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Relation of Turbojet and Ramjet Combustion Efficiency to Second-Order Reaction Kinetics and Fundamental Flame Speed

Description: Theoretical studies of the turbojet and ramjet combustion process are summarized and the resulting equations are applied to experimental data obtained from various combustor tests. The theoretical treatment assumes that one step in the over-all chain of processes which constitute jet-engine combustion is sufficiently slow to be the rate-controlling step that determines combustion efficiency.
Date: August 5, 1957
Creator: Childs, J. Howard; Reynolds, Thaine W. & Graves, Charles C.
Item Type: Refine your search to only Report
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The Compressible Laminar Boundary Layer with Heat Transfer and Arbitrary Pressure Gradient

Description: "An approximate method for the calculation of the compressible laminar boundary layer with heat transfer and arbitrary pressure gradient, based on Thwaites' correlation concept, is presented. With the definition of dimensionless shear and heat-transfer parameters and an assumed correlation of these parameters in terms of a momentum parameter, a complete system of relations for calculating skin friction and heat transfer results. Knowledge of velocity or temperature profiles is not necessary in … more
Date: February 1, 1955
Creator: Cohen, Clarence B. & Reshotko, Eli
Item Type: Refine your search to only Report
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Similar Solutions for the Compressible Laminar Boundary Layer with Heat Transfer and Pressure Gradient

Description: "Stewartson's transformation is applied to the laminar compressible boundary-layer equations and the requirement of similarity is introduced, resulting in a set of ordinary nonlinear differential equations previously quoted by Stewartson, but unsolved. The requirements of the system are Prandtl number of 1.0, linear viscosity-temperature relation across the boundary layer, an isothermal surface, and the particular distributions of free-stream velocity consistent with similar solutions. This sys… more
Date: October 15, 1954
Creator: Cohen, Clarence B. & Reshotko, Eli
Item Type: Refine your search to only Report
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Formulas for the Supersonic Loading, Lift, and Drag of Flat Swept-Back Wings With Leading Edges Behind the Mach Line

Description: "The method of superposition of linearized conical flows has been applied to the calculation of the aerodynamic properties, in supersonic flight, of thin flat, swept-back wings at an angle of attack. The wings are assumed to have rectilinear plan forms, with tips parallel to the stream, and to taper in the conventional sense. The investigation covers the moderately supersonic speed range where the Mach lines from the leading-edge apex lie ahead of the wing" (p. 1147).
Date: March 15, 1950
Creator: Cohen, Doris
Item Type: Refine your search to only Report
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Experimental and predicted longitudinal and lateral-directional response characteristics of a large flexible 35 degree swept-wing airplane at an altitude of 35,000 feet

Description: Measured and predicted dynamic response characteristics of a large flexible swept-wing airplane to control surface inputs are presented for flight conditions of 0.6 to 0.85 Mach number at an altitude of 35,000 feet. The report is divided into two parts. The first part deals with the response of the airplane to elevator control inputs with principal responses contained in a band of frequencies including the longitudinal short-period mode and several symmetrical structural modes. The second part … more
Date: 1957
Creator: Cole, Henry A., Jr.; Brown, Stuart C. & Holleman, Euclid C.
Item Type: Refine your search to only Report
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Theory of self-excited mechanical oscillations of helicopter rotors with hinged blades

Description: Vibrations of rotary-wing aircraft may derive their energy from the rotation of the rotor rather than from the air forces. A theoretical analysis of these vibrations is described and methods for its application are explained in Chapter one. Chapter two reports the results of an investigation of the mechanical stability of a rotor having two vertically hinged blades mounted upon symmetrical supports, that is, of equal stiffness and mass in all horizontal directions. Chapter three presents the th… more
Date: August 24, 1956
Creator: Coleman, Robert P. & Feingold, Arnold M.
Item Type: Refine your search to only Report
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Full-Scale Investigation of Several Jet-Engine Noise-Reduction Nozzles

Description: "A number of noise-suppression nozzles were tested on full-scale engines. In general, these nozzles achieved noise reduction by the mixing interference of adjacent jets, that is, by using multiple-slot-nozzles. Several of the nozzles achieved reductions in sound power of approximately 5 decibels (nearly 70 percent) with small thrust losses (approx. 1 percent). The maximum sound-pressure level was reduced by as much as 18 decibels in particular frequency bands" (p. 1249).
Date: January 22, 1957
Creator: Coles, Willard D. & Callaghan, Edmund E.
Item Type: Refine your search to only Report
open access

