101 Matching Results

Search Results

Results: 1 - 24 next
open access

Correlation, Evaluation, and Extension of Linearized Theories for Tire Motion and Wheel Shimmy

Description: "An evaluation is made of the existing theories of a linearized tire motion and wheel shimmy. It is demonstrated that most of the previously published theories represent varying degrees of approximation to a summary theory developed in this report which is a minor modification of the basic theory of Von Schlippe and Dietrich. In most cases where strong differences exist between the previously published theories and summary theory, the previously published theories are shown to possess certain d… more
Date: January 13, 1956
Creator: Smiley, Robert F.
Partner: UNT Libraries Government Documents Department
open access

Interaction of a Free Flame Front With a Turbulence Field

Description: "Small-perturbation spectral-analysis techniques are used to obtain the root-mean-square flame-generated turbulence velocities and the attenuating pressure fluctuations stemming from interaction of a constant-pressure flame front with a field of isotropic turbulence in the absence of turbulence decay processes. The anisotropic flame-generated turbulence velocities are found to be of about the same intensity as those of the incident isotropic turbulence, the lateral turbulence velocities being a… more
Date: January 25, 1955
Creator: Tucker, Maurice
Partner: UNT Libraries Government Documents Department
open access

The hydrodynamic characteristics of modified rectangular flat plates having aspect ratios of 1.00, 0.25, and 0.125 and operating near a free water surface

Description: Report presents the results of an investigation conducted to determine the hydrodynamic forces and moments acting on modified rectangular flat plates with aspect ratios of 1.00, 0.25, and 0.125 mounted on a single strut and operating at several depths of submersion. A simple method has been developed by modification of Falkner's vortex-lattice theory which enables the prediction of the lift characteristics in unseparated flow at large depths. This method shows good agreement with experimental d… more
Date: January 19, 1954
Creator: Wadlin, Kenneth L.; Ramsen, John A. & Vaughan, Victor L., Jr.
Partner: UNT Libraries Government Documents Department
open access

On the flow of a compressible fluid by the hodograph method 1: unification and extension of present-day results

Description: From Summary: "Elementary basic solutions of the equations of motion of a compressible fluid in the hodograph variables are developed and used to provide a basis for comparison, in the form of velocity correction formulas, of corresponding compressible and incompressible flows. The known approximate results of Chaplygin, Von Karman and Tsien, Temple and Yarwood, and Prandtl and Glauert are unified by means of the analysis of the present paper. Two new types of approximations, obtained from the … more
Date: January 12, 1944
Creator: Garrick, I. E. & Kaplan, Carl
Partner: UNT Libraries Government Documents Department
open access

Effect of body nose shape on the propulsive efficiency of a propeller

Description: Report presents the results of an investigation of the propulsive efficiency of three adjustable propellers of 10-foot diameter operated in front of four body nose shapes, varying from streamline nose that continued through the propeller plane in the form of a large spinner to a conventional open-nose radial-engine cowling. One propeller had airfoil sections close to the hub, the second had conventional round blade shanks, and the third differed from the second only in pitch distribution. The b… more
Date: January 29, 1940
Creator: Stickle, George W.; Crigler, John L. & Naiman, Irven
Partner: UNT Libraries Government Documents Department
open access

Determination of optimum plan forms for control surfaces

Description: Solutions found for a range of airfoil plan forms indicate that, regardless of the characteristics of the tail surface, the chord of the rudder or of the elevator should be very nearly constant over its span. The optimum ailerons are also of a characteristic shape, varying little with the plan form of the wing.
Date: January 30, 1941
Creator: Jones, Robert T. & Cohen, Doris
Partner: UNT Libraries Government Documents Department
open access

Investigation at low speeds of the effect of aspect ratio and sweep on rolling stability derivatives of untapered wings

Description: A low-scale wind-tunnel investigation was conducted in rolling flow to determine the effects of aspect ratio and sweep (when varied independently) on the rolling stability derivatives for a series of untapered wings. The rolling-flow equipment of the Langley stability tunnel was used for the tests. The data of the investigation have been used to develop a method of accounting for the effects of the drag on the yawing moment due to rolling throughout the lift range.
Date: January 19, 1949
Creator: Goodman, Alex & Fisher, Lewis R.
Partner: UNT Libraries Government Documents Department
open access

Application of Radial-Equilibrium Condition to Axial-Flow Compressor and Turbine Design

Description: "Basic general equations governing the three-dimensional compressible flow of gas through a compressor or turbine are given in terms of total enthalpy, entropy, and velocity components of the gas. Two methods of solution are obtained for the simplified, steady axially symmetric flow; one involves the use of a number of successive planes normal to the axis of the machine and short distances apart, and the other involves only three stations for a stage in which an appropriate radial-flow path is … more
Date: January 1, 1949
Creator: Wu, Chung-Hua & Wolfenstein, Lincoln
Partner: UNT Libraries Government Documents Department
open access

