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The Theory of Propellers 3: The Slipstream Contraction With Numerical Values for Two-Blade and Four-Blade Propeller

Description: Report presenting the magnitude of slipstream contraction, which provides information about the conditions of the ultimate wake. Curves and tables are given for the contraction coefficient of two-blade and four-blade propellers for various values of the advance ratio; the contraction coefficient is defined as the contraction in the diameter of the wake helix in terms of the wake diameter at infinity.
Date: November 1944
Creator: Theodorsen, Theodore
Partner: UNT Libraries Government Documents Department
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The Theory of Propellers 4: Thrust, Energy, and Efficiency Formulas for Single- and Dual-Rotating Propellers With Ideal Circulation Distribution

Description: Report presenting simple and exact expressions for the efficiency of single- and dual-rotating propellers with ideal circulation distribution as given by Goldstein functions for single-rotating propellers and by the new functions for dual-rotating propellers from part I of this series. Efficiency is found to depend primarily on a defined load factor and on an axial loss factor. Tables and graphs are included for practical use of the results.
Date: November 1944
Creator: Theodorsen, Theodore
Partner: UNT Libraries Government Documents Department
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The Theory of Propellers 2: Method for Calculating the Axial Interference Velocity

Description: "A technical method is given for calculating the axial interference velocity of a propeller. The method involves the use of certain weight functions P, Q, and F. Numerical values for the weight functions are given for two-blade, three-blade, and six-blade propellers" (p. 53).
Date: September 19, 1944
Creator: Theodorsen, Theodore
Partner: UNT Libraries Government Documents Department
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Charts for Determining Propeller Efficiency

Description: Report presenting a description of a short method of estimating propeller efficiency for a given operating condition. The efficiency is determined for any design condition by evaluating separately from charts the induced losses and the profile-drag losses. The report covers single-rotating propellers of two, three, four, six, and eight blades and includes charts showing the rotational-energy loss for the given operating condition.
Date: September 1944
Creator: Crigler, John L. & Talkin, Herbert W.
Partner: UNT Libraries Government Documents Department
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The effects of hub drag, solidity, dual rotation, and number of blades upon the efficiency of high-pitch propellers

Description: Report presenting an investigation of the effects of hub drag, solidity, dual rotation, and number of blades on the efficiency of high-pitch propellers. Testing occurred with two, three, four, and six-blade single propellers and four and six-blade dual-rotating propellers equipped with spinners and tested at a range of blade angles from 35 to 65 degrees. Results regarding a comparison of the large and small spinners, effects of spinners, comparison of constant-speed propellers, characteristics … more
Date: October 1941
Creator: Reid, Elliott G.
Partner: UNT Libraries Government Documents Department
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Design charts for cross-flow tubular intercoolers charge-across-tube type

Description: Report presenting equations relating the various dimensions, air mass flow, and performance of a cross-flow tubular intercooler in which the charge flows across and the cooling air through the tubes. Design charts are presented from which the intercooler design characteristics and performance can be quickly determined.
Date: January 1941
Creator: Reuter, J. George & Valerino, Michael F.
Partner: UNT Libraries Government Documents Department
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Ground-cooling and flight tests of an airplane equipped with a nose-blower engine cowling

Description: Report presenting flight and ground-cooling tests with a Northrop A-17A attack airplane to determine the merits of a nose-blower engine cowling designed and built at the NACA laboratory. The main objective was to determine the cooling characteristics of the nose blower, especially for ground and low-speed operation. Results regarding the cooling properties, engine pressure drop, and maximum speed and drag are provided.
Date: October 1939
Creator: Turner, L. I., Jr.
Partner: UNT Libraries Government Documents Department
open access

Knock-limited power outputs from a CFR engine using internal coolants 2: six aliphatic amines

Description: Report presenting an investigation to determine the knock-limited performance of AN-F-28, Amendment-2, fuel in a DCFR engine when water solutions of the following aliphatic amines were added as internal coolants: monomethylamine, dimethylamine, ethylendiamine, diethylamine, triethylamine, and butylamine. Results regarding the mean effective pressure, indicated specific fuel competition, indicated specific liquid consumption, and knock-limited inlet-air pressure plotted against fuel-air ratio ar… more
Date: October 1945
Creator: Bellman, Donald R.; