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Aerodynamics of the Fuselage

Description: The present report deals with a number of problems, particularly with the interaction of the fuselage with the wing and tail, on the basis of simple calculating method's derived from greatly idealized concepts. For the fuselage alone it affords, in variance with potential theory, a certain frictional lift in yawed flow, which, similar to the lift of a wing of small aspect ratio, is no longer linearly related to the angle of attack. Nevertheless there exists for this frictional lift something like a neutral stability point the position of which on oblong fuselages appears to be associated with the lift increase of the fuselage in proximity to the zero lift, according to the present experiments. The Pitching moments of the fuselage can be determined with comparatively great reliability so far as the flow conditions in the neighborhood of the axis of the fuselage can be approximated if the fuselage were absent, which, in general, is not very difficult. For the unstable contribution of the fuselage to the static longitudinal stability of the airplane it affords comparatively simple formulas, the evaluation of which offers little difficulty. On the engine nacelles there is, in addition a very substantial wing moment contribution induced by the nonuniform distribution of the transverse displacement flow of the nacelle along the wing chord; this also can be represented by a simple formula. A check on a large number of dissimilar aircraft types regarding the unstable fuselage and nacelle moments disclosed an agreement with the wind-tunnel tests, which should be sufficient for practical requirements. The errors remained throughout within the scope of instrumental accuracy.
Date: December 1942
Creator: Multhopp, H.

Characteristics of beveled-trailing-edge elevators on a typical pursuit fuselage at altitudes simulating-normal flight and spin conditions

Description: Report presenting lift and elevator hinge-moment characteristics were measured on horizontal tail provided with elevators having three different beveled trailing edges. Results regarding fuselage alone and fuselage interference, lift characteristics of fuselage-tail combination, elevator hinge-moment characteristics, drag, and comparison with data from two-dimensional-flow tests are provided.
Date: December 1942
Creator: Gillis, Clarence L.

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.

Effect of airplane design efficiency and engine economy on range

Description: Report presenting an examination of the effects of variations in efficiency parameters, including engine economy, aerodynamic efficiency, and structural efficiency, on airplane performance. Efficiency parameters were found to be extremely ineffective in adjusting the airplane performance to its tactical mission as compared to primary parameters like altitude, power, gross weight, and wing area.
Date: December 1942
Creator: Brevoort, Maurice J.; Stickle, George W. & Hill, Paul R.

The Effect of Various Surface Conditions on Press Fits of Steel Bushings and 17S-T Aluminum-Alloy Fittings

Description: Report presenting testing of specimens of 17S-T aluminum-alloy fittings with pressed-in steel bushings for various surface conditions. The surface conditions tested included bare surfaces, aonidcal coating and steel cadmium-plate, and one surface treated and the other bare, both without lubrication and with Gredag No. 83 as a lubricant. The calculated coefficients of friction for the various press fits for the investigation ranged from 0.33 for the unlubricated contact of bare steel and aluminum to 0.09 for the specimen with the unlubricated cadmium-plated bushing.
Date: December 1942
Creator: Hartmann, E. C. & Reedy, J. F.

An Exploration of the Longitudinal Tensile and Compressive Properties Throughout an Extruded Shape of 24S-T Aluminum Alloy

Description: Note presenting an investigation of tensile and compressive properties of specimens cut from an extruded shape of 24S-T aluminum alloy. The tensile strengths, tensile yield strengths, elongations, and compressive yield strengths of both the uncrystallized and recrystallized portions were determined. The strength of a cross section of an extruded shape is the weighted average of the strengths of the unrecrystallized and the recrystallized areas.
Date: December 1942
Creator: Paul, D. A.

Flight tests of NACA jet-propulsion exhaust stacks on the supermarine spitfire airplane

Description: Report presenting an investigation of the Supermarine Spitfire airplane equipped with exhaust stacks designed according to the jet-propulsion exhaust-stack system developed by the NACA. An increase in the high speed of the airplane of 6 mph was obtained as compared with the airplane equipped with the Rolls Royce exhaust system. Results regarding performance and exhaust-flame visibility are provided.
Date: December 1942
Creator: Turner, L. Richard & White, Maurice D.

