UNT Libraries Government Documents Department - 20 Matching Results

Search Results

Results: 1 - 20
open access

Analytical Study of Shimmy of Airplane Wheels

Description: The problem of shimmy of a castering wheel, such as the nose wheel of a tricycle gear airplane, is treated analytically. The flexibility of the tire is considered to be the primary cause of shimmy. The rather simple theory developed agrees rather well with previous experimental results. The author suggests that shimmy may be eliminated through a suitable choice of landing gear dimensions in lieu of a damper.
Date: September 1952
Creator: Bourcier de Carbon, Christian
Item Type: Refine your search to only Report
open access

Calculation of the Lateral-Dynamic Stability of Aircraft

Description: "Graphs and formulas are given with the aid of which all the aerodynamic coefficients required for computing the lateral dynamic stability can be determined. A number of numerical examples are given for obtaining the stability derivatives and solving the characteristic-stability equation. Approximate formulas are derived with the aid of which rapid preliminary computations may be made and the stability coefficients corrected for certain modifications of the airplane" (p. 1).
Date: February 1952
Creator: Raikh, A.
Item Type: Refine your search to only Report
open access

Concerning the Flow About Ring-Shaped Cowlings of Finite Thickness: Part 1

Description: "It is shown how one may obtain, in a simple manner, the forms of ring-shaped bodies from existing tables of functions according to the customary method of superposition of flow due to singularities and parallel flow. A number of examples of the forms and pressure distributions of annular source bodies with and without hub body are given, and the inlet conditions of such ring-shaped cowlings are investigated. Furthermore, the annular bodies of finite length are indicated that correspond to Jouk… more
Date: January 1952
Creator: Küchemann, Dietrich
Item Type: Refine your search to only Report
open access

Concerning the Flow About Ring-Shaped Cowlings Part 8: Further Measurements on Annular Profiles

Description: "The measurements of part V (reference 1) of this series of reports, which concerned comparatively long ring profiles, are supplemented by measurements on shorter rings as they are used for shrouded propellers and cowlings of ring-shaped radiators. Mass-flow coefficients and profile drags are given. Furthermore, it has to be determined how far the potential theory describes the flow phenomenon with sufficient accuracy and whether the present theory for the calculation of thin annular profile yi… more
Date: February 1952
Creator: Küchemann, Dietrich & Weber, Johanna
Item Type: Refine your search to only Report
open access

Concerning the Flow About Ring-Shaped Cowlings Part 9: The Influence of Oblique Oncoming Flow on the Incremental Velocities and Air Forces at the Front Part of Circular Cowls

Description: The dependence of the maximum incremental velocities and air forces on a circular cowling on the mass flow and the angle of attack of the oblique flow is determined with the aid of pressure-distribution measurements. The particular cowling tested had been partially investigated in NACA TM 1327.
Date: February 1952
Creator: Küchemann, Dietrich & Weber, Johanna
Item Type: Refine your search to only Report
open access

Development of a Laminar Boundary Layer Behind a Suction Point

Description: A theoretical investigation is made of the development of a laminar boundary layer behind a suction slot that is assumed to cut off part of the boundary layer without exerting any sink effect. The development, which is approximate, is based on the heat conduction equation. The heat conduction equation enters the analysis through a linearization of the Prandtl-Mises form of the boundary-layer equation.
Date: March 1952
Creator: Wuest, Walter
Item Type: Refine your search to only Report
open access

The Effect of High Viscosity on the Flow Around a Cylinder and Around a Sphere

Description: "For the determination of the flow velocity one is accustomed to measure the impact pressure, i.e., the pressure intensity in front of an obstacle. In incompressible fluids the impact pressure is yv(sup 2)/2g if the influence of viscosity can be neglected. Such an influence is appreciable, however, when the Reynolds number corresponding to impact tube radius is under about 100, and must consequently be considered, if the velocity determination is not to be faulty" (p. 1).
Date: June 1952
Creator: Homann, F.
Item Type: Refine your search to only Report
open access

The Excitation of Unstable Perturbations in a Laminar Friction Layer

Description: "With the aid of the method of small oscillations which was used successfully in the investigation of the stability of laminar velocity distributions in the presence of two-dimensional perturbations, the excitation of the unstable perturbations for the Hartree velocity distributions occurring in plane boundary-layer flow for decreasing and increasing pressure is calculated as a supplement to a former report. The results of this investigation are to make a contribution toward calculation of the … more
Date: September 1952
Creator: Pretsch, Joachim
Item Type: Refine your search to only Report
open access

Extension to the Cases of Two Dimensional and Spherically Symmetric Flows of Two Particular Solutions to the Equations of Motion Governing Unsteady Flow in a Gas

