UNT Libraries Government Documents Department - 24 Matching Results

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Air force and three moments for F-5-L Seaplane

Description: From Introduction: "A model of the F-5-L seaplane was made, verified, and tested at 40 miles an hour in the 8' x 8' tunnel for lift and drag, also for pitching, yawing and rolling moments. Subsequently, the yawing moment test was repeated with a modified fin. The results are reported without VL scale correction."
Date: February 1922
Item Type: Refine your search to only Report
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An automatic speed control for wind tunnels

Description: Described here is an automatic control that has been used in several forms in wind tunnels at the Washington Navy Yard. The form now in use with the 8-foot tunnel at the Navy Yard is considered here. Details of the design and operation of the automatic control system are given. Leads from a Pitot tube are joined to an inverted cup manometer located above a rheostat. When the sliding weight of this instrument is set to a given notch, say for 40 m.p.h, the beam tip vibrates between two electric c… more
Date: February 1928
Creator: Zahm, A. F.
Item Type: Refine your search to only Report
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Causes of cracking of ignition cable

Description: From Summary: "The experiments described here show that the cracking at sharp bends, observed in the insulation of internal combustion engine high tension ignition wires after service, is due to a chemical attack upon the rubber by the ozone produced by the electric discharge that takes place at the surface of the cable. This cracking does not occur if the insulating material is not under tension, or if the cable is surrounded by some medium other than air. But it does occur even if the insulat… more
Date: February 1921
Creator: Dempsey, J. B. & Silsbee, F. B.
Item Type: Refine your search to only Report
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Corrosion Embrittlement of Duralumin. V: Results of Weather-Exposure Tests

Description: In a series of weather exposure tests of sheet duralumin, upon which accelerated corrosion tests in the laboratory by the wet-and-dry corrosion method in a sodium chloride solution has already been carried out, a close parallelism between the results of the two kinds of tests was found to exist. The exposure tests showed that the lack of permanence of sheet duralumin is largely, if not entirely, due to corrosion. A corrosion attack of an intercrystalline nature is very largely responsible for t… more
Date: February 1929
Creator: Rawdon, Henry S.
Item Type: Refine your search to only Report
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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, G.
Item Type: Refine your search to only Report
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Effect of the Reversal of Air Flow Upon the Discharge Coefficient of Durley Orifices

Description: Experiments were conducted to obtain information on the relationship between the coefficients for flow in two directions through thin plate orifices at low velocities. The results indicate that the ratio of the orifice discharge coefficient from standard orifice C(sub s)(sup 1) to the discharge coefficient from the reverse flow C(sub s) is always less than unity with increasing ratio of box area to orifice area. Even for areas as low as twenty, the ratios of the coefficients are not much less t… more
Date: February 1921
Creator: Ware, Marsden
Item Type: Refine your search to only Report
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Effect of the Reversal of Air Flow Upon the Discharge Coefficient of Durley Orifices

Description: Note presenting an experiment to obtain information regarding the relationship between the coefficients for flow in the two directions through an inlet. The results indicate that the ratio of the orifice discharge coefficient from standard orifice to the discharge coefficient from reverse flow is always less than unity, but approaches unity with increasing ratio of box area to orifice area, and that even for a ratio of areas as low as twenty the ratios of the coefficients is not much less than … more
Date: February 1921
Creator: Ware, Marsden
Item Type: Refine your search to only Report
open access

Impact Tests for Woods

Description: Although it is well known that the strength of wood depends greatly upon the time the wood is under the load, little consideration has been given to this fact in testing materials for airplanes. Here, results are given of impact tests on clear, straight grained spruce. Transverse tests were conducted for comparison. Both Izod and Charpy impact tests were conducted. Results are given primarily in tabular and graphical form.
Date: February 1922
Item Type: Refine your search to only Report
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Increasing the Compression Pressure in an Engine by Using a Long Intake Pipe

Description: "During some tests of a one-cylinder engine, using gas oil (diesel engine oil, specific gravity 0.86 at 60 F) with solid injection and compression ignition, it was found to be necessary to increase either the jacket water temperature or the compression pressure in order to start the engine. It was found that a sufficient increase in compression pressure could be obtained simply by attaching a long pipe to the inlet flange of the cylinder. However, since no data were available giving the values … more
Date: February 1924
Creator: Matthews, Robertson & Gardiner, Arthur W.
Item Type: Refine your search to only Report
open access

Induced Drag of Multiplanes

Description: "The most important part of the resistance or drag of a wing system, the induced drag, can be calculated theoretically, when the distribution of lift on the individual wings is known. The calculation is based upon the assumption that the lift on the wings is distributed along the wing in proportion to the ordinates of a semi-ellipse. Formulas and numerical tables are given for calculating the drag. In this connection, the most favorable arrangements of biplanes and triplanes are discussed and t… more
Date: February 1924
Creator: Prandtl, L.
Item Type: Refine your search to only Report
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Interference of Multiplane Wings Having Elliptical Lift Distribution

