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Residual stress analysis of overspeeded disk with central hole by x-ray diffraction

Description: An X-ray - diffraction analysis of residual surface stresses after plastic strain was introduced in a parallel-sided 3S-O aluminum disk with a central hole by two types of centrifugal overspeed is reported. Both tangential and radial stresses were generally tensile with large local variations near the hole where surface stresses may have been partly superficial. These stresses were both tensile and compressive dependent on the distance from the disk center when mass compression was effected near the hole.
Date: July 23, 1948
Creator: Good, James N

Resistance and cooling power of various radiators

Description: This reports combines the wind tunnel results of radiator tests made at the Navy Aerodynamical Laboratory in Washington during the summers of 1921, 1925, and 1926. In all, 13 radiators of various types and capacities were given complete tests for figure of merit. Twelve of these were tested for resistance to water flow and a fourteenth radiator was tested for air resistance alone, its heat dissipating capacity being known. All the tests were conducted in the 8 by 8 foot tunnel, or in its 4 by 8 foot restriction, by the writer and under conditions as nearly the same as possible. That is to say, as far as possible, the general arrangement and condition of the apparatus, the observation intervals, the ratio of water flow per unit of cooling surface, the differential temperatures, and the air speeds were the same for all.
Date: January 1, 1928
Creator: Smith, R H

The resistance coefficient of commercial round wire grids

Description: The resistance coefficients of commercial types of round wire grids were examined for the purpose of obtaining the necessary data on supercharger test stands for throttling the inducted air to a pressure corresponding to a desired air density. The measurements of the coefficients ranged up to Reynolds numbers of 1000. In the arrangement of two grids in tandem, which was necessary in order to obtain high resistance coefficients with the solidity, that is, mesh density of grid, was found to be accompanied by a further relationship with the mutual spacing of the individual grids.
Date: January 1, 1942
Creator: Eckert, B. & Pfluger, F.

Resistance of a plate in parallel flow at low Reynolds numbers

Description: The present paper gives the results of measurements of the resistance of a plate placed parallel to the flow in the range of Reynolds numbers from 10 to 2300; in this range the resistance deviates from the formula of Blasius. The lower limit of validity of the Blasius formula is determined and also the increase in resistance at the edges parallel to the flow in the case of a plate of finite width.
Date: November 1, 1951
Creator: Janour, Zbynek

Resistance of Materials to Attack by Liquid Metals

Description: From Forward: "As their contribution, the Metallurgy Division of Argonne National Laboratory was asked to assemble all available unclassified and declassifiable data on the resistance of materials to attack by liquid metals. The resulting collation of data is contained in this report."
Date: July 1950
Creator: Kelman, LeRoy R.; Wilkinson, Walter D. & Yaggee, Frank L.

Resistance of plates and pipes at high Reynolds numbers

Description: It was learned that the law of resistance for high R values does not follow the simple powers, and that the powers, which can be obtained approximately for the velocity distribution, gradually change. Since, moreover, very important investigations have recently been made on the resistance of plates at very high R values, it seemed of interest to apply the above line of reasoning to the new general law of resistance. For this purpose, the resistance and velocity distribution along the plate must always be equal to the values of the pipe flow at the corresponding Reynolds number. We made two kinds of calculations, of which the one given here is the simpler and more practical and also agrees better with the experimental results.
Date: January 1, 1931
Creator: Schiller, L & Hermann, R

The resistance of spheres in wind tunnels and in air

Description: To supplement the standardization tests now in progress at several laboratories, a broad investigation of the resistance of spheres in wind tunnels and free air has been carried out by the National Advisory Committee for Aeronautics. The subject has been classed in aerodynamic research, and in consequence there is available a great mass of data from previous investigations. This material was given careful consideration in laying out the research, and explanation of practically all the disagreement between former experiments has resulted. A satisfactory confirmation of Reynolds law has been accomplished, the effect of means of support determined, the range of experiment greatly extended by work in the new variable density wind tunnel, and the effects of turbulence investigated by work in the tunnels and by towing and dropping tests in free air. It is concluded that the erratic nature of most of the previous work is due to support interference and differing turbulence conditions. While the question of support has been investigated thoroughly, a systematic and comprehensive study of the effects of scale and quality of turbulence will be necessary to complete the problem, as this phase was given only general treatment.
Date: January 1, 1924
Creator: Bacon, D L & Reid, E G

