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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.
Partner: UNT Libraries Government Documents Department
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
Partner: UNT Libraries Government Documents Department
open access

Charts for estimating tail-rotor contribution to helicopter directional stability and control in low-speed flight

Description: "Theoretically derived charts and equations are presented by which tail-rotor design studies of directional trim and control response at low forward speed can be conveniently made. The charts can also be used to obtain the main-rotor stability derivatives of thrust with respect to collective pitch and angle of attack at low forward speeds. The use of the charts and equations for tail-rotor design studies is illustrated. Comparisons between theoretical and experimental results are presented. The… more
Date: October 27, 1953
Creator: Amer, Kenneth B. & Gessow, Alfred
Partner: UNT Libraries Government Documents Department
open access

Theoretical Prediction of Pressure Distributions on Nonlifting Airfoils at High Subsonic Speeds

Description: "Theoretical pressure distributions on nonlifting circular-arc airfoils in two-dimensional flows with high subsonic free-stream velocity are found by determining approximate solutions, through an iteration process, of an integral equation for transonic flow proposed by Oswatitsch. The integral equation stems directly from the small-disturbance theory for transonic flow. This method of analysis possesses the advantage of remaining in the physical, rather than the hodograph, variable and can be a… more
Date: November 19, 1953
Creator: Spreiter, John R. & Alksne, Alberta
Partner: UNT Libraries Government Documents Department
open access

Cooperative Investigation of Relationship Between Static and Fatigue Properties of Wrought N-155 Alloy at Elevated Temperatures

Description: Report presents the correlation of extensive data obtained relating properties of wrought N-155 alloy under static, combined static and dynamic, and complete reversed dynamic stress conditions. Time period for fracture ranged from 50 to 500 hours at room temperature, 1,000 degrees, 1,200 degrees, and 1,500 degrees F.
Date: June 15, 1953
Creator: NACA Subcommittee on Power-Plant Materials
Partner: UNT Libraries Government Documents Department
open access

An investigation of the effects of heat transfer on boundary-layer transition on a parabolic body of revolution (NACA RM-10) at a Mach number of 1.61

Description: Report presents the results of an investigation conducted to determine the effects of heat transfer on boundary-layer transition on a parabolic body of revolution (NACA rm-10 without fins) at Mach number of 1.61 and over a Reynolds number range from 2.5 x 10(6) to 35 x 10(6). The maximum cooling of the model used in these tests corresponded to a temperature ratio (ratio of model-surface temperature to free-stream temperature) of 1.12, a value somewhat higher than the theoretical value required … more
Date: February 16, 1953
Creator: Czarnecki, K. R. & Sinclair, Archibald R.
Partner: UNT Libraries Government Documents Department
open access

Studies of the speed stability of a tandem helicopter in forward flight

Description: Flight-test measurements, related analytical studies, and corresponding pilots' opinions of the speed stability of tandem-rotor helicopter are presented. An undesirable instability, evidenced by rearward stick motion with increasing forward speed at constant power, is indicated to be caused by variations with speed of the front-rotor downwash at the rear rotor. An analytical expression for predicting changes in speed stability caused by changes in rotor geometry is derived and constants for use… more
Date: June 4, 1953
Creator: Tapscott, Robert J. & Amer, Kenneth B.
Partner: UNT Libraries Government Documents Department
open access

Plastic Deformation of Aluminum Single Crystals at Elevated Temperatures

Description: "This report describes the results of a comprehensive study of plastic deformation of aluminum single crystals over a wide range of temperatures. The results of constant-stress creep tests have been reported for the temperature range from 400 degrees to 900 degrees F. For these tests, a new capacitance-type extensometer was designed. This unit has a range of 0.30 inch over which the sensitivity is very nearly linear and can be varied from as low a sensitivity as is desired to a maximum of 20 mi… more
Date: December 29, 1953
Creator: Johnson, R. D.; Young, A. P. & Schwope, A. D.
Partner: UNT Libraries Government Documents Department
open access

