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Revision of the American Flying Squirrels (open access)

Revision of the American Flying Squirrels

Habits, voice, nests, breeding, food, economic status, pelage and molt, and descriptions of species and subspecies of the American flying squirrels.
Date: June 13, 1918
Creator: Howell, Arthur H.
Object Type: Report
System: The UNT Digital Library
Performance of B. M. W. 185-horsepower airplane engine (open access)

Performance of B. M. W. 185-horsepower airplane engine

Report discusses the results of testing on a B.M.W. engine in an altitude chamber where temperature and pressure can be controlled to simulate flight at various altitudes. Results for various engine speeds, altitudes, and propeller speeds are provided.
Date: April 13, 1922
Creator: Sparrow, Stanwood Willston
Object Type: Report
System: The UNT Digital Library
Testing of Fire-Clay Brick with Special Reference to their Use in Coal-Fired Boiler Settings (open access)

Testing of Fire-Clay Brick with Special Reference to their Use in Coal-Fired Boiler Settings

Technical paper issued by the Bureau of Standards over studies conducted on fire-clay bricks. The results of the studies are discussed. This paper includes tables, and illustrations.
Date: February 13, 1925
Creator: Geller, R. F.
Object Type: Report
System: The UNT Digital Library
Measurements on the Thermal Expansion of Fused Silica (open access)

Measurements on the Thermal Expansion of Fused Silica

Scientific paper issued by the Bureau of Standards over thermal expansion of fused silica. As stated in the abstract, "this paper gives the results of an investigation on the thermal expansion of transparent and nontransparent fused silica for various temperature ranges between -125 and +1,000 degrees Celsius. A detailed description of the apparatus and the methods used in this research and a summary of available data obtained by previous observers on the thermal expansion of fused silica are given" (p. 1). This paper includes tables, photographs, and illustrations.
Date: April 13, 1926
Creator: Souder, Wilmer H. & Hidnert, Peter
Object Type: Report
System: The UNT Digital Library
Full-Scale Wind-Tunnel Tests of a Series of Metal Propellers on a VE-7 Airplane (open access)

Full-Scale Wind-Tunnel Tests of a Series of Metal Propellers on a VE-7 Airplane

"An adjustable blade metal propeller was tested at five different angle settings, forming a series varying in pitch. The propeller was mounted on a VE-7 airplane in the twenty-foot propeller research tunnel of the National Advisory Committee for Aeronautics. The efficiencies were found to be from 4 to 7 per cent higher than those of standard wood propellers operating under the same conditions. The results are given in convenient form for use in selecting propellers for aircraft" (p. 521).
Date: July 13, 1928
Creator: Weick, Fred E.
Object Type: Report
System: The UNT Digital Library
The Effect of Supercharger Capacity on Engine and Airplane Performance (open access)

The Effect of Supercharger Capacity on Engine and Airplane Performance

This report presents the results of an investigation to determine the effect of different supercharger capacities on the performance of an airplane and its engine . The tests were conducted on a DH4-M2 airplane powered with a Liberty 12 engine. In this investigation four supercharger capacities, obtained by driving a roots type supercharger at 1.615, 1.957, 2.4, and 3 time engine speed, were used to maintain sea-level pressure at the carburetor to altitudes of 7,000, 11,500, 17,000, and 22,000 feet, respectively. The performance of the airplane in climb and in level flight was determined for each of the four supercharger drive ratios and for the unsupercharged condition.
Date: March 13, 1929
Creator: Schey, O. W. & Gove, W. D.
Object Type: Report
System: The UNT Digital Library
Applied Potential Corrosion of Aluminum and 18-8 Stainless Steel Alloys (open access)

Applied Potential Corrosion of Aluminum and 18-8 Stainless Steel Alloys

Introduction: In anticipation of the design of equipment for heat transfer tests, a series of short exposure corrosion tests was initiated in an effort to determine the order of magnitude of the corrosion involved. Information was required on the effect on corrosion rates of applying a potential between two concentric tubes, the annulus between them containing condensate water.
Date: March 13, 1930
Creator: Sanborn, Kenneth L.
Object Type: Report
System: The UNT Digital Library
The Comparative Performance of Superchargers (open access)

