Compressive Strength of Flat Panels With Z-Section Stiffeners (open access)

Compressive Strength of Flat Panels With Z-Section Stiffeners

Report presenting compression testing on several series of flat panels with Z-section stiffeners with varying relative dimensions. The data presented show the effect of dimension ratio on the buckling stress for the sheet and on average stress at maximum load.
Date: February 1944
Creator: Rossman, Carl A.; Bartone, Leonard M. & Dobrowski, Charles V.
System: The UNT Digital Library
Determination of the Stability and Control Characteristics of a Tailless All-Wing Airplane Model with Sweepback in the Langley Free-Flight Tunnel (open access)

Determination of the Stability and Control Characteristics of a Tailless All-Wing Airplane Model with Sweepback in the Langley Free-Flight Tunnel

Force and flight tests were performance on an all-wing model with windmilling propellers. Tests were conducted with deflected and retracted flaps, with and without auxiliary vertical tail surfaces, and with different centers of gravity and trim coefficients. Results indicate serious reduction of stick-fixed longitudinal stability because of wing-tip stalling at high lift coefficient. Directional stability without vertical tail is undesirably low. Low effective dihedral should be maintained. Elevator and rudder control system is satisfactory.
Date: February 1945
Creator: Campbell, John P. & Seacord, Charles L., Jr.
System: The UNT Digital Library
Equilibrium Operating Performance of Axial-Flow Turbojet Engines by Means of Idealized Analysis (open access)

Equilibrium Operating Performance of Axial-Flow Turbojet Engines by Means of Idealized Analysis

"A method of predicting equilibrium operating performance of turbojet engines has been developed, with the assumption of simple model processes for the components. Results of the analysis are plotted in terms of dimensionless parameters comprising critical engine dimensions and over-all operating variables. This investigation was made of an engine in which the ratio of axial inlet-air velocity to compressor-tip velocity is constant, which approximates turbojet engines with axial-flow compressors" (p. 673).
Date: February 25, 1949
Creator: Sanders, John C. & Chapin, Edward C.
System: The UNT Digital Library
Wind-tunnel investigation of the effect of clipping the tips of triangular wings of different thickness, camber, and aspect ratio - transonic bumb method (open access)

Wind-tunnel investigation of the effect of clipping the tips of triangular wings of different thickness, camber, and aspect ratio - transonic bumb method

Report presenting an investigation on a transonic bump to determine the aerodynamic characteristics of a series of triangular wings. Four basic triangular-wing plan forms with different aspect ratios, taper ratios, and combinations of tip clipping were tested over a range of Mach and Reynolds numbers. Results regarding angle of attack, drag coefficient, pitching-moment coefficient with lift coefficient, and various curves are provided.
Date: February 3, 1954
Creator: Emerson, Horace F.
System: The UNT Digital Library
Theoretical Study of the Tunnel-Boundary Lift Interference Due to Slotted Walls in the Presence of the Trailing-Vortex System of a Lifting Model (open access)

Theoretical Study of the Tunnel-Boundary Lift Interference Due to Slotted Walls in the Presence of the Trailing-Vortex System of a Lifting Model

"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" (p. 361).
Date: February 3, 1953
Creator: Matthews, Clarence W.
System: The UNT Digital Library
Analysis of Turbulent Heat Transfer, Mass Transfer, and Friction in Smooth Tubes at High Prandtl and Schmidt Numbers (open access)

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

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.
System: The UNT Digital Library
Contributions on the Mechanics of Boundary-Layer Transition (open access)

Contributions on the Mechanics of Boundary-Layer Transition

"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.
System: The UNT Digital Library
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 (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

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 for infinite boundary-layer stability at this Mach number. The maximum heating corresponded to a temperature ratio of about 1.85. Included in the investigation was a study of the effects of surface irregularities and disturbances generated in the airstream on the ability of heat transfer to influence boundary-layer transition.
Date: February 16, 1953
Creator: Czarnecki, K. R. & Sinclair, Archibald R.
System: The UNT Digital Library
Friction, wear, and surface damage of metals as affected by solid surface films (open access)

