National Advisory Committee for Aeronautics (NACA) - 321 Matching Results

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Aerodynamic Heat-Power Engine Operating on a Closed Cycle

Description: "Hot-air engines with dynamic compressors and turbines offer new prospects of success through utilization of units of high efficiencies and through the employment of modern materials of great strength at high temperature. Particular consideration is given to an aerodynamic prime mover operating on a closed circuit and heated externally. Increase of the pressure level of the circulating air permits a great increase of limit load of the unit. This also affords a possibility of regulation for whic… more
Date: November 1942
Creator: Ackeret, J. & Keller, D. C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Aerodynamics of Rotating-Wing Aircraft With Blade-Pitch Control

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" (p. 1).
Date: February 1940
Creator: Pflüger, A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Aerodynamics of the Fuselage

Description: "The present report deals with a number of problems, particularly with the interaction of the fuselage with the wing and tail, on the basis of simple calculating method's derived from greatly idealized concepts. For the fuselage alone it affords, in variance with potential theory, a certain frictional lift in yawed flow, which, similar to the lift of a wing of small aspect ratio, is no longer linearly related to the angle of attack. Nevertheless there exists for this frictional lift something l… more
Date: December 1942
Creator: Multhopp, H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Air Transport by Gliders: Some Technical Observations

Description: This short analysis may be useful in determining the real tactical possibilities of "glider trains" and in adopting the course to be followed in possible studies of these questions. In this analysis most prominent are: (a) the power required for the train in level flight; (b) its speed; (c) climb; and (d) the type of airplane best suited for towing as well as design requirements for transport gliders.
Date: June 1941
Creator: Stepniewski, Wieslaw
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Airscrew Gyroscopic Moments

Description: "When flying in a turn or pulling out of a dive, the airscrew exerts a gyroscopic moment on the aircraft, In the case of airscrews with three or more blades, arranged symmetrically, the value of the gyroscopic moment is J(sub x) omega(sub x) omega(sub y), where J(sub x) denotes the axial moment of inertia about the axis of rotation of the airscrew, omega(sub x) the angular upeed of the airscrew about its axis, and omega (sub Y) the rotary speed of the whole aircraft about an axis parallel to th… more
Date: September 1946
Creator: Bock, G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Analysis of Experimental Investigations of the Planing Process of the Surface of Water

Description: Pressure distribution and spray measurements were carried out on rectangular flat and V-bottom planing surfaces. Lift, resistance, and center of pressure data are analyzed and it is shown how these values may be computed for the pure planing procees of a flat or V-bottom suface of arbitrary beam, load and speed, the method being illustrated with the aid of an example.
Date: March 1944
Creator: Sottorf, W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Analytical Theory of the Campini Propulsion System

Description: "The present report deals exclusively with the particular jet-propulsion system mentioned in the cited reports. The discussion is limited, for the present, to the analytical study of the efficiency and the consumption for the case of application to aircraft and to the plotting of the practical operating curves secured theoretically by the use of suitable experimental factors" (p. 1).
Date: March 1942
Creator: Campini, S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Analytical Treatment of Normal Condensation Shock

Description: "The condensation of water vapor in an air has the following consequences: acquisition of heat (liberated heat vaporization; loss of mass on the part of the flowing gas (water vapor is converted to liquid); change in the specific gas constants and of the ratio k of the specific heats (caused by change of gas composition). A discontinuous change of state is therefore connected with the condensation; schlieren photographs of supersonic flows in two-dimensional Laval nozzles show two intersecting … more
Date: July 1947
Creator: Heybey
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Application of the Methods of Gas Dynamics to Water Flows With Free Surface 1: Flows With No Energy Dissipation

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.
Date: March 1940
Creator: Preiswerk, Ernst
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Application of the Methods of Gas Dynamics to Water Flows With Free Surface 2: Flows With Momentum Discontinuities (Hydraulic Jumps)

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.
Date: March 1940
Creator: Preiswerk, Ernst
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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An Approximate Method for Calculation of the Laminar Boundary Layer with Suction for Bodies of Arbitrary Shape

Description: From Summary: "Various ways were tried recently to decrease the friction drag of a body in a flow; they all employ influencing the boundary layer. One of them consists in keeping the boundary layer Laminar by suction; promising tests have been carried out. Since for large Reynolds numbers the friction drag of the laminar boundary layer is much lower than that of the turbulent boundary layer, a considerable saving in drag results from keeping the boundary layer laminar, even with the blower powe… more
Date: March 1949
Creator: Schlichting, H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Axial Superchargers

