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Composition of vapors from boiling nitric acid solutions

Description: From abstract: "The composition of vapors from aqueous nitric acid solutions boiling at 200 mm mercury total pressure is established for solutions containing between - and 67.5 w/o nitric acid. The volatility characteristics of low concentrations of chloride in the same concentration range of nitric acid have been measured in solutions boiling at 200 mm mercury. The effects of chloride concentration and pressure of boiling are evaluated. A spectrophotometric method of the determination of chloride in nitric acid solutions is described."
Date: February 9, 1955
Creator: Crooks, R. C.; Wilson, R. Q.; Bearse, A. E. & Filbert, Robert B.
Partner: UNT Libraries Government Documents Department

Effects of Altitude on Pressure-Flow Relationships in the Vascular Bed of the Hind Limb of the Dog

Description: The purpose of this investigation was to study the effects of decreasing barometric pressure upon the pressure-flow relationships in a peripheral vascular bed in an attempt at better delineation of the autoregulatory mechanisms. A decrease in barometric pressure does influence the transmural pressure and could theoretically affect smooth muscle tone. An evaluation of the extent of the transmural effect is essential to understanding vascular dynamics at altitudes.
Date: August 1966
Creator: Roberts, Donald E.
Partner: UNT Libraries

General free to trim tests in NACA tank no.2 of three 1/8-full-size models of flying-boat hulls at low speeds-NACA models 116E-3K, 120R, and 143

Description: Report presenting tests of representative models of flying boat hulls to determine the resistance at low speeds. Results regarding the effect of load coefficients, resistance coefficients, and towing and drifting calculations are provided.
Date: January 1943
Creator: Carter, Arthur W.
Partner: UNT Libraries Government Documents Department

The resistance coefficient of commercial round wire grids

Description: From Summary: "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 1942
Creator: Eckert, B. & Pflüger, F.
Partner: UNT Libraries Government Documents Department

Resistance of a fifteen-centimeter disk

Description: "The results of this test show that the dynamic scale has very little effect on the drag coefficient of a disk over a wide range of Reynolds Number. A comparison of these results with those of tests made on a series of disks at Göttingen University furnishes a good check on the method of testing in this tunnel" (p. 1).
Date: December 1926
Creator: Shoemaker, James M.
Partner: UNT Libraries Government Documents Department

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" (p. 1).
Date: March 1928
Creator: DeFoe, George L.
Partner: UNT Libraries Government Documents Department

The effect of trim angle on the take-off performance of a flying boat

Description: From Summary: "Data obtained at the N.A.C.A. tank from tests on the models of three flying-boat hulls - N.A.C.A. models 11-A, 16, and 22 - are used to demonstrate the effect of trim angle on water resistance. A specific example is taken, and data from Model 11-A are used to show that the trim angle giving the minimum water resistance will give minimum total air-plus-water resistance. Total-resistance curves for best trimmed angles and other angles are compared for the same example."
Date: January 1934
Creator: Shoemaker, James M. & Dawson, John R.
Partner: UNT Libraries Government Documents Department

General resistance tests on flying-boat hull models

Description: Report re-examining known procedures for handling general resistance testing on flying-boat hull models, with particular attention paid to saving test time and improving the usefulness of the results to designers. While specific testing will likely always be needed, the procedures given in the report for condensing resistance data should make data analysis easier to apply to design.
Date: February 1944
Creator: Locke, F. W. S., Jr.
Partner: UNT Libraries Government Documents Department

The resistance of spheres in wind tunnels and in air

Description: From Summary: "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: 1924
Creator: Bacon, D. L. & Reid, E. G.
Partner: UNT Libraries Government Documents Department

Skin frictional resistance of plane surfaces in air: Abstract of recent German tests, with notes

Description: Given here is the most recent research on skin frictional resistance of plane surfaces in air that was conducted by Dr. Wieselsberger under the direction of Dr. Prandtl of Gottingen University. In all, 16 models were tested. These were divided into four groups, as follows: 1) cloth, in the original condition; 2) cloth, with the nap singed off; 3) cloth, with three coats of dope; and 4) cloth, with six coats of dope. Each group consisted of four models of uniform width, 1 meter, and of lengths of 0.5, 1.0, 1.5, and 2.0 meters.
Date: July 1922
Creator: Diehl, W. S.
Partner: UNT Libraries Government Documents Department

The resistance to air flow of porous materials suitable for boundary-layer-control applications using area suction

Description: "Measurements were made of the resistance to air flow of commercially available porous materials. Three general types of porous media were tested - granular (sintered materials), fibrous (felt cloths and filter papers), and perforated. The flow-resistance characteristics of the porous materials tested are presented in a form intended to assist in the selection of materials for applications to boundary-layer control using area suction" (p. 1).
Date: January 1954
Creator: Dannenberg, Robert E.; Weiberg, James A. & Gambucci, Bruno J.
Partner: UNT Libraries Government Documents Department

