On the plane potential flow past a symmetrical lattice of arbitrary airfoils (open access)

On the plane potential flow past a symmetrical lattice of arbitrary airfoils

Report presenting a theoretical investigation of the two-dimensional, incompressible potential flow past a symmetrical lattice of airfoils of arbitrary shape. Expressions are given for evaluation of the velocity and pressure distribution at the airfoil boundary.
Date: January 1944
Creator: Garrick, I. E.
System: The UNT Digital Library
Critical combinations of shear and transverse direct stress for an infinitely long flat plate with edges elastically restrained against rotation (open access)

Critical combinations of shear and transverse direct stress for an infinitely long flat plate with edges elastically restrained against rotation

Report presenting an exact solution and a closely concurring approximate energy solution for the buckling of an infinitely long flat plate under combined shear and transverse direct stress with edges elastically restrained against rotation. An appreciable fraction of the critical stress in pure shear may be applied to the plate without any reduction in the transverse compressive stress necessary to produce buckling.
Date: January 1945
Creator: Batdorf, S. B. & Houbolt, John C.
System: The UNT Digital Library
Compressible potential flow with circulation about a circular cylinder (open access)

Compressible potential flow with circulation about a circular cylinder

Report presenting the potential function for flow, with circulation, of a compressible fluid about a circular cylinder, which is obtained in series form including terms of the order of M(exp 4) where M is the Mach number of the free stream. The equations are used to obtain pressure coefficient as a function of Mach number at a point on the surface of the cylinder for different values of circulation.
Date: January 1944
Creator: Heaslet, Max A.
System: The UNT Digital Library
Single-Cylinder Oil-Control Tests of Porous Chrome Plated Cylinder Barrels for Radial Air-Cooled Engines (open access)

Single-Cylinder Oil-Control Tests of Porous Chrome Plated Cylinder Barrels for Radial Air-Cooled Engines

Report presenting a series of single-cylinder engine tests run to determine a satisfactory method of reducing oil consumption in radial air-cooled engines with flat-face compression rings as standard parts and equipped with cylinder barrels salvaged by porous chrome plating. Testing was conducted using porous chrome-plated cylinders with straight and choke bores with standard flat-face compression rings.
Date: January 1946
Creator: Johnson, Robert L. & Swikert, Max
System: The UNT Digital Library
Wind Tunnel Investigation of Control-Surface Characteristics 11: Various Large Overhang and Internal-Type Aerodynamic Balances for a Straight- Contour Flap on the NACA 0015 Airfoil (open access)

Wind Tunnel Investigation of Control-Surface Characteristics 11: Various Large Overhang and Internal-Type Aerodynamic Balances for a Straight- Contour Flap on the NACA 0015 Airfoil

Report presenting force-test measurements in two-dimensional flow in the 4- by 6-foot vertical tunnel to determine the characteristics of several different shaped overhang-type aerodynamic balances applied to a straight-contour flap mounted on an NACA 0015 airfoil. The flap with blunt-nose overhang was overbalanced throughout certain ranges of flap deflection. Results regarding precision, lift, flap hinge moments, pitching moment, and drag are provided.
Date: January 1943
Creator: Sears, Richard I. & Hoggard, H. Page, Jr.
System: The UNT Digital Library
Wind Tunnel Investigation of Control Surface Characteristics: [Part] 12 - Various Cover-Plate Alinements on the NACA 0015 Airfoil With a 30 Percent Chord Flap and Large Sealed Internal Balance (open access)

Wind Tunnel Investigation of Control Surface Characteristics: [Part] 12 - Various Cover-Plate Alinements on the NACA 0015 Airfoil With a 30 Percent Chord Flap and Large Sealed Internal Balance

Report presenting force-test measurements in two-dimensional flow made in the 4- by 6-foot vertical tunnel to determine the aerodynamic effects of changing the alignment of the cover plates on a sealed internally balanced flap. Manufacturing imperfections in the alignment of the cover plates with the airfoil contour may have serious effects on the resultant hinge moment of a flap with a sealed internal balance. Results regarding lift, flap hinge moments, pitching moment, and drag are provided.
Date: January 1943
Creator: Hoggard, H. Page, Jr.
System: The UNT Digital Library
Theory and preliminary flight tests of an all-movable vertical tail surface (open access)

Theory and preliminary flight tests of an all-movable vertical tail surface

Report presenting flight testing of an improved type of all-movable tail surface. The particular arrangement tested provides control-free stability and a stable variation of the control forces during maneuvers. Results regarding rudder effectiveness, directional stability, rudder-free lateral motion, and rudder-free turns are provided.
Date: January 1943
Creator: Jones, Robert T. & Kleckner, Harold F.
System: The UNT Digital Library
Aerodynamic characteristics and flap loads of perforated double split flaps on a rectangular NACA 23012 airfoil (open access)