An Investigation of Aircraft Heaters 5: Theory and Use of Heat Meters for the Measurement of Rates of Heat Transfer Which Are Independent of Time

Description: Report presenting a description of a meter which will measure the heat flowing through surfaces. Its operation is based on the measurement of the temperature decrease through a fixed thermal resistance. Only the case of heat flow independent of time is discussed in this particular report.
Date: December 1942
Creator: Martinelli, R. C.; Morrin, E. H. & Boelter, L. M. K.

An Investigation of Aircraft Heaters 6: Heat Transfer Equations for the Single Pass Longitudinal Exchanger

Description: Report presenting an analysis of parallel flow and contraflow single pass heat exchangers, together with charts which allow the direct evaluation of the thermal performance of the units without recourse to trail-and-error techniques. The use of equations and charts is illustrated by several examples.
Date: December 1942
Creator: Martinelli, R. C.; Morrin, E. H. & Boelter, L. M. K.

The Limiting Useful Deflections of Corrugated Metal Diaphragms

Description: Note presenting measurements made on a large number of corrugated diaphragms of similar shapes but of various sizes and various metals. Some of the materials studied include phosphor bronze, beryllium copper, A-Nickel, B-Monel, K-Monel, and Inconel. Results regarding pressure deflection, hysteresis, drift, aftereffect, recovery, and zero shift, and design and selection of diaphragms are provided.
Date: December 1942
Creator: Wildhack, W. A. & Goerke, V. H.

A method for determining the rate of heat transfer from a wing or streamline body

Description: From Summary: "A method for calculating the rate of heat transfer from the surface of an airfoil or streamline body is presented. A comparison with the results of an experimental investigation indicates that the accuracy of the method is good. This method may be used to calculate the heat supply necessary for heat de-icing or in ascertaining the heat loss from the fuselage of an aircraft operating at great altitude, for example."
Date: December 1942
Creator: Frick, Charles W., Jr. & McCullough, George B.

A Method of Calculating Bending Stresses Due to Torsion

Description: Report presenting a method for analyzing bending stresses due to torsion in a box with variable cross section and loading by means of a recurrence formula leading to a set of equations identical in form with the well-known three-moment equations. An approximate form of the general method of analysis is presented that eliminates the need of solving a system of equations.
Date: December 1942
Creator: Kuhn, Paul

Multiple-Shift Mechanical Mining in some Bituminous-Coal Mines: Progress Report 4. Extraction of Pillars with Mechanized Equipment

Description: Report issued by the U.S. Bureau of Mines discussing "some methods and practices of mining coal mechanically where operations are conducted on more than one shift" (p. 3). Descriptions of mines, and mining methods are presented. This report includes tables, and illustrations.
Date: December 1942
Creator: Toenges, Albert L.; Maize, Earl R. & Jones, Frank A.

The Performance of a Vaneless Diffuser Fan

Description: The present paper is devoted to the theoretical and experimental investigation of one of the stationary elements of a fan, namely, the vaneless diffuser. The method of computation is based on the principles developed by Pfleiderer (Forschungsarbeiten No. 295). The practical interest of this investigation arises from the fact that the design of the fan guide elements - vaneless diffusers, guide vanes, spiral casing - is far behind the design of the impeller as regards accuracy and. reliability. The computations conducted by the method here presented have shown sufficiently good agreement with the experimental data and indicate the limits within which the values of the coefficient of friction lie.
Date: December 1, 1942
Creator: Polikovsky, V. & Nevelson, M.

Radiation Problems of the Chemical Plant

Description: "Absorption measurements have been made in a large body of water to evaluate the contribution to the radiation intensity produced by the degradation of radiation without absorption. Radiation intensities three times those expected from a simple exponential absorption were found. Scattering from the air of gamma radiation has been measured and has been found to agree satisfactorily with theoretical predictions. The penetration of radiation through curved pipes in shielding has been measured and been found to be a flat topped function. A 2" pipe bent in the arc of a circle of 7' chord and a 10' radius gives a reduction intensity over the intensity in air at the same distance of 2.5X10⁴."
Date: December 12, 1942
Creator: Borst, Lyle B. & Wollan, Ernest Omar