UNT Libraries Government Documents Department - 31 Matching Results

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Adaptor for measuring principal strains with Tuckerman strain gage

Description: Report discussing an adapter which uses three Tuckerman optical strain gages to measure the displacement of the three vortices of an equilateral triangle along lines 120 degrees apart. These displacements are substituted in well-known equations in order to compute the magnitude and direction of the principal strains. Tests of the adaptor indicate that principal strains over a gage length of 1.42 inch may be measured with a systematic error not exceeding 4 percent and a mean observational error of the order of + or minus 0.000006. The maximum observed error in strain was of the order of 0.00006. The directions of principal strains for unidirectional stress were measured with the adaptor with an average error of the order of 1 degree.
Date: June 1943
Creator: Mcpherson, A E

Bearing tests of magnesium-alloy sheet

Description: Bearing tests of AM-3S, AM-52S, and AM-C57S magnesium-alloy sheet in various thicknesses and tempers were made. Bearing yield and ultimate strengths were determined and compared for various edge distances and for various ratios of loading-pin diameter to sheet thickness. Tensile strengths were determined and ratios of average bearing yield and ultimate strength to tensile strength are given. The results of the tests indicated that ultimate bearing strengths increased with edge distances up to 1.5 to 2 times the diameter of the loading pin; that ultimate bearing strengths are a function of the ratio of pin diameter to sheet thickness; and that these properties are effected only slightly by increases in edge distance greater than 1.5 diameters.
Date: June 1, 1943
Creator: Sharp, W H & Moore, R L

Briquetting Subbituminous Coal

Description: Report issued by the Bureau of Mines over briquetting of coal for development of more effective fuel. Materials, equipment, and processes are discussed. This report includes tables, illustrations, and photographs.
Date: June 1943
Creator: Parry, V. F. & Goodman, John B.

Recommended test procedure for aircraft engine turbosupercharger power plants

Description: Report describes a procedure for instrumenting, testing, and presenting the overall characteristics of any engine turbosupercharger installation. The preflight analysis of the system, required testing, importance of accurate data recording, measurements to record, methods of measuring, and presentation of results are also included.
Date: June 1943
Creator: NACA Subcommittee on Recovery of Power from Exhaust Gas

Researches on Preliminary Chemical Reactions in Spark-Ignition Engines

Description: Chemical reactions can demonstrably occur in a fuel-air mixture compressed in the working cylinder of an Otto-cycle (spark ignition) internal-combustion engine even before the charge is ignited by the flame proceeding from the sparking plug. These are the so-called "prelinminary reactions" ("pre-flame" combustion or oxidation), and an exact knowledge of their characteristic development is of great importance for a correct appreciation of the phenomena of engine-knock (detonation), and consequently for its avoidance. Such reactions can be studied either in a working engine cylinder or in a combustion bomb. The first method necessitates a complicated experimental technique, while the second has the disadvantage of enabling only a single reaction to be studied at one time. Consequently, a new series of experiments was inaugurated, conducted in a motored (externally-driven) experimental engine of mixture-compression type, without ignition, the resulting preliminary reactions being detectable and measurable thermometrically.
Date: June 1, 1943
Creator: Muehlner, E.

Resume of hinge-moment data for unshielded horn- balanced control surfaces

Description: Report summarizes the available hinge-moment data for unshielded horn-balanced control surfaces. The purpose is to correlate the available data to assist with estimating the balance characteristics for use in the design and alteration of control surfaces with horn balances. Plan forms and variation of incremental hinge-moment-coefficient slopes with balance coefficients are presented.
Date: June 1943
Creator: Lowry, John G.

Some systematic model experiments on the porpoising characteristics of flying-boat hulls

Description: From Summary: "This report presents the results of systematic model experiments on the hydrodynamic characteristics of flying boats, aimed primarily at developing a comprehensive view of the factors influencing porpoising and of their relative importance. The experiments 'radiated' from a given reference ship; they embrace changes, over reasonably wide ranges, in the value of each of a number of variables, treated independently. The experimental results are summarized in a series of 25 figures, each of which gives the complete data for all the modifications of one variable."
Date: June 1943
Creator: Davidson, Kenneth S. M. & Locke, F. W. S., Jr

Test data on the shear strength of joints assembled with round-head and brazier-head rivets

Description: Report discusses data obtained from testing shear of joints riveted with round-head and brazier-head rivets. The tightness of the rivets is also compared for one value of rivet diameter. The load-displacement curves and comparison of load at various values of permanent displacement are presented for both types of rivets.
Date: June 1943
Creator: Mandel, Merven W. & .Schuette, Evan H.