Aerodynamic characteristics and flap loads of perforated double split flaps on a rectangular NACA 23012 airfoil

From Introduction: "The results of the load tests and some additional aerodynamic characteristics of perforated double split flaps on a rectangular NACA 23012 airfoil are given in the present report."
Date: January 1943
Creator: Turner, Thomas R.
System: The UNT Digital Library
Wind-tunnel tests of hinge-moment characteristics of spring-tab ailerons (open access)

Wind-tunnel tests of hinge-moment characteristics of spring-tab ailerons

Report presenting testing in the stability tunnel of two types of spring tab used as balances on a partial-span plain aileron. The tabs were connected to a spring located in the control system so that tab deflection was dependent on the control force.
Date: January 1944
Creator: Imlay, Frederick H. & Bird, J. D.
System: The UNT Digital Library
Wind-Tunnel Investigation of a Plain Aileron with Various Trailing-Edge Modifications on a Tapered Wing 3: Ailerons with Simple and Spring-Linked Balancing Tabs (open access)

Wind-Tunnel Investigation of a Plain Aileron with Various Trailing-Edge Modifications on a Tapered Wing 3: Ailerons with Simple and Spring-Linked Balancing Tabs

Aerodynamics data are obtained for the design of linked balancing tabs and effect of varied tab span and location to produce suitable lateral control characteristics with reasonable stick pressures for high-speed aircraft. Simple and spring-linked balancing tabs may considerably reduce control pressures if aileron system is designed for low maximum aileron deflection. Spring-linked tabs also decrease variation of stick pressure with speed and impart better controlllability at low speeds.
Date: January 1943
Creator: Purser, Paul E. & Rogallo, F. M.
System: The UNT Digital Library
An investigation of aircraft heaters 15: the emissivity of several materials (open access)

An investigation of aircraft heaters 15: the emissivity of several materials

Report presenting a determination of the mean effective emissivity as a function of temperature for the surfaces of several metals and insulating materials. A description and discussion of the measuring technique is presented. The results are plotted on a variety of graphs.
Date: January 1944
Creator: Boelter, L. M. K.; Bromberg, R. & Gier, J. T.
System: The UNT Digital Library
The effect of high loading on landing technique and distance, with experimental data for the B-26 airplane (open access)

The effect of high loading on landing technique and distance, with experimental data for the B-26 airplane

Report presenting an analysis of the effect of wing loading of the landing flare, which indicated that it had an important effect on landing technique and distance. Results regarding the approach and flare path and ground run are provided.
Date: January 1945
Creator: O'Sullivan, William J., Jr.
System: The UNT Digital Library
Investigation of Drag and Pressure Distribution of Windshields at High Speeds (open access)

Investigation of Drag and Pressure Distribution of Windshields at High Speeds

Report presenting tests in the 8-foot high-speed wind tunnel to determine the loads and the load distributions at high speeds for a number of windshields of the cockpit-canopy type. Ten windshields of various designs similar to those in general use were included in these tests. Results regarding drag, loads, and design considerations are provided.
Date: January 1942
Creator: Delano, James B. & Wright, Ray H.
System: The UNT Digital Library
A Theoretical Investigation of the Rolling Oscillations of an Airplane With Ailerons Free (open access)

A Theoretical Investigation of the Rolling Oscillations of an Airplane With Ailerons Free

Report discusses an analysis of the stability of an airplane with ailerons free, with particular attention to the motions when the ailerons have a tendency to float against the wind. Information about the aerodynamic balance of the plane and oscillations that may be encountered are included. The effects of friction in the control system is also explored.
Date: January 1944
Creator: Cohen, Doris
System: The UNT Digital Library
An empirical formula for the critical shear stress of curved sheets (open access)

An empirical formula for the critical shear stress of curved sheets

Report presenting tests to determine the critical shear stress of curved sheets. The empirical formula derived from the tests is applicable to panels with a ratio of radius to thickness of 300 or greater, a central angle of 1 radian or less, and a ratio of arc length to axial length not greater than 1.
Date: January 1945
Creator: Kuhn, Paul & Levin, L. Ross
System: The UNT Digital Library
The significance of the time concept in engine detonation (open access)

The significance of the time concept in engine detonation

Report presenting an experimental technique developed by means of which the variables affecting the time element in the detonation process in a spark-ignition engine can be controlled and approximately measured. Results indicated that higher maximum permissible pressures can be used if the rate of compression of the end gas is increased. Suggestions for future study are provided.
Date: January 1943
Creator: Leary, W. A. & Taylor, E. S.
System: The UNT Digital Library
An experimental survey of flow across banks of elliptical and pointed tubes (open access)

