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  Partner: UNT Libraries Government Documents Department
 Decade: 1940-1949
 Year: 1942
 Collection: Technical Report Archive and Image Library
Coal-Mine Accidents in the United States, 1940

Coal-Mine Accidents in the United States, 1940

Date: 1942
Creator: Adams, William W.; Geyer, L. E. & Parry, M. G.
Description: Report compiled by the U.S. Bureau of Mines including statistics on fatal and non-fatal accidents in coal mines located in the United States as well as data regarding the various operations (e.g., number of miners employed and average production). The information is organized into tables for comparison and the text draws some overall conclusions in the summary.
Contributing Partner: UNT Libraries Government Documents Department
Column strength of magnesium alloy AM-57S

Column strength of magnesium alloy AM-57S

Date: July 1, 1942
Creator: Holt, M
Description: Tests were made to determine the column strength of extruded magnesium alloy AM-57S. Column specimens were tested with round ends and with flat ends. It was found that the compressive properties should be used in computations for column strengths rather than the tensile properties because the compressive yield strength was approximately one-half the tensile yield strength. A formula for the column strength of magnesium alloy AM-57S is given.
Contributing Partner: UNT Libraries Government Documents Department
Comparison of Intercooler Characteristics

Comparison of Intercooler Characteristics

Date: November 1, 1942
Creator: Valerino, Michael F
Description: No abstract available.
Contributing Partner: UNT Libraries Government Documents Department
A comparison of the results from general tank tests of 1/6- and 1/12-full-size models of the British Singapore IIC flying boat

A comparison of the results from general tank tests of 1/6- and 1/12-full-size models of the British Singapore IIC flying boat

Date: August 1, 1942
Creator: Truscott, Starr & Dawson, John R
Description: A 1/6-full-size model of the hull of the British Singapore IIC flying boat was tested in the NACA tank. The results are given in the form of charts and are compared with the results of previous tests made in the NACA tank of a 1/12-full-size model, published in NACA T.N. No. 580, and with the results of tests made in the British R.A.E. tank of another 1/6-full-size model of the same hull. When the data from the tests of the 1/6- and 1/12-full-size models were compared on the basis of Froude's law of comparison, differences were found. This fact supported the belief that the small scale of the model and the use of a model that was too small to suit the equipment of the NACA tank had caused the results of the tests of the 1/12-full-size model to be less reliable than the results of the tests of the 1/6-full-size model. The results of the tests of the two models agreed sufficiently well to show that test of a small model, if made meticulously and with suitable equipment, may give useable results, but that a larger model should be used whenever feasible. The results of the NACA tests of ...
Contributing Partner: UNT Libraries Government Documents Department
Comparison of tightness of 78 degrees machine-countersunk rivets driven in holes prepared with 78 degrees and 82 degrees countersinking tools

Comparison of tightness of 78 degrees machine-countersunk rivets driven in holes prepared with 78 degrees and 82 degrees countersinking tools

Date: September 1, 1942
Creator: Mandel, Merven W
Description: None
Contributing Partner: UNT Libraries Government Documents Department
The Compressible Potential Flow Past Elliptic Symmetrical Cylinders at Zero Angle of Attack and with No Circulation

The Compressible Potential Flow Past Elliptic Symmetrical Cylinders at Zero Angle of Attack and with No Circulation

Date: October 1, 1942
Creator: Hantzsche, W. & Wendt, H.
Description: For the tunnel corrections of compressible flows those profiles are of interest for which at least the second approximation of the Janzen-Rayleigh method can be applied in closed form. One such case is presented by certain elliptical symmetrical cylinders located in the center of a tunnel with fixed walls and whose maximum velocity, incompressible, is twice the velocity of flow. In the numerical solution the maximum velocity at the profile and the tunnel wall as well as the entry of sonic velocity is computed. The velocity distribution past the contour and in the minimum cross section at various Mach numbers is illustrated on a worked out-example.
Contributing Partner: UNT Libraries Government Documents Department
Condensation trails : where they occur and what can be done about them

Condensation trails : where they occur and what can be done about them

Date: September 1, 1942
Creator: Pearson, H A
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Construction of finned aluminum muffs for aircraft engine cylinder barrels

Construction of finned aluminum muffs for aircraft engine cylinder barrels

Date: April 1, 1942
Creator: unknown
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Contribution to the Design of Plywood Shells

