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The Compressible Potential Flow Past Elliptic Symmetrical Cylinders at Zero Angle of Attack and with No Circulation

Description: "For the tunnel corrections of compressible flows those profiles are of interest for which at least the second approximation of the Janzen-Rayleigh method can be applied in closed form. One such case is presented by certain elliptical symmetrical cylinders located in the center of a tunnel with fixed walls and whose maximum velocity, incompressible, is twice the velocity of flow. In the numerical solution the maximum velocity at the profile and the tunnel wall as well as the entry of sonic velo… more
Date: October 1942
Creator: Hantzsche, W. & Wendt, H.
Item Type: Refine your search to only Report
open access

Construction of Finned Aluminum Muffs for Aircraft Engine Cylinder Barrels

Description: "This report describes the material, cutting-tool development, and machining procedure used in constructing an air-cooled cylinder barrel having a cooling muff with 2-inch fins spaced 1/8 inch. Details of two types of thread form used for the barrel to head assembly with the cooling muff are also presented" (p. 1).
Date: April 1942
Creator: Langley Memorial Aeronautical Laboratory
Item Type: Refine your search to only Report
open access

Contribution to the Design of Plywood Shells

Description: "The writer sets out to prove by calculation and experiment that by extensive utilization of the skin to carry axial load (reduction of stringer spacing) the stringer sections can be made small enough to afford a substantial saving in structural weight. This saving ranges from 5 to about 40 percent" (p. 1).
Date: October 1942
Creator: Blumrich, S.
Item Type: Refine your search to only Report
open access

Contribution to the ideal efficiency of screw propellers

Description: From Summary: "The stipulation of best thrust distribution is applied to the annular elements of the screw propeller with infinitely many blades in frictionless, incompressible flow and an ideal jet propulsion system derived possessing hyperbolic angular velocity distribution along the blade radius and combining the advantage of uniform thrust distribution over the section with minimum slipstream and rotation losses. This system is then compared with a propeller possessing the same angular velo… more
Date: January 1942
Creator: Hoff, Wilhelm
Item Type: Refine your search to only Report
open access

Control-Motion Studies of the PBM-3 Flying Boat in Abrupt Pull-Ups

Description: Report presenting a control-motion study in flight that is part of series covering a range of types and sizes of modern airplanes. This particular one involves the PBM-3 flying boat, which is equipped with a control mechanism typical of the cable-type systems in large transport, cargo, or bomber airplanes as well as those employed in flying boats. The elasticity of the elevator control system of the PBM-3 was such to limit the obtainable acceleration to about 3g for center-of-gravity positions … more
Date: November 1942
Creator: Pearson, Henry A. & Smull, Leland K.
Item Type: Refine your search to only Report
open access

Control of Torsional Vibrations by Pendulum Masses

Description: "Various versions of pendulum masses have been developed abroad within the past few years by means of which resonant vibrations of rotating shafts can be eliminated at a given tuning. They are already successfully employed on radial engines in the form of pendulous counterweights. Compared with the commonly known torsional vibration dampers, the pendulum masses have the advantage of being structurally very simple, requiring no internal damping and being capable of completely eliminating certain… more
Date: November 1942
Creator: Stieglitz, Albert
Item Type: Refine your search to only Report
open access

Cooling in Cruising Flight With Low Fuel-Air Ratios

Description: Report presenting testing of a Pratt & Whitney R-1830-43 engine mounted in a B-24D nacelle in the full-scale wind tunnel in order to investigation the potential improvements of fuel economy. Suggestions for improving the cruising power and cruising range by operating at specified fuel-air ratios are provided.
Date: June 1942
Creator: Silverstein, Abe & Wilson, Herbert A., Jr.
Item Type: Refine your search to only Report
open access

Cooling Investigation of a B-24D Engine-Nacelle Installation in the NACA Full-Scale Tunnel

Description: Report presenting an investigation conducted in the full-scale tunnel to determine methods of improving the cooling of the B-24D engine installation. The B-24D is a four-engine high-wing monoplane having a span of 110 feet, a wing area of 1048 square feet, and a gross weight of 56,000 pounds.
Date: November 1942
Creator: Lehr, Robert R.; Kinghorn, George F. & Guryansky, Eugene R.
Item Type: Refine your search to only Report
open access

