UNT Libraries Government Documents Department - 1,423 Matching Results

Search Results

prev Results: 11 - 34 next
open access

Flow and Drag Formulas for Simple Quadrics

Description: The pressure distribution and resistance found by theory and experiment for simple quadrics fixed in an infinite uniform stream of practically incompressible fluid are calculated. The experimental values pertain to air and some liquids, especially water; the theoretical refer sometimes to perfect, again to viscid fluids. Formulas for the velocity at all points of the flow field are given. Pressure and pressure drag are discussed for a sphere, a round cylinder, the elliptic cylinder, the prolate… more
Date: December 1979
Creator: Zahm, A. F.
Item Type: Refine your search to only Report
open access

Flow and Force Equations for a Body Revolving in a Fluid

Description: A general method for finding the steady flow velocity relative to a body in plane curvilinear motion, whence the pressure is found by Bernoulli's energy principle is described. Integration of the pressure supplies basic formulas for the zonal forces and moments on the revolving body. The application of the steady flow method for calculating the velocity and pressure at all points of the flow inside and outside an ellipsoid and some of its limiting forms is presented and graphs those quantities … more
Date: December 1979
Creator: Zahm, A. F.
Item Type: Refine your search to only Report
open access

General Potential Theory of Arbitrary Wing Sections

Description: The problem of determining the two dimensional potential flow around wing sections of any shape is examined. The problem is condensed into the compact form of an integral equation capable of yielding numerical solutions by a direct process. An attempt is made to analyze and coordinate the results of earlier studies relating to properties of wing sections. The existing approximate theory of thin wing sections and the Joukowski theory with its numerous generalizations are reduced to special cases… more
Date: November 4, 1932
Creator: Theodorsen, T. & Garrick, I. E.
Item Type: Refine your search to only Report
open access

Impingement of Cloud Droplets on a Cylinder and Procedure for Measuring Liquid-Water Content and Droplet Sizes in Supercooled Clouds by Rotating Multicylinder Method

Description: "Evaluation of the rotating multicylinder method for the measurement of droplet-size distribution, volume-median droplet size, and liquid-water content in clouds showed that small uncertainties in the basic data eliminate the distinction between different cloud droplet-size distributions and are a source of large errors in the determination of the droplet size. Calculations of the trajectories of cloud droplets in incompressible and compressible flow fields around a cylinder were performed on a… more
Date: September 5, 1952
Creator: Brun, R. J.; Lewis, W.; Perkins, P. J. & Serafini, J. S.
Item Type: Refine your search to only Report
open access

Determination of Stresses in Gas-turbine Disks Subjected to Plastic Flow and Creep

Description: From Summary: "A finite-difference method previously presented for computing elastic stresses in rotating disks is extended to include the computation of the disk stresses when plastic flow and creep are considered. A finite-difference method is employed to eliminate numerical integration and to permit nontechnical personnel to make the calculations with a minimum of engineering supervision. Illustrative examples are included to facilitated explanation of the procedure by carrying out the compu… more
Date: 1948
Creator: Millenson, M. B. & Manson, S. S.
Item Type: Refine your search to only Report
open access

Design of Wind Tunnels and Wind Tunnel Propellers, 2

Description: Report presenting a continuation of a previous study in order to supply further data to the designers of wind tunnels. Particular emphasis was placed on the study of directional variation in the wind stream. The results indicated that placing radial vanes directly before the propeller actually increased the efficiency of the tunnel to a considerable extent.
Date: 1921
Creator: Norton, F. H. & Warner, E. P.
Item Type: Refine your search to only Report
open access

On the plane potential flow past a lattice of arbitrary airfoils

Description: The two-dimensional, incompressible potential flow past a lattice of airfoils of arbitrary shape is investigated theoretically. The problem is treated by usual methods of conformal mapping in several stages, one stage corresponding to the mapping of the framework of the arbitrary line lattice and another significant stage corresponding to the Theodorsen method for the mapping of the arbitrary single wing profile into a circle. A particular feature in the theoretical treatment is the special han… more
Date: November 19, 1943
Creator: Garrick, I. E.
Item Type: Refine your search to only Report
open access

Icing-protection requirements for reciprocating-engine induction system

Description: From Summary: "Despite the development of relatively ice-free fuel-metering systems, the widespread use of alternate and heated-air intakes, and the use of alcohol for emergency de-icing, icing of aircraft-engine induction systems is a serious problem. Investigations have been made to study and to combat all phases of this icing problem. From these investigations, criterions for safe operation and for design of new induction systems have been established. The results were obtained from laborato… more
Date: June 20, 1949
Creator: Coles, Willard D.; Rollin, Vern G. & Mulholland, Donald R.
Item Type: Refine your search to only Report
open access