Laminar mixing of a compressible fluid

Description: From Summary: "A theoretical investigation of the velocity profiles for laminar mixing of a high-velocity stream with a region of fluid at rest has been made assuming that the Prandtl number is unity. A method which involves only quadratures is presented for calculating the velocity profile in the mixing layer for an arbitrary value of the free-stream Mach number. Detailed velocity profiles have been calculated for free-stream Mach numbers of 0, 1, 2, 3, and 5."
Date: January 5, 1949
Creator: Chapman, Dean R.
Partner: UNT Libraries Government Documents Department
open access

Investigation with an interferometer of the turbulent mixing of a free supersonic jet

Description: The free turbulent mixing of a supersonic jet of Mach number 1.6 has been experimentally investigated. An interferometer, of which a description is given, was used for the investigation. Density and velocity distributions through the mixing zone have been obtained. It was found that there was similarity in distribution at the cross sections investigated and that, in the subsonic portion of the mixing zone, the velocity distribution fitted the theoretical distribution for incompressible flow. It… more
Date: January 21, 1949
Creator: Gooderum, Paul B.; Wood, George P. & Brevoort, Maurice J.
Partner: UNT Libraries Government Documents Department
open access

The use of source-sink and doublet distributions extended to the solution of boundary-value problems in supersonic flow

Description: "A direct analogy is established between the use of source-sink and doublet distributions in the solution of specific boundary-value problems in subsonic wing theory and the corresponding problems in supersonic theory. The correct concept of the "finite part" of an integral is introduced and used in the calculation of the improper integrals associated with supersonic doublet distributions. The general equations developed are shown to include several previously published results and particular e… more
Date: January 1948
Creator: Heaslet, Max A. & Lomax, Harvard
Partner: UNT Libraries Government Documents Department
open access

Estimation of F-3 and F-4 knock-limited performance ratings for ternary and quaternary blends containing triptane or other high-antiknock aviation-fuel blending agents

Description: Charts are presented that permit the estimation of F-3 and F-4 knock-limited performance ratings for certain ternary and quaternary fuel blends. Ratings for various ternary and quaternary blends estimated from these charts compare favorably with experimental F-3 and F-4 ratings. Because of the unusual behavior of some of the aromatic blends in the F-3 engine, the charts for aromatic-paraffinic blends are probably less accurate than the charts for purely paraffinic blends.
Date: January 20, 1945
Creator: Barnett, Henry C.
Partner: UNT Libraries Government Documents Department
open access

Analysis of variation of piston temperature with piston dimensions and undercrown cooling

Description: From Summary: "A theoretical analysis is presented that permits estimation of the changes in piston-temperature distribution induced by variations in the crown thickness, the ring-groove-pad thickness, and the undercrown surface heat-transfer coefficient. The analysis consists of the calculation of operating temperatures at various points in the piston body on the basis of the experimentally determined surface heat-transfer coefficients and boundary-region temperatures, as well as arbitrarily s… more
Date: January 15, 1948
Creator: Sanders, J. C. & Schramm, W. B.
Partner: UNT Libraries Government Documents Department
open access

Interference Method for Obtaining the Potential Flow Past an Arbitrary Cascade of Airfoils

Description: "A procedure is presented for obtaining the pressure distribution on an arbitrary airfoil section in cascade in a two-dimensional, incompressible, and nonviscous flow. The method considers directly the influence on a given airfoil of the rest of the cascade and evaluates this interference by an iterative process, which appeared to converge rapidly in the cases tried (about unit solidity, stagger angles of 0 degree and 45 degrees). Two variations of the basic interference calculations are descri… more
Date: January 10, 1947
Creator: Katzoff, S.; Finn, Robert S. & Laurence, James C.
Partner: UNT Libraries Government Documents Department
open access

Calculations of Economy of 18-Cylinder Radial Aircraft Engine With Exhaust-Gas Turbine Geared to the Crankshaft

Description: Calculations based on dynamometer test-stand data obtained on an 18-cylinder radial engine were made to determine the improvement in fuel consumption that can be obtained at various altitudes by gearing an exhaust-gas turbine to the engine crankshaft in order to increase the engine-shaft work.
Date: January 1, 1945
Creator: Hannum, Richard W. & Zimmerman, Richard H.
Partner: UNT Libraries Government Documents Department
open access

Quantitative Treatment of the Creep of Metals by Dislocation and Rate-Process Theories

Description: "An equation for the steady-state rate of creep has been derived by applying the theory of dislocations to the creep of pure metals. The form of this equation is in agreement with empirical equations describing creep rates. The theory was also used to predict the dependence of steady-state rate of creep on physical constants of the material and good agreement was obtained with data in the literature for pure annealed metals" (p. 169).
Date: January 1, 1946
Creator: Nowick, A. S. & Machlin, E. S.
Partner: UNT Libraries Government Documents Department
open access