Description: Improvements, however, have been attained which permit a shortening of the structure without any impairment of the efficiency. The axial supercharger has a better efficiency and a simpler design than the radial supercharger. The relatively narrow range in which it operates satisfactorily should not be a very disturbing factor for practical flight problems. The length of this type of supercharger may be reduced considerably if some impairment in the efficiency is permitted.
Date: August 1944
Creator: Betz, A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Behavior of the Laminar Boundary Layer for Periodically Oscillating Pressure Variation

Description: "The calculation of the phenomena within the boundary layer of bodies immersed in a flow underwent a decisive development on the basis of L. Prandtl's trains of thought, stated more than forth years ago, and by numerous later treatises again and again touching upon them. The requirements of the steadily improving aerodynamics of airplanes have greatly increased with the passing of time and recently research became particularly interested in such phenomena in the boundary layer as are caused by … more
Date: September 1949
Creator: Quick, August Wilhelm & Schröder, K.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Boundary Layer Removal by Suction

Description: Flight-test data and wind-tunnel data on suction profiles are substantially in agreement. The lift values found in the model test can be actually flown and used as a basis for the design. To visualize the action of the suction, the flow conditions with and without suction on the upper surface were photographed; figures 12 to 15 are sections of the film.
Date: April 1941
Creator: Schrenk, O.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Boundary Layer Theory, Part 2, Turbulent Flows

Description: From Summary: "The flow laws of the actual flows at high Reynolds numbers differ considerably from those of the laminar flows treated in the preceding part. These actual flows show a special characteristic, denoted as turbulence. The character of a turbulent flow is most easily understood the case of the pipe flow. Consider the flow through a straight pipe of circular cross section and with a smooth wall. For laminar flow each fluid particle moves with uniform velocity along a rectilinear path." more
Date: April 1949
Creator: Schlichting, H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Buckling Tests on Eccentrically Loaded Beam Columns

Description: "Formulas are obtained for computing the buckling load of rods eccentrically loaded at each end, the computation being extended in particular to the inelastic range. The test results are graphically presented on three sets of curves. Two of these, at least for the elastic range, are independent of the material tested. The third set, which is independent of the material, possesses greater clearness and is therefore used for comparing the test results with the theoretical" (p. 1).
Date: October 1941
Creator: Cassens, J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Buckling Tests With a Spar-Rib Grill

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" (p. 1).
Date: September 1940
Creator: Weinhold, Josef
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Calculation of Centrally Loaded Thin-Walled Columns Above the Buckling Limit

Description: "When thin-walled columns formed from flanged sheet, such as used in airplane construction, are subjected to axial load, their behavior at failure varies according to the slenderness ratio. On long columns the axis deflects laterally while the cross section form is maintained; buckling results. The respective breaking load in the elastic range is computed by Euler's formula and for the plastic range by the Engesser- Karman formula. Its magnitude is essentially dependent upon the length" (p. 1).
Date: April 1945
Creator: Reinitzhuber, F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Calculation of Counterrotating Propellers

Description: "A method for calculation of a counterrotating propeller which is similar to Walchner's method for calculation of the single propeller in the free air stream is developed and compared with measurements. Several dimensions which are important for the design are given end simple formulas for the gain in efficiency derived. Finally a survey of the behavior of the propeller for various operating conditions is presented" (p. 1).
Date: March 1949
Creator: Ginzel, F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Calculation of the Pressure Distribution on Bodies of Revolution in the Subsonic Flow of a Gas Part 1 - Axially Symmetrical Flow

Description: "The present report concerns a method of computing the velocity and pressure distributions on bodies of revolution in axially symmetrical flow in the subsonic range. The differential equation for the velocity potential Phi of a compressible fluid motion is linearized tn the conventional manner, and then put in the form Delta(Phi) = 0 by affine transformation. The quantity Phi represents the velocity potential of a fictitious incompressible flow, for which a constant superposition of sources by … more
Date: July 1947
Creator: Bilharz, Herbert & Hölder, Ernst
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Calculation of Turbulent Expansion Processes

Description: "On the basis of certain formulas recently established by L. Prandtl for the turbulent interchange of momentum in stationary flows, various cases of "free turbulence" - that is, of flows without boundary walls - are treated in the present report. Prandtl puts the apparent shearing stress introduced by the turbulent momentum interchange. This present report deals first with the mixing of an air stream of uniform velocity with the adjacent still air, than with the expansion or diffusion of an air… more
Date: September 1945
Creator: Tollmien, Walter
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Calculations and Experimental Investigations on the Feed-Power Requirement of Airplanes With Boundary-Layer Control

Description: "Calculations and test results are given about the feed-power requirement of airplanes with boundary-layer control. Curves and formulas for the rough estimate of pressure-loss and feed-power requirement are set up for the investigated arrangements which differ structurally and aerodynamically. According to these results the feed power for three different designs is calculated at the end of the report" (p. 1).
Date: September 1947
Creator: Krüger, W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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