UNT Libraries Government Documents Department - 12 Matching Results

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Approximate Calculation of Multispar Cantilever and Semicantilever Wings With Parallel Ribs Under Direct and Indirect Loading

Description: A method is presented for approximate static calculation, which is based on the customary assumption of rigid ribs, while taking into account the systematic errors in the calculation results due to this arbitrary assumption. The procedure is given in greater detail for semicantilever and cantilever wings with polygonal spar plan form and for wings under direct loading only. The last example illustrates the advantages of the use of influence lines for such wing structures and their practical interpretation.
Date: August 1932
Creator: Sänger, Eugen

Characteristics of an airfoil as affected by fabric sag

Description: "This report presents the results of tests made at a high value of the Reynolds Number in the N.A.C.A. variable-density wind tunnel to determine the aerodynamic characteristics of an airfoil as affected by fabric sag. Tests were made of two Gottingen 387 airfoils, one having the usual smooth surface and the other having a surface modified to simulate two types of fabric sag. The results of these tests indicate that the usual sagging of the wind covering between ribs has a very small effect on the aerodynamic characteristics of an airfoil" (p. 1).
Date: August 1932
Creator: Ward, Kenneth E.

Effect of engine operating conditions on the vaporization of safety fuels

Description: "Tests were conducted with the N.A.C.A. combustion apparatus to determine the effect of compression ratio and engine temperature on the vaporization of a hydrogenated "safety fuel" during the compression stroke under conditions similar to those in a spark-ignition engine. The effects of fuel boiling temperature on vaporization using gasoline, safety fuel, and Diesel fuel oil was also investigated. The results show that increasing the compression ratio has little effect on the rate of fuel vaporization, but that increasing the air temperature by increasing the engine temperature increases the rate of fuel vaporization" (p. 1).
Date: August 1932
Creator: Rothrock, A. M. & Waldron, C. D.

Experimental Determination of the Thickness of the Boundary Layer Along a Wing Section

Description: "The thickness and course of the boundary layer were measured in flight, in order to determine whether the relations on an airplane and on a shop-made wing can be brought into agreement with the results of wind-tunnel tests and Horst Muller's calculations of the thickness of the boundary layer, as developed from Karman's integral equation for the boundary layer" (p. 1).
Date: August 1932
Creator: Cuno, Otto

Heat dissipation from a finned cylinder at different fin-plane/air-stream angles

Description: This report gives the results of an experimental determination of the temperature distribution in and the heat dissipation from a cylindrical finned surface for various fin-plane/air-stream angles. A steel cylinder 4.5 inches in diameter having slightly tapered fins of 0.30-inch pitch and 0.6 -inch width was equipped with an electrical heating unit furnishing 13 to 248 B.T.U. per hour per square inch of inside wall area. Air at speeds form 30 to 150 miles per hour was directed at seven different angles from 0 degrees to 90 degrees with respect to the fin planes. The tests show the best angle for cooling at all air speeds to be about 45 degrees. With the same temperature for the two conditions and with an air speed of 76 miles per hour, the heat input to the cylinder can be increased 50 percent at 45 degrees fin-plane/air-stream angle over that at 0 degrees.
Date: August 1932
Creator: Schey, Oscar W. & Biermann, Arnold E.

Reduction of Wing Lift by the Drag

Description: Drag and loss of lift of a wing are attributable to the same cause, wake formation, thus indicating that there is some relation between both. The analysis of measurements on Joukowsky sections revealed a typical course of curves for the interdependence between drag and loss of lift. The shape of the curves apparently depends quite regularly on the mean camber and on the thickness of the profile.
Date: August 1932
Creator: Betz, A. & Lotz, J.

Spartan "Cruiser" Commercial Airplane (British): A Six-Seat Low-Wing Cantilever Monoplane

Description: Circular describing the Spartan "Cruiser", which is a six-seat low-wing cantilever commercial monoplane with three engines. Details of the construction, fuselage, wing, tail unit, power plant, fuel system, lubrication system, landing gear, controls, cabin arrangement, characteristics, performance, drawings, and photographs are provided.
Date: August 1932

Strength Tests on Thin-Walled Duralumin Cylinders in Torsion

Description: This report is the first of a series presenting the results of strength tests on thin-walled cylinders and truncated cones of circular and elliptical section; it comprises the results obtained to date from torsion (pure shear) tests on 65 thin-walled duralumin cylinders of circular section with ends clamped to rigid bulkheads. The effect of variations in the length/radius and radius/thickness ratios on the type of failure is indicated, and a semi-empirical equation for the shearing stress at maximum load is given.
Date: August 1932
Creator: Lundquist, Eugene E.