Cooling Tests of an Air-Cooled Engine Cylinder With Copper Fins on the Barrel

Description: Report presenting the results of comparative cooling tests run on two Wright C9GC (G-200) cylinders, one with the original steel fins and one with 1-inch spiral copper fins brazed on the barrel. Calculations were also performed using copper and aluminum fins with the same weight as the original steel fins, which showed positive results. Results regarding cylinder-temperature correlation, piston-temperature correlation, and comparative performance are also provided.
Date: July 1942
Creator: Sanders, J. C.; Wilsted, H. D. & Mulcahy, B. A.
Item Type: Refine your search to only Report
open access

Correlation of Data on the Statistical Theory of Turbulence

Description: The statistical theory of turbulence affords an excellent medium for representing the kinematic conditions in turbulent flow and also serves as a valuable aid to exact experimental research. But it is still not developed enough for solving dynamic processes. Even in the simplest case of isotropic turbulence the calculation of the correlation curve or of the decrement of turbulence invariably reaches a point where clear-cut assumptions, such as omission of the inertia terms, or, earlier, mixing … more
Date: March 1942
Creator: Wieghardt, K.
Item Type: Refine your search to only Report
open access

The critical compression load for a universal testing machine when the specimen is loaded through knife edges

Description: "The results of a theoretical and experimental investigation to determine the critical compression load for a universal testing machine are presented for specimens loaded through knife edges. The critical load for the testing machine is the load at which one of the loading heads becomes laterally instable in relation to the other. For very short specimens the critical load was found to be less than the rated capacity given by the manufacturer for the machine. A load-length diagram is proposed f… more
Date: September 1942
Creator: Lundquist, Eugene E. & Schwartz, Edward B.
Item Type: Refine your search to only Report
open access

The cross-flow plate-type intercooler

Description: Report presenting a mathematical analysis of plate-type intercooler design for both turbulent and laminar flow. Charts are presented to show how the plate-type intercooler volume, weight, plate area, frontal area, and linear dimensions can be varied without changing the intercooler operating conditions. An experimental investigation was also carried out with a plate-type intercooler unit to check the validity of the heat-transfer and pressure-drop theories for the airflow between very closely s… more
Date: April 1942
Creator: Pinkel, Benjamin; Reuter, J. George & Valerino, Michael F.
Item Type: Refine your search to only Report
open access

Curing of Resin-Wood Combinations by High-Frequency Heating

Description: Note presenting a summary of the results of an investigation of the curing of resin-wood combinations by high-frequency heating. The physical facts pertinent to high-frequency heating are introduced and the procedure is described for measuring dielectric constant and loss from 1 to 100 megacycles. The results indicated that the high-frequency heating process is feasible, flexible, and timesaving.
Date: December 1942
Creator: von Hippel, Arthur R. & Dietz, A. G. H.
Item Type: Refine your search to only Report
open access

Derivation of charts for determining the horizontal tail load variation with any elevator motion

Description: From Summary: "The equations relating the wing and tail loads are derived for a unit elevator displacement. These equations are then converted into a nondimensional form and charts are given by which the wing- and tail-load-increment variation may be determined under dynamic conditions for any type of elevator motion and for various degrees of airplane stability. In order to illustrate the use of the charts, several examples are included in which the wing and tail loads are evaluated for a numb… more
Date: November 23, 1942
Creator: Pearson, Henry A.
Item Type: Refine your search to only Report
open access

A Description of the Ju 88 Airplane Anti-Icing Equipment

Description: Bulletin presenting an examination of a part of the anti-icing equipment for a Ju 88 airplane, including exhaust-air heat exchangers, control valves, air duct system, and air-heated wing panels. Testing was performed on the components and indicated that the thermal ice-prevention equipment can maintain the outer-wing panel free from ice.
Date: September 1942
Creator: Rodert, Lewis A. & Jackson, Richard
Item Type: Refine your search to only Report
open access

The Design of Propeller Blade Roots

Description: Predicated on the assumption of certain normal conditions for engine and propeller, simple expressions for the static and dynamic stresses of propeller blade roots are evolved. They, in combination with the fatigue strength diagram of the employed material, afford for each engine power one certain operating point by which the state of stress serving as a basis for the design of the root is defined. Different stress cases must be analyzed, depending on the vibration tendency of engine and use of… more
Date: January 1942
Creator: Cordes, G.
Item Type: Refine your search to only Report
open access

Design of Tools for Press-Countersinking or Dimpling 0.040-Inch-Thick 24S-T Sheet

