83 Matching Results

Results open in a new window/tab.

Experimental and theoretical studies of area suction for the control of the laminar boundary layer on an NACA 64A010 airfoil (open access)

Experimental and theoretical studies of area suction for the control of the laminar boundary layer on an NACA 64A010 airfoil

From Summary: "A low-turbulence wind-tunnel investigation was made of an NACA 64A010 airfoil having a porous surface to determine the reduction in section total-drag coefficient that might be obtained at large Reynolds numbers by the use of suction to produce continuous inflow through the surface of the airfoil (area suction). In addition to the experimental investigation, a related theoretical analysis was made to provide a basis of comparison for the test results."
Date: March 30, 1951
Creator: Braslow, Albert L.; Burrows, Dale L.; Tetervin, Neal & Visconti, Fioravante
System: The UNT Digital Library
On flow of electrically conducting fluids over a flat plate in the presence of a transverse magnetic field (open access)

On flow of electrically conducting fluids over a flat plate in the presence of a transverse magnetic field

The use of a magnetic field to control the motion of electrically conducting fluids is studied. The incompressible boundary-layer solutions are found for flow over a flat plate when the magnetic field is fixed relative to the plate or to the fluid. The equations are integrated numerically for the effect of the transverse magnetic field on the velocity and temperature profiles, and hence, the skin friction and rate of heat transfer. It is concluded that the skin friction and the heat-transfer rate are reduced when the transverse magnetic field is fixed relative to the plate and increased when fixed relative to the fluid. The total drag is increased in all of the areas.
Date: March 13, 1957
Creator: Rossow, Vernon J.
System: The UNT Digital Library
A variational theorem for creep with applications to plates and columns (open access)

A variational theorem for creep with applications to plates and columns

A variational theorem is presented for a body undergoing creep. Solutions to problems of the creep behavior of plates, columns, beams, and shells can be obtained by means of the direct methods of the calculus of variations in conjunction with the stated theorem. The application of the theorem is illustrated for plates and columns by the solution of two sample problems.
Date: March 5, 1957
Creator: Sanders, J. Lyell, Jr.; McComb, Harvey G., Jr. & Schlechte, Floyd R.
System: The UNT Digital Library
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 (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

"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 stations within 45 degrees of the stagnation point the heat-transfer coefficients could be correlated by a single relation between local Stanton number and local Reynolds number" (p. 1001).
Date: March 21, 1956
Creator: Crawford, Davis H. & McCauley, William D.
System: The UNT Digital Library
Comparison of several methods for obtaining the time response of linear systems to either a unit impulse or arbitrary input from frequency-response data (open access)

Comparison of several methods for obtaining the time response of linear systems to either a unit impulse or arbitrary input from frequency-response data

From Summary: "Several methods of obtaining the time response of Linear systems to either a unit impulse or an arbitrary input from frequency-response data are described and compared. Comparisons indicate that all the methods give good accuracy when applied to a second-order system; the main difference is the required computing time. The methods generally classified as inverse Laplace transform methods were found to be most effective in determining the response to a unit impulse from frequency-response data of higher order systems. Some discussion and examples are given of the use of such methods as flight-data-analysis techniques in predicting loads and motions of a flexible aircraft on the basis of simple calculations when the aircraft frequency response is known."
Date: March 16, 1956
Creator: Donegan, James J. & Huss, Carl R.
System: The UNT Digital Library
Pressure-sensitive system for gas-temperature control (open access)

Pressure-sensitive system for gas-temperature control

From Summary: "A thermodynamic relation is derived and simplified for use as a temperature-limiting control equation involving measurement of gas temperature before combustion and gas pressures before and after combustion. For critical flow in the turbine nozzles of gas-turbine engines, the control equation is further simplified to require only measurements upstream of the burner. Hypothetical control systems are discussed to illustrate application of the control equations."
Date: March 4, 1948
Creator: Cesaro, Richard S. & Matz, Norman
System: The UNT Digital Library
Analysis of spanwise temperature distribution in three types of air-cooled turbine blade (open access)

Analysis of spanwise temperature distribution in three types of air-cooled turbine blade

From Summary: An approximate method for determining the allowable stress-limited blade-temperature distribution is included, with brief accounts of a method for determining the maximum allowable effective gas temperatures and the cooling-air requirements. Numerical examples that illustrate the use of the various temperature-distribution equations and of the nondimensional charts are also included.
Date: March 1, 1950
Creator: Livingood, John N. B. & Brown, W. Byron
System: The UNT Digital Library
Structural Response to Discrete and Continuous Gusts of an Airplane Having Wing Bending Flexibility and a Correlation of Calculated and Flight Results (open access)

Structural Response to Discrete and Continuous Gusts of an Airplane Having Wing Bending Flexibility and a Correlation of Calculated and Flight Results

"An analysis is made of the structural response to gusts of an airplane having the degrees of freedom of vertical motion and wing bending flexibility and basic parameters are established. A convenient and accurate numerical solution of the response equations is developed for the case of discrete-gust encounter, an exact solution is made for the simpler case of continuous-sinusoidal-gust encounter, and the procedure is outlined for treating the more realistic condition of continuous random atmospheric turbulence, based on the methods of generalized harmonic analysis. Correlation studies between flight and calculated results are then given to evaluate the influence of wing bending flexibility on the structural response to gusts of two twin-engine transports and one four-engine bomber" (p. 1).
Date: March 4, 1954
Creator: Houbolt, John C. & Kordes, Eldon E.
System: The UNT Digital Library
Initial results of instrument-flying trials conducted in a single-rotor helicopter (open access)

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

"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.
System: The UNT Digital Library
A study of the characteristics of human-pilot control response to simulated aircraft lateral motions (open access)

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

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.
System: The UNT Digital Library
Summary of Airfoil Data (open access)

Summary of Airfoil Data

From Summary: "Recent airfoil data for both flight and wind-tunnel tests have been collected and correlated insofar as possible. The flight data consist largely of drag measurements made by the wake-survey method. Most of the data on airfoil section characteristics were obtained in the Langley two-dimensional low-turbulence pressure tunnel. Detail data necessary for the application of NACA 6-serles airfoils to wing design are presented in supplementary figures, together with recent data for the NACA 24-, 44-, and 230-series airfoils."
Date: March 1945
Creator: Stivers, Louis S.; Abbott, Ira H. & von Doenhoff, Albert E.
System: The UNT Digital Library