Friction, wear, and surface damage of metals as affected by solid surface films

"As predicted by friction theory, experiments showed that friction and surface damage of metals can be reduced by solid surface films. The ability of materials to form surface films that prevent welding was a very important factor in wear of dry and boundary lubricated surfaces. Films of graphitic carbon on cast irons, NiO on nickel alloys, and FeO and Fe(sub 3)O(sub 4) on ferrous materials were found to be beneficial. Abrasive films such as Fe(sub 2)O(sub 3) or MoO(sub 3) were definitely detrimental. It appears that the importance of oxide films to friction and wear processes has not been fully appreciated" (p. 93).
Date: February 10, 1955
Creator: Bisson, Edmond E.; Johnson, Robert L.; Swikert, Max A. & Godfrey, Douglas
System: The UNT Digital Library
On the Kernel function of the integral equation relating lift and downwash distributions of oscillating wings in supersonic flow (open access)

On the Kernel function of the integral equation relating lift and downwash distributions of oscillating wings in supersonic flow

From Summary: "This report treats the Kernel function of the integral equation that relates a known or prescribed downwash distribution to an unknown lift distribution for harmonically oscillating wings in supersonic flow. The treatment is essentially an extension to supersonic flow of the treatment given in NACA report 1234 for subsonic flow. For the supersonic case the Kernel function is derived by use of a suitable form of acoustic doublet potential which employs a cutoff or Heaviside unit function. The Kernel functions are reduced to forms that can be accurately evaluated by considering the functions in two parts: a part in which the singularities are isolated and analytically expressed, and a nonsingular part which can be tabulated."
Date: February 15, 1955
Creator: Watkins, Charles E. & Berman, Julian H.
System: The UNT Digital Library
The near noise field of static jets and some model studies of devices for noise reduction (open access)

The near noise field of static jets and some model studies of devices for noise reduction

An experimental study is presented of the pressure fluctuations near jet exhaust streams made during unchoked operation of a turbojet engine and a 1-inch-diameter high-temperature model jet and during choked operation of various sizes of model jets with unheated air. The tests for unchoked operation indicate a random spectrum of rather narrow band width which varies in frequency content with axial position along the jet. Pressure surveys from the model tests along lines parallel to the 15 degree jet boundary indicate that the station of greatest pressure fluctuations is determined by the jet velocity and the radial distance, with a tendency of the maximum to shift downstream as either parameter is increased.
Date: February 19, 1954
Creator: Lassiter, Leslie W. & Hubbard, Harvey H.
System: The UNT Digital Library
Comparative Tests of the Strength and Tightness of Commercial Flush Rivets of One Type and NACA Flush Rivets in Machine-Countersunk and Counterpunched Joints (open access)

Comparative Tests of the Strength and Tightness of Commercial Flush Rivets of One Type and NACA Flush Rivets in Machine-Countersunk and Counterpunched Joints

Report discusses an investigation that was conducted to compare the strength and tightness of machine-countersunk flush-riveted joints assembled with NACA flush rivets and a type of commercial flush rivet. A comparison was also generated between the strength and tightness of counterpunched flush-riveted joints assembled with the same types of rivet. NACA's flush-riveted joints tended to be stronger and tighter than the commercial joints.
Date: February 1, 1944
Creator: Mandel, Merven W.
System: The UNT Digital Library
Determination of Rate, Area, and Distribution of Impingement of Waterdrops on Various Airfoils From Trajectories Obtained on the Differential Analyzer (open access)

Determination of Rate, Area, and Distribution of Impingement of Waterdrops on Various Airfoils From Trajectories Obtained on the Differential Analyzer

"The trajectories of waterdrops in air flowing over airfoils are determined for three airfoil - angle-of-attack combinations using the differential analyzer to solve the differential equations of motion of the waterdrops. From these trajectories the rate of water impingement, the area of impingement, and the distribution of impingement are determined as functions of two dimensionless moduli. Comparisons are made of the rate of water impingement on these airfoils and the rate of water impingement on cylinders" (p. 1).
Date: February 16, 1949
Creator: Guibert, A. G.; Janssen, E. & Robbins, W. M.
System: The UNT Digital Library
Rocket-Model Investigation of the Rolling Effectiveness of a Fighter-Type Wing-Control Configuration at Mach Numbers From (open access)