Description: In calculating the self-induction of a wing surface, elliptical lift distribution is assumed, while in calculating the mutual induction or interference of two wing surfaces, a uniform distribution of the lift along the wing has hitherto been assumed. Whether the results of these calculations are substantially altered by assuming an elliptical lift distribution (which is just as probable as uniform distribution) is examined here.
Date: February 1924
Creator: von Sanden, H.
Item Type: Refine your search to only Report
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Loads and Calculations of Army Airplanes

Description: By comparing airplanes of known strength that have resisted all the usual and even extreme air loads with those that under like conditions were found to be insufficiently strong, the researchers, aided by scientific investigations, developed standards which are satisfactory for the calculation of airplane structures. Given here are standards applicable to loads on wing trusses, load factors for use in stress analysis, load factors required in sand testing, loads on control surfaces, loads on wi… more
Date: February 1921
Creator: Stelmachowski
Item Type: Refine your search to only Report
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Model Supports and Their Effects on the Results of Wind Tunnel Tests

Description: "The airflow about a model while being tested is often sufficiently affected by the model support to lead to erroneous conclusions unless appropriate corrections are used. In this paper some new material on the subject is presented, together with a review of the airfoil support corrections used in several other laboratories" (p. 1).
Date: February 1923
Creator: Bacon, David L.
Item Type: Refine your search to only Report
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A New Method for the Prediction of Airplane Performance

Description: A new method for the prediction of airplane performance in level and climbing flight, together with complete information regarding propeller speeds, is described in this report. Developed from Bairstow's system and making use of American absolute coefficients, this method has advantages of simplicity and brevity.
Date: February 1929
Creator: Lesley, E. P. & Reid, E. G.
Item Type: Refine your search to only Report
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Practical Method for Balancing Airplane Moments

Description: "The present contribution is the sequel to a paper written by Messrs. R. Fuchs, L. Hopf, and H. Hamburger, and proposes to show that the methods therein contained can be practically utilized in computations. Furthermore, the calculations leading up to the diagram of moments for three airplanes, whose performance in war service gave reason for complaint, are analyzed. Finally, it is shown what conclusions can be drawn from the diagram of moments with regard to the defects in these planes and wha… more
Date: February 1924
Creator: Hamburger, H.
Item Type: Refine your search to only Report
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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" (p. 1).
Date: February 1926
Creator: Castleman, R. A.
Item Type: Refine your search to only Report
open access

Surface area coefficients for airship envelopes

Description: "In naval architecture, it is customary to determine the wetted surface of a ship by means of some formula which involves the principal dimensions of the design and suitable constants. These formulas of naval architecture may be extended and applied to the calculation of the surface area of airship envelopes by the use of new values of the constants determined for this purpose. Surface area coefficients were calculated from the actual dimensions, surfaces, and volumes of 52 streamline bodies, w… more
Date: February 1922
Creator: Diehl, W. S.
Item Type: Refine your search to only Report
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Tests on an Airplane Model, AEG D I of the Allgemeine Elektricitats Gesellschft, A-G, Airplane Construction Section Conducted at the Gottingen Model Testing Laboratory for Aerodynamics

Description: "Tests were carried out in the small wind tunnel of the Gottingen establishment on a complete model of the AEG D I airplane. The agreement between the model and the complete airplane applies particularly to the wings, which have ribs cut out of sheet metal and built up in exactly the same manner as in the actual airplane. Various series of tests were carried out with this model in which one or the other of the control surfaces were adjusted to various angles, while the others remained in their … more
Date: February 1923
Creator: Munk, Max & Molthan, Wilhelm
Item Type: Refine your search to only Report
open access

The Theory of the Screw Propeller

Description: Given here is a brief review of the fundamental principles of the propeller slip-stream theory and its further development through later researches, which demonstrate the connection between the propeller slip-stream theory and Frounde's so-called 'propeller blade theory.' The propeller slip-stream theory, especially in its improved form, now gives us the basis for determining the mutual influence of the parts of the blade, so that, in calculating the shape of the blade, we can get along with ce… more
Date: February 1922
Creator: Betz, A.
Item Type: Refine your search to only Report
open access

Triplane Tests

Description: "These experiments were carried out to determine the aerodynamic characteristics of various triplanes, which differed in the relative positions of the wings and, more especially, in the stagger, and in the shape of the wing sections. The tests were restricted to such dispositions as appeared constructively adapted to the plan form considered. Four different sets of wings were used in these tests, three of which had the same cross-section but differed in aspect ratio and in area" (p. 1).
Date: February 1924
Creator: Wieselsberger, C.
Item Type: Refine your search to only Report
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