamic theory of detonation. The stable detonation speed, D, is revealed as having the lowest possible value in the case of positive material velocity, by finding the minimum of the Du curve (u denotes the speed of the gases of combustion). A study of the conditions of energy and impulse in freely suspended detonating systems leads to the disclosure of a rarefaction front travel… more
Date: June 1939
Creator: Langweiler, Heinz
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Ice Formation on Wings

Description: This report makes use of the results obtained in the Gottingen ice tunnel in which the atmospheric conditions are simulated and the process of ice formation photographed. The effect of ice formation is threefold: 1) added weight to the airplane; 2) a change in the lift and drag forces; 3) a change in the stability characteristics.
Date: February 1939
Creator: Ritz, L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Increase of the Specific Load Under Tension, Compression, and Buckling of Welded Steel Tubes in Airplane Construction by Suitable Treatment of Structural Steel and by Proper Design

Description: Report presenting some considerations and test results that may lead to higher tension, compression, and buckling stresses than is possible with the welded-steel-tube struts of the usual familiar construction. The new construction method makes possible a considerably better material utilization and hence a saving in weight.
Date: October 1939
Creator: Müller, J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Investigation of the Lift Distribution Over the Separate Wings of a Biplane

Description: "An investigation is made of the mutual interference of the wings of a biplane under the general assumption that each wing may be replaced by a vortex system of the type given by the Prandtl wing theory. The additional velocities induced at each wing by the presence of the other are determined by the Biot-Savart law and converted into an equivalent change in the angle of attack, the effect being that of an additional twist given to the wings in changing their lift distributions. The lift distri… more
Date: March 1939
Creator: Küchemann, D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Investigations and Experiments in the Guidonia Wind Tunnel

Description: This paper is a presentation of the experiments and equipment used in investigations at the Guidonia wind tunnel. The equipment consisted of: a number of subsonic and supersonic cones, an aerodynamic balance, and optical instruments operating on the Schlieren and interferometer principle.
Date: July 1939
Creator: Ferri, Antonio
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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