Rocket-Model Investigation of the Rolling Effectiveness of a Fighter-Type Wing-Control Configuration at Mach Numbers From

"An investigation of the rolling effectiveness of spoiler and aileron aerodynamic controls on a fighter-type airplane has been conducted at Mach numbers from 0.6 to 1.5 by the Langley Pilotless Aircraft Research Division by utilizing rocket-propelled test vehicles. No effects of mutual interference between the midspan spoiler and the outboard aileron were detectable. Above the speed of sound, the ailerons were relatively ineffective as compared with the spoiler because of wing twisting" (p. 1).
Date: February 25, 1952
Creator: Strass, H. Kurt & Marley, Edward T.
System: The UNT Digital Library
Additional Experiments With Flat-Top Wing- Body Combinations at High Supersonic Speeds (open access)

Additional Experiments With Flat-Top Wing- Body Combinations at High Supersonic Speeds

Memorandum presenting an experimental study of the effects of several variations in configuration geometry on the aerodynamic characteristics of flat-top wing-body combinations. Generally, the configurations consist of one half of a body of revolution mounted beneath a wing of essentially arrow plan form. Results regarding the effect of trailing-edge sweep, effect of the addition of auxiliary bodies, effect of tip-flap deflection, effect of dihedral, effect of leading-edge sweep, effect of fuselage fineness ratio, effect of fuselage profile shape, and static longitudinal stability characteristics are provided.
Date: February 19, 1957
Creator: Syvertson, Clarence A.; Wong, Thomas J. & Gloria, Hermilo R.
System: The UNT Digital Library
Dynamic Stability Investigation of Two Right Circular Cylinders in Axial Free Flight at Mach Numbers From 0.4 to 1.7 Fineness-Ratio- 2.56 Cylinder and Fineness-Ratio-4.0 Cylinder With Flared Afterbody (open access)

Dynamic Stability Investigation of Two Right Circular Cylinders in Axial Free Flight at Mach Numbers From 0.4 to 1.7 Fineness-Ratio- 2.56 Cylinder and Fineness-Ratio-4.0 Cylinder With Flared Afterbody

Memorandum presenting two right circular cylinders tested in axial free flight over a Mach number range of 0.4 to 1.7 by using the rocket-boosted-model technique. Results regarding time history, basic data cross plots, center of pressure, and drag are provided.
Date: February 28, 1957
Creator: McFall, John C., Jr.
System: The UNT Digital Library
Theoretical Performance of Liquid Hydrogen and Liquid Fluorine as a Rocket Propellant (open access)

Theoretical Performance of Liquid Hydrogen and Liquid Fluorine as a Rocket Propellant

Report of theoretical values of performance parameters for liquid hydrogen and flourine as a rocket propellant for a wide range of fuel-oxidant and expansion ratios. Parameters computed include specific impulse, combustion-chamber temperature, nozzle-exit temperature, equilibrium composition, mean molecular weight, characteristic velocity, coefficient of thrust, ratio of nozzle-exit area to throat area, specific heat at constant pressure, coefficient of viscosity, and coefficient of thermal conductivity.
Date: February 6, 1953
Creator: Gordon, Sanford & Huff, Vearl N.
System: The UNT Digital Library
Cooling Characteristics of an Experimental Tail-Pipe Burner With an Annular Cooling-Air Passage (open access)

Cooling Characteristics of an Experimental Tail-Pipe Burner With an Annular Cooling-Air Passage

Memorandum presenting the tail-pipe fuel ratio, mass flow of combustion gas, and radial fuel flow distribution on cooling requirements of tail-pipe burner with annular cooling-air passage.
Date: February 26, 1952
Creator: Koffel, William K. & Kaufman, Harold R.
System: The UNT Digital Library
Transonic Aerodynamic and Trim Characteristics of a Multi-Engine Delta-Wing Airplane Model (open access)

