UNT Libraries Government Documents Department - 143 Matching Results

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Increasing the Volumetric Efficiency of Diesel Engines by Intake Pipes

Description: "Development of a method for calculating the volumetric efficiency of piston engines with intake pipes. Application of this method to the scavenging pumps of two-stroke-cycle engines with crankcase scavenging and to four-stroke-cycle engines. The utility of the method is demonstrated by volumetric-efficiency tests of the two-stroke-cycle engines with crankcase scavenging. Its practical application to the calculation of intake pipes is illustrated by example" (p. 1).
Date: March 1933
Creator: List, Hans
Item Type: Refine your search to only Report
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Infinitesimal Conical Supersonic Flow

Description: The calculation of infinitesimal conical supersonic flow has been applied first to the simplest examples that have also been calculated in another way. Except for the discovery of a miscalculation in an older report, there was found the expected conformity. The new method of calculation is limited more definitely to the conical case.
Date: March 1947
Creator: Busemann, Adolf
Item Type: Refine your search to only Report
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The Interaction of a Reflected Shock Wave with the Boundary Layer in a Shock Tube

Description: "Ideally, the reflection of a shock from the closed end of a shock tube provides, for laboratory study, a quantity of stationary gas at extremely high temperature. Because of the action of viscosity, however, the flow in the real case is not one-dimensional, and a boundary layer grows in the fluid following the initial shock wave. In this paper simplifying assumptions are made to allow an analysis of the interaction of the shock reflected from the closed end with the boundary layer of the initi… more
Date: March 1958
Creator: Mark, Herman
Item Type: Refine your search to only Report
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The Interdependence of Profile Drag and Lift With Joukowski Type and Related Airfoils

Description: "On the basis of a systematic investigation of Gottingen wind-tunnel data on Joukowski type and related airfoils, it is shown in what manner the profile drag coefficient is dependent on the lift coefficient. The individual factors for the construction of the profile drag polars are given. They afford a more accurate calculation of the performance coefficients of airplane designs than otherwise attainable with the conventional assumption of constant drag coefficient" (p. 1).
Date: March 1935
Creator: Muttray, H.
Item Type: Refine your search to only Report
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Interim Report on Fatigue Characteristics of a Typical Metal Wing

Description: Constant amplitude fatigue tests of seventy-two P-51D "Mustang" wings are reported. The tests were performed by a vibrational loading system and by an hydraulic loading device for conditions with and without varying amounts of pre-load. The results indicate that: (a) the frequency of occurrence of fatigue at any one location is related to the range of the loads applied, (b) the rate of propagation of visible cracks is more or less constant for a large portion of the life of the specimen, and (c… more
Date: March 1956
Creator: Kepert, J. L. & Payne, A. O.
Item Type: Refine your search to only Report
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Investigation of a Rateau Supercharger for a 700-Horsepower Airplane Engine

Description: The Rateau supercharger investigated had, under normal operating conditions, an adiabatic efficiency of 52 percent, the CINA constant-pressure altitude being 6,240 m and the corresponding CINA compression ratio being 2.22. In order to understand the flow conditions in the supercharger, the air velocities at various points, the theoretical delivery heads and a few characteristics were calculated.
Date: March 1934
Creator: Oestrich, Hermann
Item Type: Refine your search to only Report
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Investigation of Aperiodic Time Processes With Autocorrelation and Fourier Analysis

Description: "Autocorrelation and frequency analyses of a series of aperiodic time events, in particular, filtered noises and sibilant sounds, were made. The position and band width of the frequency ranges are best obtained from the frequency analysis, but the energies contained in the several bands are most easily obtained from the autocorrelation function. The mean number of zero crossings of the time function was determined from the curvature of the latter function in the vicinity of the zero crossing, a… more
Date: March 1958
Creator: Exner, Marie Luise
Item Type: Refine your search to only Report
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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
open access

The Law Relating to Air Currents

Description: In the subdivided wing section profile, the diagram of the current is entirely changed and the harmful formation of eddies is avoided through premature deflection. Pressure equalization does not occur between the upper and under sides. This report presents a discussion of the various laws relating to wing design with the conclusion being that lift increases with more acute angles of attack.
Date: March 1921
Item Type: Refine your search to only Report
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The Lift Distribution of Swept-Back Wings

Description: "Two procedures for calculating the lift distribution along the span are given in which a better account is taken of the distribution of circulation over the area than in the Prandtl lifting-line theory. The methods are also applicable to wing sweepback. Calculated results for the two methods were in agreement" (p. 1).
Date: March 1947
Creator: Weissinger, J.
Item Type: Refine your search to only Report
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Maps and Navigation Methods

Description: Different maps and scales are discussed with particular emphasis on their use in aviation. The author makes the observation that current navigation methods are slow and dangerous and should be replaced by scientific methods of navigation based on loxodromy and the use of the compass.
Date: March 1922
Creator: Duval, A.
Item Type: Refine your search to only Report
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Measurement of Knock Characteristics in Spark-Ignition Engines