Seaplanes floats and hulls. Part 1

Description: This part of the report presents characteristics and graphic representations of water resistance. The laws of similarity are discussed as well as the theory of model tests. The test procedures and model tests of other countries are also discussed.
Date: August 1927
Creator: Herrmann, H.
Partner: UNT Libraries Government Documents Department

Procedure Used at Aluminum Research Laboratories for Determining Type of Attack in Some Aluminum Alloys

Description: Report presenting samples of 17S-T and 24S-T aluminum alloys subjected to accelerated corrosion tests in which the corrosion period was established at 6 hours for samples that had been etched to produce a uniform surface. The results indicate the types of corrosion attack, which are described in standard terminology, and may form a basis for estimating the resistance of the material to corrosion by a comparison of the relative depth and frequency of the corrosive attacks.
Date: August 1942
Creator: Walton, C. J. & Keller, F.
Partner: UNT Libraries Government Documents Department

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.
Date: January 1931
Creator: Schiller, L. & Hermann, R.
Partner: UNT Libraries Government Documents Department

Pressure and Frictional Resistance of a Cylinder at Reynolds Numbers 5,000 to 40,000

Description: This report presents the results of a series of free-jet measurements to determine the pure frictional resistance of a cylinder from the difference between total resistance and pressure at Reynolds Numbers 5,000 to 40,700. The skin friction is 5 percent of the total resistance at Re = 5,000, and had dropped to 2 percent at Re = 40,000, which supports Thom's theory.
Date: July 1933
Creator: Schiller, L. & Linke, W.
Partner: UNT Libraries Government Documents Department

Experiments With a Built-In or Fuselage Radiator

Description: "The experiments discussed here were performed to determine whether radiators having similar cooling properties offer less resistance when incorporated into the fuselage, than when the hitherto customary arrangement is employed, with the radiator in the free air current more or less independent of the fuselage. The experiments indicated that the quantity of air flowing through the radiator is greatest when the fuselage and the radiator are separate. However, separate radiators cause more air resistance" (p. 1).
Date: May 1923
Creator: Wieselsberger, C.
Partner: UNT Libraries Government Documents Department

The Effect of the Nature of Surfaces on Resistance as Tested on Struts

Description: The chief concern was to measure the variations of resistance brought about by the nature of the surface of the struts. The struts were spanned with aviation linen, and then covered with one coat of varnish. The top surface was not perfectly smooth after this treatment, being slightly rough owing to the threads and raised fibers of the fabric. The results of the measurements of the surfaces are shown by the dotted lines of the curves plotted in several figures.
Date: February 1921
Creator: Wieselsberger, Ing. G.
Partner: UNT Libraries Government Documents Department

New Data on the Laws of Fluid Resistance

Description: Thus far, all attempts at the quantitative determination of drag, on the basis of the theory of viscous fluids, have met with but slight success. For this reason, whenever a more accurate knowledge of the drag is desirable, it must be determined by experiment. Here, a few experimental results are given on the drag of a cylinder exposed to a stream of air at right angles to its axis. It is shown that the drag depends on the absolute dimensions of the body and the velocity and viscosity of the fluid in a much more complex manner than has heretofore been supposed.
Date: March 1922
Creator: Wieselsberger, C.
Partner: UNT Libraries Government Documents Department

Study of the Resistance Offered by Propellers Rotating on an Airstream

Description: This report presents a series of tests conducted to verify the formula for thrust P = q(exp 2) D(exp 2) V(exp 2), where P represents thrust, V the velocity of the airstream, D the diameter of the propeller, and q the lifting quality of a comparative propeller which is called the conjugate propeller.
Date: April 1921
Creator: Lame, M.
Partner: UNT Libraries Government Documents Department

Turbulence and Mechanism of Resistance on Spheres and Cylinders

Description: The nature of turbulent flow through pipes and around obstacles is analyzed and illustrated by photographs of turbulence on screens and straighteners. It is shown that the reversal of flow and of the resistance law on spheres is not explainable by Prandtl's turbulence in the boundary layer. The investigation of the analogous phenomena on the cylinder yields a reversal of the total field of flow.
Date: January 1932
Creator: Ahlborn, Fr.
Partner: UNT Libraries Government Documents Department

On Floats and Float Tests

Description: The principal source of information on float resistance is the model test. In view of the insuperable difficulties opposing any attempt at theoretical treatment of the resistance problem, particularly at attitudes which tend toward satisfactory take-off, such as the transitory stage to planing, the towing test is and will remain the primary method for some time.
Date: September 1931
Creator: Seewald, Friedrich
Partner: UNT Libraries Government Documents Department