Transonic Aerodynamic and Trim Characteristics of a Multi-Engine Delta-Wing Airplane Model

Memorandum presenting an investigation of three models of a delta-wing airplane designed for a long-range subsonic cruise and a supersonic dash. Results regarding the aerodynamic characteristics of the models and effect of elevon deflection on aerodynamic characteristics of the four-engine model are provided.
Date: February 17, 1956
Creator: Swihart, John M. & Foss, Willard E., Jr.
System: The UNT Digital Library
Some Interference Effects That Influence Vertical-Tail Loads at Supersonic Speeds (open access)

Some Interference Effects That Influence Vertical-Tail Loads at Supersonic Speeds

Memorandum presenting three types of aerodynamic interference originating from forward components of airplanes, which are shown to contribute to decreased vertical-tail effectiveness. The vorticity originating from a slender fuselage ahead of the wing resulted in a marked reduction in vertical-tail effectiveness with angle of attack for one model.
Date: February 17, 1956
Creator: Edwards, S. Sherman
System: The UNT Digital Library
The Influence of Surface Injection on Heat-Transfer and Skin Friction Associated With the High-Speed Turbulent Boundary Layer (open access)

The Influence of Surface Injection on Heat-Transfer and Skin Friction Associated With the High-Speed Turbulent Boundary Layer

Memorandum presenting a correlation of analyses of the effect of distributed surface injection on the heat transfer and skin friction associated with the turbulent boundary layer at high speeds to eliminate the effects of Mach and Reynolds number. Data for heat transfer and skin friction at three Mach numbers are compared with the analyses and the agreement is good.
Date: February 20, 1956
Creator: Rubesin, Morris W.
System: The UNT Digital Library
Force, moment, and pressure characteristics of several annular nose inlets at Mach number 3.85 (open access)

Force, moment, and pressure characteristics of several annular nose inlets at Mach number 3.85

Report presenting an investigation to evaluate the overall performance characteristics of several annular nose inlets in the supersonic wind tunnel at a Mach number of 3.85. The four experimental configurations investigated consisted of a one-cone, a one-cone with low angle cowl, a two-cone, and an isentropic inlet. Results regarding the internal-flow performance, force measurements at zero angle of attack, overall performance comparison at zero angle of attack, and angle-of-attack force measurement are provided.
Date: February 3, 1954
Creator: Connors, James F. & Woollett, Richard R.
System: The UNT Digital Library
Investigation of Aerodynamic Characteristics in Pitch and Sideslip of a 45 Degree Sweptback-Wing Airplane Model With Various Vertical Locations of Wing and Horizontal Tail: Static Longitudinal Stability and Control, M = 2.01 (open access)

Investigation of Aerodynamic Characteristics in Pitch and Sideslip of a 45 Degree Sweptback-Wing Airplane Model With Various Vertical Locations of Wing and Horizontal Tail: Static Longitudinal Stability and Control, M = 2.01

Memorandum presenting an investigation in the 4- by 4-foot supersonic pressure tunnel to determine the effects of various vertical locations of the wing and horizontal tail on the aerodynamic characteristics in pitch and of a supersonic airplane configuration at Mach number 2.01. The model was equipped with a wing and horizontal tail, each having a 45 degree sweep and an aspect ratio of 4. The configurations investigated included a high-wing, a mid-wing, and a low-wing arrangement, each with four different horizontal tail locations varying from a position 0.208 semispan below to 0.556 semispan above the body center line.
Date: February 21, 1956
Creator: Spearman, M. Leroy & Driver, Cornelius
System: The UNT Digital Library
The belt method for measuring pressure distribution (open access)

The belt method for measuring pressure distribution

"The measurement of pressure distribution may be accomplished rapidly for any number of locations deemed necessary in model or full-scale investigations by use of the 'belt' method. Reasonable accuracy may be obtained by careful use of this method" (p. 1).
Date: February 1943
Creator: Corson, Blake W., Jr.
System: The UNT Digital Library