Line-Vortex Theory for Calculation of Supersonic Downwash

Description: "The perturbation field induced by a line vortex in a supersonic stream and the downwash behind a supersonic lifting surface are examined to establish approximate methods for determining the downwash behind supersonic wings. Lifting-lines methods are presented for calculating supersonic downwash. A bent lifting-line method is proposed for computing the downwash field behind swept wings. When applied to triangular wings with subsonic leading edges, this method gives results that, in general, are… more
Date: April 29, 1949
Creator: Mirels, Harold & Haefeli, Rudolph C.
Item Type: Refine your search to only Report
open access

A radar method of calibrating airspeed installations on airplanes in maneuvers at high altitudes and at transonic and supersonic speeds

Description: A method of calibrating the static-pressure source of a pitot static airspeed installation on an airplane in level flight, dives, and other maneuvers at high altitude and at transonic and supersonic speeds is described. The method principally involves the use of radar-phototheodolite tracking equipment. The various sources of error in the method are discussed and sample calibrations are included.
Date: August 31, 1949
Creator: Zalovcik, John A.
Item Type: Refine your search to only Report
open access

The reversibility theorem for thin airfoils in subsonic and supersonic flow

Description: A method introduced by Munk is extended to prove that the light-curve slope of thin wings in either subsonic flow or supersonic flow is the same when the direction of flight of the wing is reversed. It is also shown that the wing reversal does not change the thickness drag, damping-in-roll parameter or the damping-in-pitch parameter.
Date: June 26, 1949
Creator: Brown, Clinton E.
Item Type: Refine your search to only Report
open access

Equilibrium Operating Performance of Axial-Flow Turbojet Engines by Means of Idealized Analysis

Description: "A method of predicting equilibrium operating performance of turbojet engines has been developed, with the assumption of simple model processes for the components. Results of the analysis are plotted in terms of dimensionless parameters comprising critical engine dimensions and over-all operating variables. This investigation was made of an engine in which the ratio of axial inlet-air velocity to compressor-tip velocity is constant, which approximates turbojet engines with axial-flow compressor… more
Date: February 25, 1949
Creator: Sanders, John C. & Chapin, Edward C.
Item Type: Refine your search to only Report
open access

Comparative drag measurements at transonic speeds of rectangular sweptback NACA 65-009 airfoils mounted on a freely falling body

Description: From Summary: "Directly comparable drag measurements have been made of an airfoil with a conventional rectangular plan form and an airfoil with a sweptback plan form mounted on freely falling bodies. Both airfoils had NACA 65-009 sections and were identical in span, frontal area, and chord perpendicular to the leading edge. The sweptback plan form incorporated a sweepback angle of 45 degrees. The data obtained have been used to establish the relation between the airfoil drag coefficients and th… more
Date: August 9, 1945
Creator: Mathews, Charles W. & Thompson, Jim Rogers
Item Type: Refine your search to only Report
open access

Theoretical comparison of several methods of thrust augmentation for turbojet engines

Description: "A theoretical investigation of tail-pipe burning, water injection at the compressor inlet, combination tail-pipe burning plus water injection, bleedoff, and rocket-assist methods thrust augmentation for turbojet engines was made for an engine representative of those in current use. The effect of augmented liquid ratio on augmented thrust ratio and the effects of altitude and flight Mach number on the performance of various methods were determined. The additional take-off weight involved by the… more
Date: October 27, 1948
Creator: Hall, Eldon W. & Wilcox, E. Clinton
Item Type: Refine your search to only Report
open access

Theoretical Study of the Tunnel-Boundary Lift Interference Due to Slotted Walls in the Presence of the Trailing-Vortex System of a Lifting Model

Description: "The equations presented in this report give the interference on the trailing-vortex system of a uniformly loaded finite-span wing in a circular tunnel containing partly open and partly closed walls, with special reference to symmetrical arrangements of the open and closed portions. Methods are given for extending the equations to include tunnel shapes other than circular. The rectangular tunnel is used to demonstrate these methods. The equations are also extended to nonuniformly loaded wings" … more
Date: February 3, 1953
Creator: Matthews, Clarence W.
Item Type: Refine your search to only Report
open access

Theoretical and experimental investigation of heat transfer by laminar natural convection between parallel plates

Description: Results are presented of a theoretical and experimental investigation of heat transfer involving laminar natural convection of fluids enclosed between parallel walls oriented in the direction of the body force, where one wall is heated uniformly, and the other is cooled uniformly. For the experimental work, parallel walls were simulated by using an annulus with an inner-to-outer diameter ratio near 1. The results of the theoretical investigation are presented in the form of equations for the ve… more
Date: 1955
Creator: Lietzke, A. F.
Item Type: Refine your search to only Report
open access

Determination of lateral-stability derivatives and transfer-function coefficients from frequency-response data for lateral motions