Icing-Protection Requirements for Reciprocating-Engine Induction Systems

Description: Report presenting an investigation of the icing of aircraft-engine induction systems. Criterions for safe operation and for the design of new induction system are established through the investigation. The results were obtained from laboratory investigations of carburetor-supercharger combinations, wind-tunnel investigations of air scoops, multicylinder-engine studies, and flight investigations.
Date: 1950
Creator: Coles, Willard D.; Rollin, Vern G. & Mulholland, Donald R.
Item Type: Refine your search to only Report
open access

Effect of Interaction on Landing-Gear Behavior and Dynamic Loads in a Flexible Airplane Structure

Description: "The effects of interaction between a landing gear and a flexible airplane structure on the behavior of the landing gear and the loads in the structure have been studied by treating the equations of motion of the airplane and the landing gear as a coupled system. The landing gear is considered to have nonlinear characteristics typical of conventional gears, namely, velocity-squared damping, polytropic air-compression springing, and exponential tire force-deflection characteristics. For the case… more
Date: May 5, 1955
Creator: Cook, Francis E. & Milwitzky, Benjamin
Item Type: Refine your search to only Report
open access

Area-Suction Boundary-Layer Control as Applied to the Trailing-Edge Flaps of a 35 Degree Swept-Wing Airplane

Description: "A wind-tunnel investigation was made to determine the effects on the aerodynamic characteristics of a 35 degree swept-wing airplane of applying area-suction boundary-layer control to the trailing-edge flaps. Flight tests of a similar airplane were then conducted to determine the effect of boundary-layer control in the handling qualities and operation of the airplane, particularly during landing. The wind-tunnel and flight tests indicated that area suction applied to the trailing-edge flaps pro… more
Date: May 6, 1958
Creator: Cook, Woodrow L.; Anderson, Seth B. & Cooper, George E.
Item Type: Refine your search to only Report
open access

Free-Stream Boundaries of Turbulent Flows

Description: Report presents the results of an experimental and theoretical study made of the instantaneously sharp and irregular front which is always found to separate turbulent fluid from contiguous "nonturbulent" fluid at a free-stream boundary. This distinct demarcation is known to give an intermittent character to hot-wire signals in the boundary zone. The overall behavior of the front is described statistically in terms of its wrinkle-amplitude growth and its lateral propagation relative to the fluid… more
Date: 1955
Creator: Corrsin, Stanley & Kistler, Alan L.
Item Type: Refine your search to only Report
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.
Item Type: Refine your search to only Report
open access

Investigation of the Laminar Aerodynamic Heat-Transfer Characteristics of a Hemisphere-Cylinder in the Langley 11-inch Hypersonic Tunnel at a Mach Number of 6.8

Description: "A program to investigate the aerodynamic heat transfer of a nonisothermal hemisphere-cylinder has been conducted in the Langley 11-inch hypersonic tunnel at a Mach number of 6.8 and a Reynolds number from approximately 0.14 x 10(6) to 1.06 x 10(6) based on diameter and free-stream conditions. The experimental heat-transfer coefficients were slightly less over the whole body than those predicted by the theory of Stine and Wanlass (NACA technical note 3344) for an isothermal surface. For station… more
Date: March 21, 1956
Creator: Crawford, Davis H. & McCauley, William D.
Item Type: Refine your search to only Report
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.
Item Type: Refine your search to only Report
open access

Theoretical and analog studies of the effects of nonlinear stability derivatives on the longitudinal motions of an aircraft in response to step control deflections and to the influence of proportional automatic control

Description: Through theoretical and analog results the effects of two nonlinear stability derivatives on the longitudinal motions of an aircraft have been investigated. Nonlinear functions of pitching-moment and lift coefficients with angle of attack were considered. Analog results of aircraft motions in response to step elevator deflections and to the action of the proportional control systems are presented. The occurrence of continuous hunting oscillations was predicted and demonstrated for the attitude … more
Date: December 29, 1950
Creator: Curfman, Howard J., Jr.
Item Type: Refine your search to only Report
open access