An experimental survey of flow across banks of elliptical and pointed tubes

Report presenting an experimental survey of the details of the flow of fluids across banks of streamline tubes as a continuation of previous work. Information that clarifies the picture of flow has been obtained by surveys of total, dynamic, and static pressure, and hot-wire cooling surveys of the unheated tubes.
Date: January 1943
Creator: Joyner, Upshur T. & Palmer, Carl B.
System: The UNT Digital Library
Single-Cylinder Engine Tests of Porous Chrome-Plated Cylinder Barrels With Special Bore Coatings for Radial Air-Cooled Engines (open access)

Single-Cylinder Engine Tests of Porous Chrome-Plated Cylinder Barrels With Special Bore Coatings for Radial Air-Cooled Engines

Report discussing a series of single-cylinder engine tests to determine the effect of special surface coatings in porous chrome-plated cylinder barrels on oil consumption and ring wear. The coating materials were selected for their bearing and lubrication properties and on their applicability to processing. The surface coatings tested were lead overplates, silver overplates, and colloidal graphite base paint.
Date: January 1946
Creator: Johnson, Robert L. & Anderson, Roy I.
System: The UNT Digital Library
Comparison of various methods for computing drag from wake surveys (open access)

Comparison of various methods for computing drag from wake surveys

"The various equations for computing profile drag by the momentum method are examined, and the errors arising from complete or partial neglect of compressibility effects in the Jones equation and the Bicknell equation are evaluated. The integrating method of Silverstein and Katzoff is shown to be accurate over a wide range of Mach number and wake shapes" (p. 1).
Date: January 1943
Creator: Davis, Wallace F.
System: The UNT Digital Library
Experimental Determination of the Effect of Negative Dihedral on Lateral Stability and Control Characteristics at High Lift Coefficients (open access)

Experimental Determination of the Effect of Negative Dihedral on Lateral Stability and Control Characteristics at High Lift Coefficients

Report presenting the effects of negative dihedral on lateral stability and control characteristics at high lift coefficients determined by flight tests with a model. As the effective dihedral was decreased, the model became increasingly difficult to fly. Results regarding the effect of directional stability and lift coefficient on flight behavior are also provided.
Date: January 1946
Creator: McKinney, Marion O., Jr.
System: The UNT Digital Library
Comparison of an approximate and an exact method of shear-lag analysis (open access)

Comparison of an approximate and an exact method of shear-lag analysis

Report presenting comparisons between the approximate substitute single-stringer method of shear-lag analysis and the exact solutions, which indicate that for beams of practical proportions the approximate method yields a value for the maximum root stress that exceeds the value obtained by use of the exact solution by less than 10 percent.
Date: January 1944
Creator: Duberg, John E.
System: The UNT Digital Library
Shear-Lag Tests of Two Box Beams With Corrugated Covers Loaded to Failure (open access)

Shear-Lag Tests of Two Box Beams With Corrugated Covers Loaded to Failure

"Strain measurements were made on the compression side of two box beams with corrugated aluminum-alloy covers loaded to failure. Angles formed from sheet were used for corner flanges in beam 1; whereas extruded angles were used in beam 2. Failure in each beam occurred in the corner angle at a stress that was above the compressive yield stress for the material" (p. 1).
Date: January 1944
Creator: Chiarito, Patrick T.
System: The UNT Digital Library
Additional design charts relating to the stalling of tapered wings (open access)

Additional design charts relating to the stalling of tapered wings

From Introduction: "The present report, therefore, may be considered a supplement to reference 1. The combined scope of the stall charts of reference 1, designated A, and of the present work, designated B, is summarized in the following table: For the wing with root thickness ratio to 18 was also investigated.
Date: January 1943
Creator: Harmon, Sidney M.
System: The UNT Digital Library
Flight Investigation of NACA D(Sub S) Cowlings on the XP-42 Airplane 1: High-Inlet-Velocity Cowling with Propeller Cuffs Tested in High-Speed Level Flight (open access)

Flight Investigation of NACA D(Sub S) Cowlings on the XP-42 Airplane 1: High-Inlet-Velocity Cowling with Propeller Cuffs Tested in High-Speed Level Flight

Report presenting results from a series of flight tests of the maximum speed and cooling characteristics in full-throttle level flight of the XP-42 airplane equipped with a short-nose high-inlet velocity cowling. The results of the tests indicated a maximum speed of 336 miles per hour at 960 horsepower at 25,000 feet. Results regarding maximum speed and pressure and temperatures are provided.
Date: January 1943
Creator: Bailey, F. J., Jr.
System: The UNT Digital Library