Description: "A set of dimpling tools was designed for 0.040-inch 24S-T sheet and flush-type rivets 1/8 inch in diameter with 100 degree countersunk heads. The dimples produced under different conditions of pressure, sheet thickness, and drill diameter are presented as cross-sectional photographs magnified 20 times. The most satisfactory values for the dimpling tools were found to be: maximum punch diameter, 0.231 inch; maximum die diameter, 0.223 inch; maximum mandrel diameter, 0.128 inch; dimple angle, 10… more
Date: August 1942
Creator: Templin, R. L. & Fogwell, J. W.
Item Type: Refine your search to only Report
open access

Determination of the Stability and Control Characteristics of Airplanes from Tests of Powered Models

Description: Report presenting a technique of testing wind tunnel powered models developed as a result of experience gained in the investigation of the static longitudinal and lateral staiblity and control characteristics of several powered models in the 7- by 10-foot wind tunnel. A discussion of the conditions to be investigated, methods of presenting and interpreting the data, and a suggested operating technique are given.
Date: July 1942
Creator: Recant, Isidore G.
Item Type: Refine your search to only Report
open access

The Development of Satisfactory Flying Qualities on the Douglas Dive Bomber, Model SBD-1 Through Flight Testing Successive Modifications in Control-Surface Area, Hinge-Line Location, and Aerodynamic-Balance Nose Shape

Description: Report presenting flight-test data contributing to the development of the present SBD-1 flying qualities based on the interest expressed in the methods used to obtain control-force characteristics on the Douglas Model SBD-1 by minor relocation of control-surface hinge line in combination with modifications in the aerodynamic balance nose shape. Results regarding the stalling characteristics, lateral-directional stability and control, longitudinal stability and control, and design recommendation… more
Date: May 1942
Creator: Root, L. E.
Item Type: Refine your search to only Report
open access

Diagrams for Calculation of Airfoil Lattices

Description: "The field for curved blades is represented by a vortex series with a vortex removed at the blade point. Further, an example of calculation of a curved blade from this series is given, whereby the necessary accuracy required of the different methods in practice is shown according to the case considered" (p. 1).
Date: July 1942
Creator: Betz, Albert
Item Type: Refine your search to only Report
open access

The Direct-Stress Fatigue Strength of 17S-T Aluminum Alloy Throughout the Range From 1/2 to 500,000,000 Cycles of Stress

Description: "Fatigue-tests were conducted on six specimens made from 3/4-inch-diameter 17S-T rolled-and-drawn rod for the purpose of obtaining additional data on the fatigue life of the material at stresses up to the static strength. The specimens were tested in direct tension using a stress range from zero to a maximum in tension. A static testing machine was used to apply repeated loads in the case of the first three specimens; the other three specimens were tested in a direct tension-compression fatigue… more
Date: September 1942
Creator: Hartmann, E. C. & Stickley, G. W.
Item Type: Refine your search to only Report
open access

Drag and Propulsive Characteristics of Air-Cooled Engine-Nacelle Installations for Large Airplane

Description: "An investigation was conducted in the NACA full-scale wind tunnel to determine the drag and the propulsive efficiency of nacelle-propeller arrangements for a large range of nacelle sizes. In contrast with usual tests with a single nacelle, these tests were conducted with nacelle-propeller installations on a large model of a four-engine airplane. Data are presented on the first part of the investigation, covering seven nacelle arrangements with nacelle diameters from 0.53 to 1.5 times the wing … more
Date: 1942
Creator: Silverstein, Abe & Wilson, Herbert A., Jr.
Item Type: Refine your search to only Report
open access

Effect of additions of aromatics on the knocking characteristics of several 100-octane fuels at two engine speeds

Description: Report presenting testing at two engine speeds on six representative fuels rated at 100-octane number by the C.F.R. aviation method. Blends of the fuels with benzene, toluene, xylene, and isopropyl comprise nine other fuels, leading to testing on 15 fuels. Results regarding the tests at 2000 rpm and 250 degrees Fahrenheit inlet-air temperature, at 3100 rpm and 250 degrees Fahrenheit inlet-air temperature, 2000 rpm and 150 degrees Fahrenheit inlet-air temperature, and 3100 rpm and 150 degrees Fa… more
Date: May 1942
Creator: Biermann, Arnold E.; Corrington, Lester C. & Harries, Myron L.
Item Type: Refine your search to only Report
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