Method for determining the frequency-response characteristics of an element or system from the system transient output response to a known input function

Description: "A method is presented for the determination of the frequency-response characteristics of an element or system by utilizing the transient output response to a known but arbitrary input to the system. Since the application of special inputs, such as step functions or sinusoids, is often imperfect or impractical, a method for utilizing arbitrary inputs is desirable. Simple flight-test data may be reduced by this method to give the frequency response of an aircraft" (p. 1).
Date: 1950
Creator: Curfman, Howard J., Jr. & Gardiner, Robert A.
Item Type: Refine your search to only Report
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.
Item Type: Refine your search to only Report
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.
Item Type: Refine your search to only Report
open access

Theoretical symmetric span loading due to flap deflection for wings of arbitrary plan form at subsonic speeds

Description: From Summary: "A simplified lifting-surface theory is applied to the problem of evaluating span loading due to flap deflection for arbitrary wing plan forms. With the resulting procedure, the effects of flap deflection on the span loading and associated aerodynamic characteristics can be easily computed for any wing which is symmetrical about the root chord and which has a straight quarter-chord line over the wing semispan. The effects of compressibility and spanwise variation of section lift-c… more
Date: September 22, 1950
Creator: DeYoung, John
Item Type: Refine your search to only Report
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Boron and zirconium from crucible refractories in a complex heat-resistant alloy

Description: In a laboratory study of the factors involved in the influence of induction vacuum melting on 55ni-20cr-15co-4mo-3ti-3al heat resistant alloy, it was found that the major factor was the type of ceramic used as the crucible. The study concluded that trace amounts of boron or zirconium derived from reaction of the melt with the crucible refactories improved creep-rupture properties at 1,600 degrees F. Boron was most effective and, in addition, markedly improved hot-workability.
Date: August 5, 1958
Creator: Decker, R. F.; Rowe, John P. & Freeman, J. W.
Item Type: Refine your search to only Report
open access

Analysis of Turbulent Heat Transfer, Mass Transfer, and Friction in Smooth Tubes at High Prandtl and Schmidt Numbers

Description: From Introduction: "In the analysis given herein, which was made at the NACA Lewis laboratory, the expression for eddy diffusivity given in reference 1 is modified in order to account for the effect of kinematic viscosity in reducing the turbulence in the region close to the wall. The effects of variable viscosity and of length-to-diameter ratio are also investigated."
Date: February 17, 1954
Creator: Deissler, Robert G.
Item Type: Refine your search to only Report
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Direct Measurements of Skin Friction

Description: "A device has been developed to measure local skin friction on a flat plate by measuring the force exerted upon a very small movable part of the surface of the flat plate. These forces, which range from about 1 milligram to about 100 milligrams, are measured by means of a reactance device. The apparatus was first applied to measurements in the low-speed range, both for laminar and turbulent boundary layers. The device was then applied to high-speed subsonic flow and the turbulent-skin-friction … more
Date: June 1, 1951
Creator: Dhawan, Satish
Item Type: Refine your search to only Report
open access

Calculation of the lateral control of swept and unswept flexible wings of arbitrary stiffness

Description: A method similar to that of NACA rep. 1000 is presented for calculating the effectiveness and the reversal speed of lateral-control devices on swept and unswept wings of arbitrary stiffness. Provision is made for using either stiffness curves and root-rotation constants or structural influence coefficients in the analysis. Computing forms and an illustrative example are included to facilitate calculations by means of the method. The effectiveness of conventional aileron configurations and the m… more
Date: April 5, 1951
Creator: Diederich, Franklin W.
Item Type: Refine your search to only Report
open access

The response of an airplane to random atmospheric disturbances

Description: The statistical approach to the gust-load problem, which consists in considering flight through turbulent air to be a stationary random process, is extended by including the effect of lateral variation of the instantaneous gust intensity on the aerodynamic forces. The forces obtained in this manner are used in dynamic analyses of rigid and flexible airplanes free to move vertically, in pitch, and in roll. The effect of the interaction of longitudinal, normal, and lateral gusts on the wind stres… more
Date: November 5, 1956
Creator: Diederich, Franklin W.
Item Type: Refine your search to only Report
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