Theory of wing-body drag at supersonic speeds

Description: "The relation of Whitcomb's "area rule" to the linear formulas for wave drag at lightly supersonic speeds is discussed. By adopting an approximate relation between the source strength and the geometry of a wing-body combination, the wave-drag theory is expressed in terms involving the areas intercepted by oblique planes or Mach planes. The resulting formulas are checked by comparison with the drag measurements obtained in wind-tunnel experiments and in experiments with falling models in free ai… more
Date: July 8, 1953
Creator: Jones, Robert T.
Partner: UNT Libraries Government Documents Department
open access

Dynamics of mechanical feedback-type hydraulic servomotors under inertia loads

Description: "An analysis of the dynamics of mechanical feedback-type hydraulic servomotors under inertia loads is developed and experimental verification is presented. The analysis, which is developed in terms of two physical parameters, yields direct expressions for the following dynamic responses: (1) the transient response to a step input and the maximum cylinder pressure during the transient and (2) the variation of amplitude attenuation and phase shift with the frequency of a sinusoidally varying inpu… more
Date: 1953
Creator: Gold, Harold; Otto, Edward W. & Ransom, Victor L.
Partner: UNT Libraries Government Documents Department
open access

One-Dimensional Analysis of Choked-Flow Turbines

Description: "Turbines for most applications requiring high work output per stage have one or more blade rows which are choked. This analysis indicated that the area ratios and equivalent blade speed are the controlling factors in the design and operation of such turbines. Six criteria are stated that will aid in establishing from test data of multistage turbines which blade rows are choked and which are not" (p. 1).
Date: 1953
Creator: English, Robert E. & Cavicchi, Richard H.
Partner: UNT Libraries Government Documents Department
open access

Deflection and Stress Analysis of Thin Solid Wings of Arbitrary Plan Form with Particular Reference to Delta Wings

Description: "The structural analysis of arbitrary solid cantilever wings by small-deflection thin-plate theory is reduced to the solution of linear ordinary differential equations by the assumption that the chordwise deflections at any spanwise station may be expressed in the form of a power series in which the coefficients are functions of the spanwise coordinate. If the series is limited to the first two and three terms (that is, if linear and parabolic chordwise deflections, respectively, are assumed), … more
Date: 1953
Creator: Stein, Manuel; Anderson, J. Edward & Hedgepeth, John M.
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

An analysis of laminar free-convection flow and heat transfer about a flat plate paralled to the direction of the generating body force

Description: From Introduction: "Although the final equations obtained by this method are the same as those of Schmidt and Beckmann, this more general approach not only clearly demonstrates the significance of all the important parameters and assumptions and hence leads to a better understanding of this type of flow but also indicates the quantitative limitations of the theory. In addition, the numerical solutions of references 2 and 3 are herein extended to cover a more complete range of parameters."
Date: 1953~
Creator: Ostrach, Simon
Partner: UNT Libraries Government Documents Department
open access

Laminar Boundary Layer on Cone in Supersonic Flow at Large Angle of Attack

Description: "The laminar boundary-layer flow about a circular cone at large angles of attack to a supersonic stream has been analyzed in the plane of symmetry by a method applicable in general to the flow about conical bodies. At the bottom of the cone, velocity profiles were obtained showing the expected tendency of the boundary layer to become thinner on the under side of the cone as the angle of attack is increased. At the top of the cone, the analysis failed to yield unique solutions except for small a… more
Date: 1953
Creator: Moore, Franklin K.
Partner: UNT Libraries Government Documents Department
open access

A wind-tunnel investigation of the aerodynamic characteristics of a full-scale supersonic-type three-blade propeller at Mach numbers to 0.96

Description: From Summary: "An investigation of the characteristics of a full-scale supersonic-type propeller has been made in the Langley 16-foot transonic tunnel with the 6000-horsepower propeller dynamometer. The tests covered a range of blade angles from 20.2 degrees to 60.2 degrees at forward Mach numbers up to 0.96. The results showed that envelope efficiency at an advance ratio of 2.8 decreased from 86 percent to 72 percent when the forward Mach number was increased from 0.70 to 0.96."
Date: May 18, 1953
Creator: Evans, Albert J. & Liner, George
Partner: UNT Libraries Government Documents Department
open access

Determination of Mean Camber Surfaces for Wings Having Uniform Chordwise Loading and Arbitrary Spanwise Loading in Subsonic Flow