The Comparative Performance of Superchargers

"This report presents a comparison of superchargers on the basis of the power required to compress the air at a definite rate, and on the basis of the net engine power developed at altitudes from 0 to 40,000 feet. The investigation included geared centrifugal, turbine-driven centrifugal, roots, and vane-type superchargers. It also includes a brief discussion of the mechanical limitations of each supercharger and explains how the method of control affects the power requirements" (p. 425).
Date: January 13, 1931
Creator: Schey, Oscar W.
Object Type: Report
System: The UNT Digital Library
The Elimination of Fire Hazard Due to Back Fires (open access)

The Elimination of Fire Hazard Due to Back Fires

"A critical study was made of the operation of a type of back-fire arrester used to reduce the fire hazard of aircraft engines. A flame arrester consisting of a pack or plug of alternate flat and corrugated plates of thin metal was installed in the intake pipe of a gasoline engines; an auxiliary spark plug inserted in the intake manifold permitted the production of artificial back fires at will. It was found possible to design a plug which prevented all back fires from reaching the carburetor" (p. 211).
Date: October 13, 1931
Creator: Theodorsen, Theodore & Freeman, Ira M.
Object Type: Report
System: The UNT Digital Library
Experiments on the distribution of fuel in fuel sprays (open access)

Experiments on the distribution of fuel in fuel sprays

The distribution of fuel in sprays for compression-ignition engines was investigated by taking high-speed spark photographs of fuel sprays reproduced under a wide variety of conditions, and also by injecting them against pieces of plasticine. A photographic study was made of sprays injected into evacuated chambers, into the atmosphere, into compressed air, and into transparent liquids. Pairs of identical sprays were injected counter to each other and their behavior analyzed. Small high velocity air jets were directed normally to the axes of fuel sprays, with the result that the envelope of spray which usually obscures the core was blown aside, leaving the core exposed on one side. The results showed that the distribution of the fuel within the sprays was very uneven.
Date: February 13, 1932
Creator: Lee, Dana W.
Object Type: Report
System: The UNT Digital Library
Wind-Tunnel Research Comparing Lateral Control Devices, Particularly at High Angles of Attack 5: Spoilers and Ailerons on Rectangular Wings (open access)

Wind-Tunnel Research Comparing Lateral Control Devices, Particularly at High Angles of Attack 5: Spoilers and Ailerons on Rectangular Wings

"This report covers the fifth of a series of systematic investigations in which lateral control devices are compared with particular reference to their effectiveness at high angles of attack. The present report deals with tests of spoilers and ordinary ailerons on rectangular Clark Y wing models. In an effort to obtain satisfactory control throughout the entire angle-of-attack range that can be maintained in flight, various spoilers were tested in combination with two sizes of previously tested ordinary ailerons - one of average proportions and the other short and wide. In addition, one large spoiler was tested alone" (p. 719).
Date: June 13, 1932
Creator: Weick, Fred E. & Shortal, Joseph A.
Object Type: Report
System: The UNT Digital Library
The N.A.C.A. Full-Scale Wind Tunnel (open access)

The N.A.C.A. Full-Scale Wind Tunnel

This report gives a complete description of the full-scale wind tunnel of the National Advisory Committee for Aeronautics.
Date: March 13, 1933
Creator: DeFrance, Smith J.
Object Type: Report
System: The UNT Digital Library
Performance of a fuel-injection spark-ignition engine using a hydrogenated safety fuel (open access)

Performance of a fuel-injection spark-ignition engine using a hydrogenated safety fuel

This report presents the performance of a single-cylinder test engine using a hydrogenated safety fuel. The safety fuel has a flash point of 125 degrees f. (Cleveland open-dup method), which is high enough to remove most of the fire hazard, and an octane number of 95, which permits higher compression ratios to be used than are permissible with most undoped gasolines.
Date: June 13, 1933
Creator: Schey, Oscar W. & Young, Alfred W.
Object Type: Report
System: The UNT Digital Library
Effect of Viscosity on Fuel Leakage Between Lapped Plungers and Sleeves and on the Discharge From a Pump-Injection System (open access)

Effect of Viscosity on Fuel Leakage Between Lapped Plungers and Sleeves and on the Discharge From a Pump-Injection System