An Analysis of the Full-Floating Journal Bearing

Description: Report discussing an analysis of the operating characteristics of a full-floating journal bearing, a bearing in which a floating sleeve is located between the journal and bearing surfaces, is presented together with charts from which the performance of such bearings may be predicted.
Date: January 1, 1947
Creator: Shaw, M. C. & Nussdorfer, T. J., Jr.
Partner: UNT Libraries Government Documents Department
open access

Effect of aspect ratio on the air forces and moments of harmonically oscillating thin rectangular wings in supersonic potential flow

Description: This report treats the effect of aspect ratio on the air forces and moments of an oscillating flat rectangular wing in supersonic potential flow. The linearized velocity potential for the wing undergoing sinusoidal torsional oscillations simultaneously with sinusoidal vertical translations is derived in the form of a power series in terms of a frequency parameter. The series development is such that the differential equation for the velocity potential is satisfied to the required power of the f… more
Date: January 6, 1950
Creator: Watkins, Charles E.
Partner: UNT Libraries Government Documents Department
open access

Correlation of physical properties with molecular structure for some dicyclic hydrocarbons having high thermal-energy release per unit volume -- 2-alkylbiphenyl and the two isomeric 2-alkylbicyclohexyl series

Description: Three homologous series of related dicyclic hydrocarbons are presented for comparison on the basis of their physical properties, which include net heat of combustion, density, melting point, boiling point, and kinematic viscosity. The three series investigated include the 2-n-alkylbiphenyl, 2-n-alkylbicyclohexyl (high boiling), and 2-n-alkylbiphenyls (low boiling) series through c sub 16, in addition to three branched-chain (isopropyl, sec-butyl, and isobutyl) 2-alkylbiphenyls and their corresp… more
Date: January 25, 1951
Creator: Goodman, Irving A. & Wise, Paul H.
Partner: UNT Libraries Government Documents Department
open access

The Langley annular transonic tunnel

Description: Report describes the development of the Langley annular transonic tunnel, a facility in which test Mach numbers from 0.6 to slightly over 1.0 are achieved by rotating the test model in an annular passage between two concentric cylinders. Data obtained for two-dimensional airfoil models in the Langley annular transonic tunnel at subsonic and sonic speeds are shown to be in reasonable agreement with experimental data from other sources and with theory when comparisons are made for nonlifting cond… more
Date: January 19, 1953
Creator: Habel, Louis W.; Henderson, James H. & Miller, Mason F.
Partner: UNT Libraries Government Documents Department
open access

Analysis of the effects of wing interference on the tail contributions to the rolling derivatives

Description: From Introduction: "This report presents calculations of the angularity of the air stream with respect to the vertical tail for a rolling airplane, the interference effects of the wing being taken into account. A discussion of the factors which enter into the calculations is given and equations for applying the side-wash results to the determination of the tail contributions to the rolling-stability derivatives are included. The results are compared with some available experimental data."
Date: January 24, 1951
Creator: Michael, William H., Jr.
Partner: UNT Libraries Government Documents Department
open access

Hydrodynamic impact of a system with a single elastic mode 2: comparison of experimental force and response with theory

Description: From Summary: "Hydrodynamic impact tests were made on an elastic model approximating a two-mass spring system to determine experimentally the effects of structural flexibility on the hydrodynamic loads encountered during seaplane landing impacts and to correlate the results with theory. A flexible seaplane was represented by a two-mass spring system consisting of a rigid prismatic float connected to a rigid upper mass by an elastic structure. The model had a ratio of sprung mass to hull mass of… more
Date: January 30, 1951
Creator: Miller, Robert W. & Merten, Kenneth F.
Partner: UNT Libraries Government Documents Department
open access

A Lift-Cancellation Technique in Linearized Supersonic-Wing Theory

Description: "A lift-cancellation technique is presented for determining load distributions on thin wings at supersonic speeds. The loading on a wing having a prescribed plan form is expressed as the loading of a known related wing (such as a two-dimensional or triangular wing) minus the loading of an appropriate cancellation wing. The lift-cancellation technique can be used to find the loading on a large variety of wings. Applications to swept wings having curvilinear plan forms and to wings having reentra… more
Date: January 16, 1950
Creator: Mirels, Harold
Partner: UNT Libraries Government Documents Department
open access

Experimental determination of effects of frequency and amplitude on the lateral stability derivatives for a delta, a swept, and unswept wing oscillating in yaw

Description: "Three wing models were oscillated in yaw about their vertical axes to determine the effects of systematic variations of frequency and amplitude of oscillation on the in-phase and out-of-phase combination lateral stability derivatives resulting from this motion. The tests were made at low speeds for a 60 degree delta wing, a 45 degree swept wing, and an unswept wing; the swept and unswept wings had aspect ratios of 4. The results indicate that large changes in the magnitude of the stability der… more
Date: January 6, 1956
Creator: Fisher, Lewis R.
Partner: UNT Libraries Government Documents Department
Back to Top of Screen