Search Results

open access

Theoretical Damping in Roll and Rolling Moment Due to Differential Wing Incidence for Slender Cruciform Wings and Wing-Body Combinations

Description: "A method of analysis based on slender-wing theory is developed to investigate the characteristics in roll of slender cruciform wings and wing-body combinations. The method makes use of the conformal mapping processes of classical hydrodynamics which transform the region outside a circle and the region outside an arbitrary arrangement of line segments intersecting at the origin. The method of analysis may be utilized to solve other slender cruciform wing-body problems involving arbitrarily assi… more
Date: 1952
Creator: Adams, Gaynor J. & Dugan, Duane W.
open access

Method and Graphs for the Evaluation of Air-Induction Systems

Description: "Graphs have been developed for rapid evaluation of air-induction systems from considerations of their aerodynamic-performance parameters in combination with power-plant characteristics. The graphs cover the range of supersonic Mach numbers to 3.0. Examples are presented for an air-induction system and engine combination of two Mach numbers and two altitudes in order to illustrate the method and application of the graphs" (p. 793).
Date: February 19, 1952
Creator: Brajnikoff, George B.
open access

Flight investigation of a mechanical feel device in an irreversible elevator control system of a large airplane

Description: Report presents the results of measurements of the longitudinal stability and control characteristics of a large airplane using a mechanical feel device in combination with a booster incorporated in the elevator-control system. Tests were made to investigate the feasibility of eliminating the aerodynamic control forces through use of a booster and of providing control-feel forces mechanically. The feel device consisted of a centering spring which restrained the control stick through a linkage w… more
Date: 1952
Creator: Brown, B. Porter; Chilton, Robert G. & Whitten, James B.
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.
open access

An Experimental Investigation of Transonic Flow Past Two-Dimensional Wedge and Circular-Arc Sections Using a Mach-Zehnder Interferometer

Description: Report presents the results of interferometer measurements of the flow field near two-dimensional wedge and circular-arc sections of zero angle of attack at high-subsonic and low-supersonic velocities. Both subsonic flow with local supersonic zone and supersonic flow with detached shock wave have been investigated. Pressure distributions and drag coefficients as a function of Mach number have been obtained.
Date: 1952
Creator: Bryson, Arthur Earl, Jr.
open access

Effects of compressibility on the performance of two full-scale helicopter rotors

Description: Report presents the results of an investigation conducted on the Langley helicopter test tower to determine experimentally the effects of compressibility on the performance and blade pitching moments of two full-scale helicopter rotors. Two sets of rotor blades were tested which differed only in that the blades of one set incorporated -8 degrees of linear twist, whereas the blades of the other set were untwisted. The tests covered a range of tip speeds from 350 to 770 feet per second and a rang… more
Date: 1952
Creator: Carpenter, Paul J.
open access

The Normal Component of the Induced Velocity in the Vicinity of a Lifting Rotor and Some Examples of Its Application

Description: "Paper presents a practical method for computing the approximate values of the normal component of the induced velocity at points in the flow field of a lifting rotor. Tables and graphs of the relative magnitudes of the normal component of the induced velocity are given for selected points in the longitudinal plane of symmetry of the rotor and on the lateral rotor axis. A method is also presented for utilizing the tables and graphs to determine the interference induced velocities arising from t… more
Date: August 11, 1952
Creator: Castles, Walter, Jr. & De Leeuw, Jacob Henri
open access

Airfoil profiles for minimum pressure drag at supersonic velocities -- general analysis with application to linearized supersonic flow

Description: From Summary: "A theoretical investigation is made of the airfoil profile for minimum pressure drag at zero lift in supersonic flow. In the first part of the report a general method is developed for calculating the profile having the least pressure drag for a given auxiliary condition, such as a given structural requirement or a given thickness ratio. To illustrate the general method, the optimum airfoil, defined as the airfoil having minimum pressure drag for a given auxiliary condition, is ca… more
Date: 1952
Creator: Chapman, Dean R.
open access

A study of the characteristics of human-pilot control response to simulated aircraft lateral motions

Description: Report presents the results of studies made in an attempt to provide information on the control operations of the human pilot. These studies included an investigation of the ability of pilots to control simulated unstable yawing oscillations, a study of the basic characteristics of human-pilot control response, and a study to determine whether and to what extent pilot control response can be represented in an analytical form.
Date: March 14, 1952
Creator: Cheatham, Donald C.
open access