Description: "The author previously discovered two interesting particular solutions to the equations of motion describing unsteady flow in a gas confined solely to a one-dimensional duct. These solutions are now extended to cover the more noteworthy cases of central symmetry in two and three dimensions" (p. 1).
Date: June 1952
Creator: Pozzi, Lorenzo
Item Type: Refine your search to only Report
open access

Friction and Wear

Description: From the practical point of view, this analysis shows that each problem of friction or wear requires its particular solution. There is no universal solution; one or other of the factors predominates and defines the choice of the solution. In certain cases, copper alloys of great thermal conductivity are preferred; in others, plastics abundantly supplied with water. Sometimes, soft antifriction metals are desirable to distribute the load; at other times, hard metals with high resistance to abras… more
Date: March 1952
Creator: Pomey, Jacques
Item Type: Refine your search to only Report
open access

Investigations of the Boundary-Layer Control on a Full Scale Swept Wing With Air Bled Off From the Turbojet

Description: "The following account reviews the various stages of a research program relative to the high-lift devices on a swept wing by combined suction and blowing (jet action), with ejectors fed by air bled off (extracted) from the turbojet. After reviewing the essential principles of the boundary-layer control obtained by comparison with theory, the electric analogies and the wind-tunnel tests as well as the essential elements of ejector operations, the writers describe the tests made in the large tunn… more
Date: April 1952
Creator: Rebuffet, Pierre & Poisson-Quinton, P.
Item Type: Refine your search to only Report
open access

On Rotational Conical Flow

Description: Some general properties of isoenergetic rotational conical fields are determined. For such fields, provided the physical parameters of the fluid flow are known on a conical reference surface, it being understood that they satisfy certain imposed conditions, it is shown how to construct the hodographs in the various meridional semiplanes, as the envelope of either the tangents to the hodographs or of the osculatory circles.
Date: February 1952
Creator: Ferrari, Carlo
Item Type: Refine your search to only Report
open access

On the Design of Airfoils in Which the Transition of the Boundary Layer Is Delayed

Description: Memorandum examining the phenomenon of airfoil drag, which is related almost exclusively to skin friction at high speed flight conditions. The primary way to reduce drag is to delay the transition from laminar to turbulent flow in the boundary layer along the surface. A particular airflow design that may delay transition and therefore have fewer problems related to drag are provided.
Date: October 1952
Creator: Tani, Itiro
Item Type: Refine your search to only Report
open access

On the Representation of the Stability Region in Oscillation Problems With the Aid of the Hurwitz Determinants

Description: This report concerns the use of the Hurwitz determinants in defining boundaries of regions where oscillatory phenomena are to be stable or unstable. A simplification is suggested as an aid in reducing the computations usually required, although it is emphasized that point checks in the various regions defined are required using the complete set of Hurwitz determinants or some other complete stability determination.
Date: August 1952
Creator: Sponder, E.
Item Type: Refine your search to only Report
open access

A Simple Numerical Method for the Calculation of the Laminar Boundary Layer

Description: An iteration difference method for the calculation of the incompressible laminar boundary layer is described. The method uses Prandtl's boundary layer equation and the boundary conditions directly and permits the attainment of an arbitrary accuracy. The method has been tested successfully in the continuation of the Blasius profile on the flat plate, on the circular cylinder investigated by Heimenz and on an elliptical cylinder of fineness ratio 1:4. The method makes possible the testing of prev… more
Date: April 1952
Creator: Schröder, K.
Item Type: Refine your search to only Report
open access

Some Experiences Regarding the Nonlinearity of Hot Wires

Description: "We compare here the results of some experiences with the formulas established in our preceding report 'Nonlinear Theory of a Hot-Wire Anemometer.' We shall show that the nonlinear term plays a role as important as the thermal conduction in the calculation of the thermal inertia of the hot wire" (p. 1).
Date: June 1952
Creator: Betchov, R. & Welling, W.
Item Type: Refine your search to only Report
open access

Transition Caused by the Laminar Flow Separation

Description: An experimental investigation of the effects of the geometry of body surface, Reynolds number, stream turbulence, and a roughness element (wire) on the reattachment of separated laminar boundary-layer flow on a bent flat plate is presented and discussed. The flow mechanisms determining reattachment of the boundary layer are analyzed and discussed.
Date: September 1952
Creator: Maekawa, T. & Atsumi, Shoichi
Item Type: Refine your search to only Report
open access

Wind-Tunnel Corrections at High Subsonic Speeds Particularly for an Enclosed Circular Tunnel

Description: A review of existing publications on wind-tunnel corrections is followed by an approximate method for determining the corrections due to model and wake displacement and to lift. Relations are investigated for fuselages and wings of various spans in closed circular tunnels. A comparison is made between the computations and the tests in the DVL high-speed wind tunnel.
Date: February 1952
Creator: Göthert, Bernhard Hermann
Item Type: Refine your search to only Report
Back to Top of Screen