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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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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.
Item Type: Refine your search to only Report
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Analog study of interacting and noninteracting multiple-loop control systems for turbojet engines

Description: The results of an analog investigation of several turbojet-engine control configurations is presented in this report. Both proportional and proportional-plus-integral controllers were studied, and compensating terms for engine interaction were added to the control system. Data were obtained on the stability limits and the transient responses of these various configurations. Analytical expressions in terms of the component transfer functions were developed for the configurations studied, and the… more
Date: 1955
Creator: Pack, George J. & Phillips, W. E., Jr.
Item Type: Refine your search to only Report
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Minimum-drag ducted and pointed bodies of revolution based on linearized supersonic theory

Description: The linearized drag integral for bodies of revolution at supersonic speeds is presented in a double-integral form which is not based on slender-body approximations but which reduces to the equal slender-body expression in the proper limit. With the aid of a suitably chosen auxiliary condition, the minimum-external-wave-drag problem is solved for a transition section connecting two semi-infinite cylinders. The projectile tip is a special case and is compared with the Von Karman projectile tip. C… more
Date: March 1, 1954
Creator: Parker, Hermon M.
Item Type: Refine your search to only Report
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Statistical measurements of contact conditions of 478 transport-airplane landings during routine daytime operations

Description: Statistical measurements of contact conditions have been obtained, by means of a special photographic technique, of 478 landings of present-day transport airplanes made during routine daylight operations in clear air at the Washington National Airport. From the measurements, sinking speeds, rolling velocities, bank angles, and horizontal speeds at the instant before contact have been evaluated and a limited statistical analysis of the results has been made and is reported in this report.
Date: 1955
Creator: Silsby, Norman S.
Item Type: Refine your search to only Report
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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
Item Type: Refine your search to only Report
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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
Item Type: Refine your search to only Report
open access

Effect of ground interference on the aerodynamic and flow characteristics of a 42 degree sweptback wing at Reynolds numbers up to 6.8 x 10(6)

Description: Report presents the results of an investigation of the effects of ground interference on the aerodynamic characteristics of a 42 degree sweptback wing at distances 0.68 and 0.92 of the mean aerodynamic chord from the simulated ground to the 0.25-chord point of the mean aerodynamic chord. Survey data behind the wing, both with and without the simulated ground, are presented in the form of contour charts of downwash, sidewash, and dynamic-pressure ratio at longitudinal stations of 2.0 and 2.8 mea… more
Date: December 17, 1954
Creator: Furlong, G. Chester & Bollech, Thomas V.
Item Type: Refine your search to only Report
open access

Measurement and Analysis of Wing and Tail Buffeting Loads on a Fighter Airplane

Description: "The buffeting loads measured on the wing and tail of a fighter airplane during 194 maneuvers are given in tabular form, along with the associated flight conditions. Measurements were made at altitudes of 30,000 to 10,000 feet and at speeds up to a Mach number of 0.8. Least-squares methods have been used for a preliminary analysis of the data. The agreement between the results of this analysis and the loads measured in stalls is sufficiently good to suggest the examination of the buffeting of o… more
Date: 1955
Creator: Huston, Wilber B. & Skopinski, T. H.
Item Type: Refine your search to only Report
open access

Calculations of Laminar Heat Transfer Around Cylinders of Arbitrary Cross Section and Transpiration-Cooled Walls With Application to Turbine Blade Cooling

Description: "An approximate method for the development of flow and thermal boundary layers in the laminar region on cylinders with arbitrary cross section and transpiration-cooled walls is obtained by the use of Karman's integrated momentum equation and an analogous heat-flow equation. Incompressible flow with constant property values throughout the boundary layer is assumed. The velocity and temperature profiles within the boundary layer are approximated by expressions composed of trigonometric functions"… more
Date: June 22, 1951
Creator: Eckert, E. R. G. & Livingood, J. N. B.
Item Type: Refine your search to only Report
open access

Comparison of performance of experimental and conventional cage designs and materials for 75-millimeter-bore cylindrical roller bearings at high speed

Description: From Summary: "The results of two investigations, one to determine the relative merits of four experimental and two conventional design 75-millimeter-bore (size 215) cylindrical roller bearings and one to determine the relative merits of nodular iron and bronze as cage materials for this size and type of bearing, are presented in this report. Nine test bearings were operated over a range of dn values (product of bearing bore in mm and shaft speed in r.p.m) from 0.3 x 10(6) to 2.3 x 20(6), radia… more
Date: June 30, 1954
Creator: Anderson, William J.; Macks, E. Fred & Nemeth, Zolton N.
Item Type: Refine your search to only Report
open access

Propagation of a free flame in a turbulent gas stream

Description: Effective flame speeds of free turbulent flames were measured by photographic, ionization-gap, and photomultiplier-tube methods, and were found to have a statistical distribution attributed to the nature of the turbulent field. The effective turbulent flame speeds for the free flame were less than those previously measured for flames stabilized on nozzle burners, Bunsen burners, and bluff bodies. The statistical spread of the effective turbulent flame speeds was markedly wider in the lean and r… more
Date: May 7, 1956
Creator: Mickelsen, William R. & Ernstein, Norman E.
Item Type: Refine your search to only Report
open access