Detailed Computational Procedure for Design of Cascade Blades With Prescribed Velocity Distributions in Compressible Potential Flows

Description: "A detailed step-by-step computational outline is presented for the design of two-dimensional cascade blades having a prescribed velocity distribution on the blade in a potential flow of the usual compressible fluid. The outline is based on the assumption that the magnitude of the velocity in the flow of the usual compressible nonviscous fluid is proportional to the magnitude of the velocity in the flow of a compressible nonviscous fluid with linear pressure-volume relation" (p. 1).
Date: 1952
Creator: Costello, George R.; Cummings, Robert L. & Sinnette, John T., Jr.
open access

Initial results of instrument-flying trials conducted in a single-rotor helicopter

Description: "Instrument-flying trials have been conducted in a single-rotor helicopter, the maneuver stability of which could be changed from satisfactory to unsatisfactory. The results indicated that existing longitudinal flying-qualities requirements based on contact flight were adequate for instrument flight at speeds above that for minimum power. However, lateral-directional problems were encountered at low speeds and during precision maneuvers" (p. 1).
Date: March 11, 1952
Creator: Crim, Almer D.; Reeder, John P. & Whitten, James B.
open access

Theoretical and experimental investigation of mufflers with comments on engine-exhaust muffler design

Description: Equations are presented for the attenuation characteristics of single-chamber and multiple-chamber mufflers of both the expansion-chamber and resonator types, for tuned side-branch tubes, and for the combination of an expansion chamber with a resonator. Experimental curves of attenuation plotted against frequency are presented for 77 different mufflers with a reflection-free tailpipe termination. The experiments were made at room temperature without flow; the sound source was a loud-speaker. A … more
Date: October 6, 1952
Creator: Davis, Don D., Jr.; Stokes, George M.; Moore, Dewey & Stevens, George L., Jr.
open access

Experimental investigation of free-convection heat transfer in vertical tube at large Grashof numbers

Description: Report presents the results of an investigation conducted to study free-convection heat transfer in a stationary vertical tube closed at the bottom. The walls of the tube were heated, and heated air in the tube was continuously replaced by fresh cool air at the top. The tube was designed to provide a gravitational field with Grashof numbers of a magnitude comparable with those generated by the centrifugal field in rotating-blade coolant passages (10(8) to 10(13)). Local heat-transfer coefficien… more
Date: June 30, 1952
Creator: Eckert, E. R. G. & Diaguila, A. J.
open access

Method for Calculation of Laminar Heat Transfer in Air Flow Around Cylinders of Arbitrary Cross Section (Including Large Temperature Differences and Transpiration Cooling)

Description: "The solution of heat-transfer problems has become vital for many aeronautical applications. The shapes of objects to be cooled can often be approximated by cylinders of various cross sections with flow normal to the axis as, for instance heat transfer on gas-turbine blades and on air foils heated for deicing purposes. A laminar region always exists near the stagnation point of such objects. A method previously presented by E. R. G. Eckert permits the calculation of local heat transfer around t… more
Date: March 19, 1952
Creator: Eckert, E. R. G. & Livingood, John N. B.
open access

A unified two-dimensional approach to the calculation of three-dimensional hypersonic flows, with application to bodies of revolution

Description: A procedure for calculating three-dimensional steady and nonsteady supersonic flows with the method of characteristics is developed and discussed. An approximate method is deduced from the characteristics method and shown to be of practical value at high supersonic speeds.
Date: August 15, 1952
Creator: Eggers, A. J., Jr. & Savin, Raymond C.
open access

Preliminary Investigation of a New Type of Supersonic Inlet

Description: "A supersonic inlet with supersonic deceleration of the flow entirely outside of the inlet is considered a particular arrangement with fixed geometry having a central body with a circular annular intake is analyzed, and it is shown theoretically that this arrangement gives high pressure recovery for a large range of Mach number and mass flow and, therefore, is practical for use on supersonic airplanes and missiles. Experimental results confirming the theoretical analysis give pressure recoverie… more
Date: 1952
Creator: Ferri, Antonio & Nucci, Louis M.
open access

Effect of Aspect Ratio on the Low-Speed Lateral Control Characteristics of Untapered Low-Aspect-Ratio Wings Equipped With Flap and With Retractable Ailerons