"Test data and analysis show that the rate of fuel leakage between a lapped plunger and sleeve varies directly with the density of the fuel, the diameter of the plunger, the pressure producing the leakage, and the cube of the mean clearance between the plunger and sleeve. The rate varies inversely as the length of the lapped fit and the viscosity of the fuel. With a mean clearance between the plunger and sleeve of 0.0001 inch the leakage amounts to approximately 0.2 percent of the fuel injected with gasoline and as low as 0.01 percent with diesel fuel oils" (p. 63).
Date: December 13, 1933
Creator: Rothrock, A. M. & Marsh, E. T.
Object Type: Report
System: The UNT Digital Library
Wing-Fuselage Interference, Tail Buffeting, and Air Flow About the Tail of a Low-Wing Monoplane (open access)

Wing-Fuselage Interference, Tail Buffeting, and Air Flow About the Tail of a Low-Wing Monoplane

"This report presents the results of wind tunnel tests on a Mcdonnell Douglas airplane to determine the wing-fuselage interference of a low-wing monoplane. The tests included a study of tail buffeting and the air flow in the region of the tail. The airplane was tested with and without the propeller slipstream, both in the original condition and with several devices designed to reduce or eliminate tail buffeting. The devices used were wing-fuselage fillets, a NACA cowling, reflexed trailing edge of the wing, and stub auxiliary airfoils" (p. 143).
Date: December 13, 1933
Creator: White, James A. & Hood, Manley J.
Object Type: Report
System: The UNT Digital Library
An Analysis of Longitudinal Stability in Power-Off Flight With Charts for Use in Design (open access)

An Analysis of Longitudinal Stability in Power-Off Flight With Charts for Use in Design

"This report presents a discussion of longitudinal stability in gliding flight together with a series of charts with which the stability characteristics of any airplane may be readily estimated. The relationships governing stability characteristics are derived from equations of equilibrium referred to moving axes that are tangent and perpendicular to the instantaneous flight path. It is shown that instability of the motion can arise only through an increase of linear and angular momentum in the system during one complete cycle" (p. 289).
Date: December 13, 1934
Creator: Zimmerman, Charles H.
Object Type: Report
System: The UNT Digital Library
Bibliography of Temperature Measurement: July 1960 to December 1962 (open access)

Bibliography of Temperature Measurement: July 1960 to December 1962

Report presenting 700 additional references to the field of temperature measurement as a supplement to NBS Monograph 27, "Bibliography of Temperature Measurement, January 1953 to June 1960" issued April 6, 1961. These references were collected from two general sources: Scientific and technical literature and government reports. The period covered is from July 1960 to December 1962 with some earlier references which were found later. The arrangement of material is the same as in Monograph 27.
Date: September 13, 1936
Creator: Halpern, Carl
Object Type: Report
System: The UNT Digital Library
Wind-Tunnel Investigation of Spoiler, Deflector, and Slot Lateral-Control Devices on Wings With Full-Span Split and Slotted Flaps (open access)

Wind-Tunnel Investigation of Spoiler, Deflector, and Slot Lateral-Control Devices on Wings With Full-Span Split and Slotted Flaps

Report presents the results of an extensive investigation made in the NACA 7 by 10-foot wind tunnel of spoiler, deflector, and slot types of lateral-control device on wings with full-span split and slotted flaps. The static rolling and yawing moments were determined for all the devices tested, and the static hinge moments and the time response were determined for a few devices of each type.
Date: August 13, 1940
Creator: Wenzinger, Carl J. & Rogallo, Francis M.
Object Type: Report
System: The UNT Digital Library
Restraint provided a flat rectangular plate by a sturdy stiffener along an edge of the plate (open access)

Restraint provided a flat rectangular plate by a sturdy stiffener along an edge of the plate

From Summary: "A sturdy stiffener is defined as a stiffener of such proportions that it does not suffer cross-sectional distortion when moments are applied to some part of the cross section. When such a stiffener is attached to one edge of a plate, it will resist rotation of that edge of the plate by means of its torsional properties. A formula is given for the restraint coefficient provided the plate by such a stiffener. This coefficient is required for the calculation of the critical compressive stress of the plate."
Date: March 13, 1941
Creator: Lundquist, Eugene E. & Stowell, Elbridge Z.
Object Type: Report
System: The UNT Digital Library
Wind-Tunnel Tests of Four- and Six-Blade Single- and Dual-Rotating Tractor Propellers (open access)