Description: This paper presents a discussion of three potential sources of error in recording engine knocking which are: the natural oscillation of the membrane, the shock process between test contacts, and the danger of burned contacts. Following this discussion, the paper calls attention to various results which make the bouncing-pin indicator appear fundamentally unsuitable for recording knock phenomena.
Date: March 1940
Creator: Schütz, R.
Item Type: Refine your search to only Report
open access

Measurement of Profile Drag on an Airplane in Flight by the Momentum Method: Part 2

Description: The purpose of this section is to survey the present status of scientific knowledge of the causes which produce drag, in order, if possible, to establish the relation between the individual results and the actual phenomena which demonstrate the fundamental importance of surface conditions. A discussion of the boundary layer is followed by: relations between frictional and form drag, application to profile-drag measurements, and different kinds of roughness. High-pressure wind tunnel tests are d… more
Date: March 1930
Creator: Schrenk, Martin
Item Type: Refine your search to only Report
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Mechanical Control of Airplanes

Description: "Before undertaking a detailed description of an automatic-control mechanism, I will state briefly the fundamental conditions for such devices. These are: 1) it must be sensitive at one or more reference values; 2) it must stop the angular motions of the airplane not produced by the pilot; and 3) it must be possible to switch it off and on by a simple hand lever" (p. 1).
Date: March 1929
Creator: Boykow, H.
Item Type: Refine your search to only Report
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Mechanical Similitude and Turbulence

Description: This report deals with the theory of the vortex street which enables the reproduction of the mechanism of the form resistance with suitable approximation under stated conditions, although such a resistance is precluded in a fluid which is perfectly inviscid. Disregarding for the present the origination of the vortex, the stream attitude in the wake of the body may be described approximately correct by the representation of individual vortices, without transgressing the law governing the motion … more
Date: March 1931
Creator: von Karman, T.
Item Type: Refine your search to only Report
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The Minimum Energy Loss Propeller

Description: "Various cases are presented of the solution of the problem of the most efficient propeller, more general cases being considered than the one by Betz in 1919: namely, that of a propeller under a limiting light load. The problem is solved directly and also with the aid of the Ritz method which became readily applicable after the author proposed a method for the solution of the propeller problem, in general, with the aid of trigonometric series. The design of a propeller with the aid of this meth… more
Date: March 1945
Creator: Poliakhov, N.
Item Type: Refine your search to only Report
open access

Modification of Wing-Section Shape to Assure a Predetermined Change in Pressure Distribution

Description: "In order to find an airfoil for a predetermined pressure distribution, the problem must be posed so that the pressure distribution creates no drag. Another fundamental difficulty is that it is impossible to specify a pressure distribution without first knowing the place where these pressures are to be applied, i.e., the wing-section shape. This difficulty may be avoided by directing the pressure distribution along the contour of the wing section. Then it becomes possible to define the change i… more
Date: March 1935
Creator: Betz, A.
Item Type: Refine your search to only Report
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Motion of Fluids With Very Little Viscosity

Description: Report presenting a discussion of the laws of motion of a fluid with very low viscosity. Mathematical formulas that have been created in order to compensate for this lack of viscosity and the circumstances under which viscosity can be disregarded are provided.
Date: March 1928
Creator: Prandtl, L.
Item Type: Refine your search to only Report
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NACA Conference on Aircraft Loads, Structures, and Flutter

Description: "This document contains reproductions of technical papers on some of the most recent research results on aircraft loads, flutter, and structures from the NACA laboratories. These papers were presented by members of the staff of the NACA laboratories at the Conference held at the Langley Aeronautical Laboratory March 5, 6, and 7, 1957. The primary purpose of this Conference was to convey to contractors of the military services and others concerned with the design of aircraft these recent researc… more
Date: March 5, 1957
Item Type: Refine your search to only Report
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NACA Conference on High-Speed Aerodynamics: A Compilation of Papers Presented

Description: A reproduction of the technical papers presented by staff members of the NACA Laboratories at the NACA Conference on High-Speed Aerodynamics at the Ames Aeronautical Laboratory during March 18-20, 1958. The primary purpose of the conference was to convey to military services and contractors the results of recent research and to provide an opportunity to discuss the results.
Date: 1958-03-18/1958-03-20
Item Type: Refine your search to only Report
open access

New Method of Determining the Polar Curve of an Airplane in Flight

Description: "A fundamental defect of existing methods for the determination of the polar of an airplane in flight is the impossibility of obtaining the thrust or the resistance of the propeller for any type airplane with any type engine. The new method is based on the premise that for zero propeller thrust the mean angle of attack of the blade is approximately the same for all propellers if this angle is reckoned from the aerodynamic chord of the profile section. This angle was determined from flight tests… more
Date: March 1945
Creator: Yegorov, B. N.
Item Type: Refine your search to only Report
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New method of extrapolation of the resistance of a model planing boat to full size

Description: "The previously employed method of extrapolating the total resistance to full size with lambda(exp 3) (model scale) and thereby foregoing a separate appraisal of the frictional resistance, was permissible for large models and floats of normal size. But faced with the ever increasing size of aircraft a reexamination of the problem of extrapolation to full size is called for. A method is described by means of which, on the basis of an analysis of tests on planing surfaces, the variation of the we… more
Date: March 1942
Creator: Sottorf, W.
Item Type: Refine your search to only Report
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