Description: A method is presented for determining the lateral-stability derivatives, transfer-function coefficients, and the modes for lateral motion from frequency-response data for a rigid aircraft. The method is based on the application of the vector technique to the equations of lateral motion, so that the three equations of lateral motion can be separated into six equations. The method of least squares is then applied to the data for each of these equations to yield the coefficients of the equations o… more
Date: 1955
Creator: Donegan, James J.; Robinson, Samuel W., Jr. & Gates, Ordway B., Jr.
Item Type: Refine your search to only Report
open access

A Method for the Design of Sweptback Wings Warped to Produce Specified Flight Characteristics at Supersonic Speeds

Description: One of the problems connected with the sweptback wing is the difficulty of controlling the location of the center of pressure and hence the pitching moment. A method is presented for designing a wing to be self-trimming at a given set of flight conditions. Concurrently, the spanwise distribution of load on the wing is made to be approximately elliptical, in an effort to maintain low wing drag.
Date: May 11, 1951
Creator: Tucker, Warren A.
Item Type: Refine your search to only Report
open access

An Investigation of the Maximum Lift of Wings at Supersonic Speeds

Description: This report presents the results of an exploratory investigation carried out in the Langley 9-inch supersonic tunnel to determine the maximum lift of wings operating at supersonic speeds. A variety of wing plan forms of random thickness distributions were tested at Mach numbers of 1.55, 1.90, and 2.32 and at Reynolds numbers varying between 0.74 x 10(6) and 0.27 x 10(6) at angles of attack ranging from zero up through the angle at which maximum lift occurred. Subsequent pressure-distribution te… more
Date: 1955
Creator: Gallagher, James J. & Mueller, James N.
Item Type: Refine your search to only Report
open access

Calculated spanwise lift distributions, influence functions, and influence coefficients for unswept wings in subsonic flow

Description: Spanwise lift distributions have been calculated for nineteen unswept wings with various aspect ratios and taper ratios and with a variety of angle-of-attack or twist distributions, including flap and aileron deflections, by means of the Weissinger method with eight control points on the semispan. Also calculated were aerodynamic influence coefficients which pertain to a certain definite set of stations along the span, and several methods are presented for calculating aerodynamic influence func… more
Date: May 5, 1953
Creator: Diederich, Franklin W. & Zlotnick, Martin
Item Type: Refine your search to only Report
open access

Exact solutions of laminar-boundary-layer equations with constant property values for porous wall with variable temperature

Description: From Summary: "Exact solution of the laminar-boundary-layer equations for wedge-type flow with constant property values are presented for transpiration-cooled surfaces with variable wall temperatures. The difference between wall and stream temperature is assumed proportional to a power of the distance from the leading edge. Solutions are given for a Prandtl number of 0.7 and ranges of pressure-gradient, cooling-air-flow, and wall-temperature-gradient parameters. Boundary-layer profiles, dimensi… more
Date: July 15, 1954
Creator: Donoughe, Patrick L. & Livingood, John N. B.
Item Type: Refine your search to only Report
open access

Generalized Indical Forces on Deforming Rectangular Wings in Supersonic Flight

Description: "A method is presented for determining the time-dependent flow over a rectangular wing moving with a supersonic forward speed and undergoing small vertical distortions expressible as polynomials involving spanwise and chordwise distances. The solution for the velocity potential is presented in a form analogous to that for steady supersonic flow having the familiar "reflected area" concept discovered by Evvard. Particular attention is paid to indicial-type motions and results are expressed in te… more
Date: June 30, 1954
Creator: Lomax, Harvard; Fuller, Franklyn B. & Sluder, Loma
Item Type: Refine your search to only Report
open access

NACA Transonic Wind-Tunnel Test Sections

Description: Report presents an approximate subsonic theory for the solid-blockage interference in circular wind tunnels with walls slotted in the direction of flow. This theory indicated the possibility of obtaining zero blockage interference. Tests in a circular slotted tunnel based on the theory confirmed the theoretical predictions.
Date: June 20, 1955
Creator: Wright, Ray H. & Ward, Vernon G.
Item Type: Refine your search to only Report
open access

A Theoretical and Experimental Investigation of the Lift and Drag Characteristics of Hydrofoils at Subcritical and Supercritical Speeds

Description: "A theoretical and experimental investigation at subcavitation speeds was made of the effect of the free-water surface and rigid boundaries on the lift and drag of an aspect-ratio-10 hydrofoil at both subcritical and supercritical speeds and of an aspect ratio-4 hydrofoil at supercritical speeds. Approximate theoretical solutions for the effects of the free-water surface and rigid boundaries on drag at subcritical speeds are developed. An approximate theoretical solution for the effects of thes… more
Date: 1955
Creator: Wadlin, Kenneth L.; Shuford, Charles L., Jr. & McGehee, John R.
Item Type: Refine your search to only Report
Back to Top of Screen