Wind-Tunnel Tests of Four- and Six-Blade Single- and Dual-Rotating Tractor Propellers

"Test of 10-foot diameter, four and six blade single-rotating and dual-rotating propellers were conducted in the NACA propeller-research tunnel. The propellers were mounted at the front end of a streamline body incorporating spinners to house the hub portions. The effect of a symmetrical wing mounted in the slipstream ranged from 20 degrees to 65 degrees setting corresponds to airplane speeds greater than 500 miles per hour. The results indicate that dual-rotating propellers were from 0 to 6 percent more efficient than single-rotating ones; but, when the propellers operated in the presence of a wing, the gain was reduced by about one-half" (p. 319).
Date: July 13, 1942
Creator: Biermann, David & Hartman, Edwin P.
Object Type: Report
System: The UNT Digital Library
Optimum Design of Catalytic Towers (open access)

Optimum Design of Catalytic Towers

Abstract: "This paper gives an arithmetic method of computing the number of sections required in a catalytic tower to produce a given enrichment. It also tells how to calculate the enrichment of a tower with a given number of sections. The problem of the most economical design of catalytic towers is solved. Methods are given for determining the temperature, the efficiencies of catalyst beds and strippers, the relative production rate, and the water vapor-hydrogen gas ratio which give the optimum combination of operating pressure, cross sectional area, number of sections, and volume of catalyst in the tower. Simple directions as to how to make the calculations are included."
Date: March 13, 1943
Creator: Mayer, Harris
Object Type: Report
System: The UNT Digital Library
Determination of general relations for the behavior of turbulent boundary layers (open access)

Determination of general relations for the behavior of turbulent boundary layers

From Summary: "An analysis has been made of a considerable amount of data for turbulent boundary layers along wings and bodies of various shapes in order to determine the fundamental variables that control the development of turbulent boundary layers. It was found that the type of velocity distribution in the boundary layer could be expressed in terms of a single parameter. This parameter was chosen as the ratio of the displacement thickness to the momentum thickness of the boundary layer. The variables that control the development of the turbulent boundary layer apparently are: (1) the ratio of the nondimensional pressure gradient, expressed in terms of the local dynamic pressure outside the boundary layer and boundary-layer thickness, to the local skin-friction coefficient and (2) the shape of the boundary layer. An empirical equation has been developed in terms of these variables that, when used with the momentum equation and the skin-friction relation, makes it possible to trace the development of the turbulent boundary layer to the separation point."
Date: April 13, 1943
Creator: von Doenhoff, Albert E. & Tetervin, Neal
Object Type: Report
System: The UNT Digital Library
Jet-boundary corrections for reflection-plane models in rectangular wind tunnels (open access)

Jet-boundary corrections for reflection-plane models in rectangular wind tunnels

A detailed method for determining the jet-boundary corrections for reflection-plane models in rectangular wind tunnels is presented. The method includes the determination of the tunnel span local distribution and the derivation of equations for the corrections to the angle of attack, the lift and drag coefficients, and the pitching-, rolling-, yawing-, and hinge-moment coefficients. The principle effects of aerodynamic induction and of the boundary-induced curvature of the streamlines have been considered. An example is included to illustrate the method. Numerical values of the more important corrections for reflection-plane models in 7 by 10-foot closed wind tunnels are presented.
Date: April 13, 1943
Creator: Swanson, Robert S. & Toll, Thomas A.
Object Type: Report
System: The UNT Digital Library
The Flow of a Compressible Fluid Past a Curved Surface (open access)

The Flow of a Compressible Fluid Past a Curved Surface

"An iteration method is employed to obtain the flow of a compressible fluid past a curved surface. The first approximation which leads to the Prandtl-Glauert rule, is based on the assumption that the flow differs but little from a pure translation. The iteration process then consists in improving this first approximation in order that it will apply to a flow differing from pure translatory motion to a greater degree. The method fails when the Mach number of the undisturbed stream reaches unity but permits a transition from subsonic to supersonic conditions without the appearance of a compression shock" (p. 305).
Date: September 13, 1943
Creator: Kaplan, Carl
Object Type: Report
System: The UNT Digital Library