Contribution to the Design of Plywood Shells

Date: October 1, 1942
Creator: Blumrich, S.
Description: The writer sets out to prove by calculation and experiment that by extensive utilization of the skin to carry axial load (reduction of stringer spacing) the stringer sections can be made small enough to afford a substantial saving in structural weight. This saving ranges from 5 to about 40 percent.
Contributing Partner: UNT Libraries Government Documents Department
Contribution to the ideal efficiency of screw propellers

Contribution to the ideal efficiency of screw propellers

Date: January 1, 1942
Creator: Hoff, Wilhelm
Description: The stipulation of best thrust distribution is applied to the annular elements of the screw propeller with infinitely many blades in frictionless, incompressible flow and an ideal jet propulsion system derived possessing hyperbolic angular velocity distribution along the blade radius and combining the advantage of uniform thrust distribution over the section with minimum slipstream and rotation losses. This system is then compared with a propeller possessing the same angular velocity at all blade elements and the best possible thrust distribution secured by means of an induced efficiency varying uniformly over the radius. Lastly, the case of the lightly loaded propeller also is discussed.
Contributing Partner: UNT Libraries Government Documents Department
Control-motion studies of the PBM-3 flying boat in abrupt pull-ups

Control-motion studies of the PBM-3 flying boat in abrupt pull-ups

Date: November 1, 1942
Creator: Smull, Leland K
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Control of Torsional Vibrations by Pendulum Masses

Control of Torsional Vibrations by Pendulum Masses

Date: November 1, 1942
Creator: Stieglitz, Albert
Description: Various versions of pendulum masses have been developed abroad within the past few years by means of which resonant vibrations of rotating shafts can be eliminated at a given tuning. They are already successfully employed on radial engines in the form of pendulous counterweights. Compared with the commonly known torsional vibration dampers, the pendulum masses have the advantage of being structurally very simple, requiring no internal damping and being capable of completely eliminating certain vibrations. Unexplained, so far, remains the problem of behavior of pendulum masses in other critical zones to which they are not tuned, their dynamic behavior at some tuning other than in resonance, and their effect within a compound vibration system and at simultaneous application of several differently tuned pendulous masses. These problems are analyzed in the present report. The results constitute an enlargement of the scope of application of pendulum masses, especially for in-line engines. Among other things it is found that the natural frequency of a system can be raised by means of a correspondingly tuned pendulum mass. The formulas necessary for the design of any practical version are developed, and a pendulum mass having two different natural frequencies simultaneously is described.
Contributing Partner: UNT Libraries Government Documents Department
Cooling in cruising flight with low fuel-air ratios

Cooling in cruising flight with low fuel-air ratios

Date: June 1, 1942
Creator: Wilson, Herbert A , Jr
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Cooling investigation of a B-24D engine-nacelle installation in the NACA full-scale tunnel

Cooling investigation of a B-24D engine-nacelle installation in the NACA full-scale tunnel

Date: November 1, 1942
Creator: Guryansky, Eugene R
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Correlation of data on the statistical theory of turbulence

Correlation of data on the statistical theory of turbulence

Date: March 1, 1942
Creator: Wieghardt, K
Description: The statistical theory of turbulence affords an excellent medium for representing the kinematic conditions in turbulent flow and also serves as a valuable aid to exact experimental research. But it is still not developed enough for solving dynamic processes. Even in the simplest case of isotropic turbulence the calculation of the correlation curve or of the decrement of turbulence invariably reaches a point where clear-cut assumptions, such as omission of the inertia terms, or, earlier, mixing length assumptions or even merely general dimensional considerations, must be made.
Contributing Partner: UNT Libraries Government Documents Department
The critical compression load for a universal testing machine when the specimen is loaded through knife edges

The critical compression load for a universal testing machine when the specimen is loaded through knife edges

Date: September 1, 1942
Creator: Lundquist, Eugene E & Schwartz, Edward B
Description: The results of a theoretical and experimental investigation to determine the critical compression load for a universal testing machine are presented for specimens loaded through knife edges. The critical load for the testing machine is the load at which one of the loading heads becomes laterally instable in relation to the other. For very short specimens the critical load was found to be less than the rated capacity given by the manufacturer for the machine. A load-length diagram is proposed for defining the safe limits of the test region for the machine. Although this report is particularly concerned with a universal testing machine of a certain type, the basic theory which led to the derivation of the general equation for the critical load, P (sub cr) = alpha L can be applied to any testing machine operated in compression where the specimen is loaded through knife edges. In this equation, L is the length of the specimen between knife edges and alpha is the force necessary to displace the upper end of the specimen unit horizontal distance relative to the lower end of the specimen in a direction normal to the knife edges through which the specimen is loaded.
Contributing Partner: UNT Libraries Government Documents Department
Critical Compressive Stress for Flat Rectangular Plates Supported Along All Edges and Elastically Restrained Against Rotation along the Unloaded Edges