Description: A low-speed wind-tunnel investigation was made to determine the lateral control characteristics of a series of untapered low-aspect-ratio wings. Sealed flap ailerons of various spans and spanwise locations were investigated on unswept wings of aspect ratios 1.13, 1.13, 4.13, and 6.13; and various projections of 0.60-semispan retractable ailerons were investigated on the unsweptback wings of aspect ratios 1.13, 2.13, and 4.13 and on a 45 degree sweptback wing. The retractable ailerons investigat… more
Date: February 8, 1952
Creator: Fischel, Jack; Naeseth, Rodger L.; Hagerman, John R. & O'Hare, William M.
open access

A summary and analysis of the low-speed longitudinal characteristics of swept wings at high Reynolds number

Description: An analysis of the longitudinal characteristics of swept wings which is based on available large-scale low-speed data and supplemented with low-scale data when feasible is presented. The emphasis has been placed on the differentiation of the characteristics by a differentiation between the basic flow phenomenon involved. Insofar as possible all large-scale data available as of August 15, 1951 have been summarized in tabular form for ready reference.
Date: May 14, 1952
Creator: Furlong, G. Chester & McHugh, James G.
open access

Axisymmetric Supersonic Flow in Rotating Impellers

Description: "General equations are developed for isentropic, frictionless, axisymmetric flow in rotating impellers with blade thickness taken into account and with blade forces eliminated in favor of the blade-surface function. It is shown that the total energy of the gas relative to the rotating coordinate system is dependent on the stream function only, and that if the flow upstream of the impeller is vortex-free, a velocity potential exists which is a function of only the radial and axial distances in t… more
Date: 1952
Creator: Goldstein, Arthur W.
open access

An Iterative Transformation Procedure for Numerical Solution of Flutter and Similar Characteristics-Value Problems

Description: "An iterative transformation procedure suggested by H. Wielandt for numerical solution of flutter and similar characteristic-value problems is presented. Application of this procedure to ordinary natural-vibration problems and to flutter problems is shown by numerical examples. Comparisons of computed results with experimental values and with results obtained by other methods of analysis are made" (p. 1).
Date: 1952
Creator: Gossard, Myron L.
open access

Stresses in a Two-Bay Noncircular Cylinder Under Transverse Loads

Description: A method, taking into account the effects of flexibility and based on a general eighth-order differential equation, is presented for finding the stresses in a two-bay, noncircular cylinder the cross section of which can be composed of circular arcs. Numerical examples are given for two cases of ring flexibility for a cylinder of doubly symmetrical (essentially elliptic) cross section, subjected to concentrated radial, moment, and tangential loads. The results paralleled those already obtained f… more
Date: 1952
Creator: Griffith, George E.
open access

Experimental Aerodynamic Derivatives of a Sinusoidally Oscillating Airfoil in Two-Dimensional Flow

Description: "Experimental measurements of the aerodynamic reactions on a symmetrical airfoil oscillating harmonically in a two-dimensional flow are presented and analyzed. Harmonic motions include pure pitch and pure translation, for several amplitudes and superimposed on an initial angle of attack, as well as combined pitch and translation. The apparatus and testing program are described briefly and the necessary theoretical background is presented" (p. 1).
Date: 1952
Creator: Halfman, Robert L.
open access

Reciprocity relations in aerodynamics

Description: "Reverse flow theorems in aerodynamics are shown to be based on the same general concepts involved in many reciprocity theorems in the physical sciences. Reciprocal theorems for both steady and unsteady motion are found as a logical consequence of this approach. No restrictions on wing plan form or flight Mach number are made beyond those required in linearized compressible-flow analysis" (p. 253).
Date: February 19, 1952
Creator: Heaslet, Max A. & Spreiter, John R.
open access

On a Solution of the Nonlinear Differential Equation for Transonic Flow Past a Wave-Shaped Wall

Description: "The Prandtl-Busemann small-perturbation method is utilized to obtain the flow of a compressible fluid past an infinitely long wave-shaped wall. When the essential assumption for transonic flow (that all Mach numbers in the region of flow are nearly unity) is introduced, the expression for the velocity potential takes the form of a power series in the transonic similarity parameter. On the basis of this form of the solution, an attempt is made to solve the nonlinear differential equation for tr… more
Date: 1952
Creator: Kaplan, Carl
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