Spark ignition of flowing gases

Description: Research conducted at the NACA Lewis Laboratory on ignition of flowing gases by means of long-duration discharges is summarized and analyzed. Data showing the effect of a flowing combustible mixture on the physical and electrical characteristics of spark discharges and data showing the effects of variables on the spark energy required for ignition that has been developed to predict the effect of many of the gas-stream and spark variables is described and applied to a limited amount of experimen… more
Date: June 20, 1956
Creator: Swett, Clyde C., Jr.
Item Type: Refine your search to only Report
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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
Item Type: Refine your search to only Report
open access

Contributions on the Mechanics of Boundary-Layer Transition

Description: "The manner in which flow in a boundary layer becomes turbulent was investigated on a flat plate at wind speeds generally below 100 feet per second. Hot-wire techniques were used, and many of the results are derived from oscillograms of velocity fluctuations in the transition region. Following a presentation of the more familiar aspects of transition, there are presented the very revealing facts discovered while studying the characteristics of artificially produced turbulent spots" (p. 853).
Date: February 28, 1955
Creator: Schubauer, G. B. & Klebanoff, P. S.
Item Type: Refine your search to only Report
open access

Development of craze and impact resistance in glazing plastics by multiaxial stretching

Description: The loss of strength of cast polymethyl methacrylate plastic as a result of crazing is of considerable importance to the aircraft industry. Because of the critical need for basic information on the nature of crazing and the effects of various treatments and environmental conditions on its incidence and magnitude, an investigation of this phenomenon was undertaken. The following factors were examined: (1) the effect of stress-solvent crazing on tensile strength of polymethyl methacrylate; (2) th… more
Date: December 28, 1955
Creator: Kline, G. M.; Wolock, I.; Axilrod, B. M.; Sherman, M. A.; George, D. A. & Cohen, V.
Item Type: Refine your search to only Report
open access

Lift Hysteresis at Stall as an Unsteady Boundary-Layer Phenomenon

Description: "Analysis of rotating stall of compressor blade rows requires specification of a dynamic lift curve for the airfoil section at or near stall, presumably including the effect of lift hysteresis. Consideration of the Magnus lift of a rotating cylinder suggests performing an unsteady boundary-layer calculation to find the movement of the separation points of an airfoil fixed in a stream of variable incidence. The consideration of the shedding of vorticity into the wake should yield an estimate of … more
Date: August 17, 1955
Creator: Moore, Franklin K.
Item Type: Refine your search to only Report
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Intensity, scale, and spectra of turbulence in mixing region of free subsonic jet

Description: Report presents the results of the measurements of intensity of turbulence, the longitudinal and lateral correlation coefficients, and the spectra of turbulence in a 3.5-inch-diameter free jet measured with hot-wire anemometers at exit Mach numbers from 0.2 to 0.7 and Reynolds numbers from 192,000 to 725,000.
Date: April 24, 1956
Creator: Laurence, James C.
Item Type: Refine your search to only Report
open access

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
open access

An analysis of once-per-revolution oscillating aerodynamic thrust loads on single-rotation propellers on tractor airplanes at zero yaw

Description: A simplified procedure is shown for calculating the once-per-revolution oscillating aerodynamic thrust loads on propellers of tractor airplanes at zero yaw. The only flow field information required for the application of the procedure is a knowledge of the upflow angles at the horizontal center line of the propeller disk. Methods are presented whereby these angles may be computed without recourse to experimental survey of the flow field. The loads computed by the simplified procedure are compar… more
Date: March 21, 1955
Creator: Rogallo, Vernon L.; Yaggy, Paul F. & McCloud, John L., III
Item Type: Refine your search to only Report
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Nonlifting Wing-Body Combinations With Certain Geometric Restraints Having Minimum Wave Drag at Low Supersonic Speeds

Description: "Several variational problems involving optimum wing and body combinations having minimum wave drag for different kinds of geometrical restraints are analyzed. Particular attention is paid to the effect on the wave drag of shortening the fuselage and, for slender axially symmetric bodies, the effect of fixing the fuselage diameter at several points or even of fixing whole portions of its shape" (p. 113).
Date: August 4, 1955
Creator: Lomax, Harvard
Item Type: Refine your search to only Report
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An Analysis of the Effects of Aeroelasticity on Static Longitudinal Stability and Control of a Swept-Wing Airplane

Description: From Introduction: "The results of the aforementioned study are presented in this report together with the method of analysis employed. The net stability change is shown together with the individual contributions due to flexibility of wing, tail, and fuselage, both including and neglecting the effect of inertial loads."
Date: March 19, 1951
Creator: Skoog, Richard B.
Item Type: Refine your search to only Report
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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.
Item Type: Refine your search to only Report
open access

Linearized Lifting-Surface and Lifting-Line Evaluations of Sidewash Behind Rolling Triangular Wings at Supersonic Speeds

Description: "The lifting-surface sidewash behind rolling triangular wings has been derived for a range of supersonic Mach numbers for which the wing leading edges remain swept behind the mark cone emanating from the wing apex. Variations of the sidewash with longitudinal distance in the vertical plane of symmetry are presented in graphical form. An approximate expression for the sidewash has been developed by means of an approach using a horseshoe-vortex approximate-lifting-line theory" (p. 455).
Date: October 21, 1955
Creator: Bobbitt, Percy J.
Item Type: Refine your search to only Report
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