Description: "The field of a uniformly loaded wing in subsonic flow is discussed in terms of the acceleration potential. It is shown that, for the design of such wings, the slope of the mean camber surface at any point can be determined by a line integration around the wing boundary. By an additional line integration around the wing boundary, this method is extended to include the case where the local section lift coefficient varies with spanwise location (the chordwise loading at every section still remain… more
Date: January 13, 1953
Creator: Katzoff, S.; Faison, M. Frances & DuBose, Hugh C.
Partner: UNT Libraries Government Documents Department
open access

A note on secondary flow in rotating radial channels

Description: "A general vector differential equation for the vorticity component parallel to a streamline is derived for steady, nonviscous, and incompressible flow in a rotating system. This equation is then simplified by restricting it to rotating radial channels and by making further simplifying assumptions. The simplified equation is used to solve for the secondary vorticity, the vorticity component parallel to the streamline, in three special cases involving different streamtube geometries; the results… more
Date: August 31, 1953
Creator: Kramer, James J. & Stanitz, John D.
Partner: UNT Libraries Government Documents Department
open access

Comparison of effectiveness of convection-, transpiration-, and film-cooling methods with air as coolant

Description: From Summary: "Various parts of aircraft propulsion engines that are in contact with hot gases often require cooling. Transpiration and film cooling, new methods that supposedly utilize cooling air more effectively than conventional convection cooling, have already been proposed. This report presents material necessary for a comparison of the cooling requirements of these three methods. Correlations that are regarded by the authors as the most reliable today are employed in evaluating each of t… more
Date: July 9, 1953
Creator: Eckert, E. R. G. & Livingood, John N. B.
Partner: UNT Libraries Government Documents Department
open access

A Special Investigation to Develop a General Method for Three-Dimensional Photoelastic Stress Analysis

Description: The method of strain measurement after annealing is reviewed and found to be satisfactory for the materials available in this country. A new general method is described for the photoelastic determination of the principal stresses at any point of a general body subjected to arbitrary load. The method has been applied to a sphere subjected to diametrical compressive loads. The results show possibilities of high accuracy.
Date: 1953
Creator: Frocht, M. M. & Guernsey, R., Jr.
Partner: UNT Libraries Government Documents Department
open access

On Transonic Flow Past a Wave-Shaped Wall

Description: "This report is an extension of a previous investigation (described in NACA rep. 1069) concerned with the solution of the nonlinear differential equation for transonic flow past a wavy wall. In the present work several new notions are introduced which permit the solution of the recursion formulas arising from the method of integration in series. In addition, a novel numerical tests of convergence, applied to the power series (in transonic similarity parameter) representing the local Mach number… more
Date: 1953
Creator: Kaplan, Carl
Partner: UNT Libraries Government Documents Department
open access

Considerations on the effect of wind-tunnel walls on oscillating air forces for two-dimensional subsonic compressible flow

Description: This report treats the effect of wind-tunnel walls on the oscillating two-dimensional air forces in a compressible medium. The walls are simulated by the usual method of placing images at appropriate distances above and below the wing. An important result shown is that, for certain conditions of wing frequency, tunnel height, and Mach number, the tunnel and wing may form a resonant system so that the forces on the wing are greatly changed from the condition of no tunnel walls. It is pointed out… more
Date: 1953
Creator: Runyan, Harry L. & Watkins, Charles E.
Partner: UNT Libraries Government Documents Department
open access

Analysis of Landing-Gear Behavior

Description: From Summary: "This report presents a theoretical study of the behavior of the conventional type of oleo-pneumatic landing gear during the process of landing impact. The basic analysis is presented in a general form and treats the motions of the landing gear prior to and subsequent to the beginning of shock-strut deflection."
Date: 1953~
Creator: Milwitzky, Benjamin & Cook, Francis E.
Partner: UNT Libraries Government Documents Department
open access

Analytical Derivation and Experimental Evaluation of Short-Bearing Approximation for Full Journal Bearing

Description: From Introduction: "This report extends the short-bearing pressure-distribution function of Michell and Cardullo to give equations for the various bearing characteristics. This short-bearing approximation makes available formulas relating eccentricity ratio to applied load, attitude angle, angular position of peak film pressure to unit pressure on projected area."
Date: June 12, 1953
Creator: DuBois, George B. & Ocvirk, Fred W.
Partner: UNT Libraries Government Documents Department
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