Resistance of streamline wires

Description: This note contains the results of tests to determine the resistance of four sizes of streamline wire. The investigation was conducted in the six-inch wind tunnel of the National Advisory Committee for Aeronautics. The tests were made at various velocities and it was found that the resistance of streamline wires was considerably less than that of round wires of equivalent strength. Scale effect was also found since, with an increase of Reynolds Number, a decrease in the resistance coefficient was obtained.
Date: March 1, 1928
Creator: Defoe, George L

The resistance of three series of flying boat-hulls as affected by length-beam ratio

Description: Report presents correlation of data obtained from several independent length-beam-ratio investigations to determine the general effect of length-beam ratio on the resistance characteristics of three series of flying-boat hulls. An optimum length-beam ratio was found beyond which no further reduction in hydrodynamic resistance occurred. The optimum ratio depended on the hull lines of any given mode series.
Date: October 1945
Creator: Land, Norman S.; Bidwell, Jerold M. & Goldenbaum, David M.

Resistance of transparent plastics to impact

Description: The problem of developing a windshield for aircraft which will withstand the effect of bird impacts during flight is a difficult one, as an estimate of the striking energy will indicate. If the average speed of the airplane is considered to be about 200 miles per hour and that of the bird about 70 miles per hour, the speed of the bird relative to the airplane may be as great as 400 feet per second. If a 4-pound bird is involved, a maximum impact energy of approximately 10,000 foot-pounds must be dissipated. To obtain this energy in a drop test in the Washington Monument, it would be necessary to drop a 20-pound weight down the 500-foot shaft. For both theoretical and practical reasons, it is necessary to keep the mass and speed more nearly like those to be encountered. However, to get an impact of about 10,000 foot-pounds with a 4-pound falling body, it would be necessary to drop it from a height of approximately one-half mile, neglecting air resistance. These facts will indicate some of the experimental obstacles in the way of simulating bird impacts against aircraft windshields.
Date: July 1, 1939
Creator: Axilrod, Benjamin M & Kline, Gordon M

Resistance of various materials to attack by molten bismuth-lead eutectic at elevated temperatures

Description: The resistance of 40 materials including alloys, ceramics, ceramals, and pure metals to attack by bismuth-lead eutectic at temperatures between 1500 and 2000 F was investigated. A velocity of 15 feet per second was maintained between the material surface and the bismuth-lead eutectic. Those materials found to be resistant to this attack included 17 of the ceramals and ceramics, graphite, and arc-cast molybdenum. All other materials investigated were appreciably attacked by the eutectic in the form of uniform attack, cavitation, or pitting, as indicated by metallographic analysis. No evidence of intergranular corrosion was observed in any of the materials studied in this investigation. Disintegration rates were estimated in mils per year from linear measurements taken before and after the specimens were subjected to attack by the molten eutectic.
Date: September 26, 1951
Creator: Gangler, James J & Engel, Walter J

Resistance Tests of a L/L6 Size Model of the Hughes-Kaiser Flying Boat, NACA Model 183

Description: Tank tests were made of a hull model of the Hughes-Kaiser cargo airplane for estimates of take-off performance and maximum gross load for take-off. At hump speeds, with the model free to trim, the trim and resistance were high, which resulted in a load-resistance ratio of approximately 4.0 for a gross load coefficient of 0.75. With a 4000,000-lb load, the full size craft may take off in 69 sec over a distance of 5600 ft.
Date: June 1, 1944
Creator: Posner, Jack; Woodward, David R. & Olson, Roland E.

The resistance to the steady motion of small spheres in fluids

Description: There seems to be little reliable information conveniently available as to the resistance encountered by small spheres moving steadily at moderate speeds in fluids. The present paper, while presenting nothing new in the way of either theory or data, has three objects: first to show that published data are sufficient to furnish approximate information; second to present this information in form convenient for computation; and, third to indicate where further research is needed.
Date: February 1, 1926
Creator: Castleman, R A

Resolution of annealing experiments for the study of nonequilibrium states

Description: The two techniques for conducting annealing experiments for the purpose of determining the distribution of atoms of a solid among non equilibrium states are considered. Related definitions for resolving power for annealing with steadily rising temperature and for annealing at a series of fixed temperatures are given. The necessary separation of activation energies for the resolution of two different non equilibrium states is found to be greater in the case of a steadily rising temperature, but of the order of 10 percent of the activation energy for both techniques. The resolving power in the case of a steadily rising temperature is independent of the rate of temperature rise.
Date: September 27, 1951
Creator: Schwed, Philip