Critical Compressive Stress for Flat Rectangular Plates Supported Along All Edges and Elastically Restrained Against Rotation along the Unloaded Edges

Date: January 1, 1942
Creator: Lundquist, Eugene E & Stowell, Elbridge Z
Description: A chart is presented for the values of the coefficient in the formula for the critical compressive stress at which buckling may be expected to occur in flat rectangular plates supported along all edges and, in addition, elastically restrained against rotation along the unloaded edges. The mathematical derivations of the formulas required in the construction of the chart are given.
Contributing Partner: UNT Libraries Government Documents Department
Critical Compressive Stress for Outstanding Flanges

Critical Compressive Stress for Outstanding Flanges

Date: January 1, 1942
Creator: Lundquist, Eugene E & Stowell, Elbridge Z
Description: A chart is presented for the values of the coefficient in the formula for the critical compressive stress at which buckling may be expected to occur in outstanding flanges. These flanges are flat rectangular plates supported along the loaded edges, supported and elastically restrained along one unloaded edge, and free along the other unloaded edge. The mathematical derivations of the formulas required for construction of the chart are given.
Contributing Partner: UNT Libraries Government Documents Department
The cross-flow plate-type intercooler

The cross-flow plate-type intercooler

Date: April 1, 1942
Creator: Valerino, Michael F
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Curing of resin-wood combinations by high-frequency heating

Curing of resin-wood combinations by high-frequency heating

Date: December 1, 1942
Creator: Von Hippel, Arthur R & Dietz, A G H
Description: None
Contributing Partner: UNT Libraries Government Documents Department
A description of the Ju 88 airplane anti-icing equipment

A description of the Ju 88 airplane anti-icing equipment

Date: September 1, 1942
Creator: Jackson, Richard
Description: None
Contributing Partner: UNT Libraries Government Documents Department
The design of propeller blade roots

The design of propeller blade roots

Date: January 1, 1942
Creator: Cordes, G
Description: Predicated on the assumption of certain normal conditions for engine and propeller, simple expressions for the static and dynamic stresses of propeller blade roots are evolved. They, in combination with the fatigue strength diagram of the employed material, afford for each engine power one certain operating point by which the state of stress serving as a basis for the design of the root is defined. Different stress cases must be analyzed, depending on the vibration tendency of engine and use of propeller. The solution affords an insight into the possible introduction of different size classes of propeller.
Contributing Partner: UNT Libraries Government Documents Department
Design of tools for press-countersinking or dimpling 0.040-inch-thick-24S-T sheet

Design of tools for press-countersinking or dimpling 0.040-inch-thick-24S-T sheet

Date: August 1, 1942
Creator: Templin, R L & Fogwell, J W
Description: A set of dimpling tools was designed for 0.040-inch 24S-T sheet and flush-type rivets 1/8 inch in diameter with 100 degree countersunk heads. The dimples produced under different conditions of pressure, sheet thickness, and drill diameter are presented as cross-sectional photographs magnified 20 times. The most satisfactory values for the dimpling tools were found to be: maximum punch diameter, 0.231 inch; maximum die diameter, 0.223 inch; maximum mandrel diameter, 0.128 inch; dimple angle, 100 degree; punch springback angle, 1 1/2 degree; and die springback angle, 2 degree.
Contributing Partner: UNT Libraries Government Documents Department
Determination of optimum plan forms for control surfaces

Determination of optimum plan forms for control surfaces

Date: January 1, 1942
Creator: Jones, Robert T & Cohen, Doris
Description: Solutions found for a range of airfoil plan forms indicate that, regardless of the characteristics of the tail surface, the chord of the rudder or of the elevator should be very nearly constant over its span. The optimum ailerons are also of a characteristic shape, varying little with the plan form of the wing.
Contributing Partner: UNT Libraries Government Documents Department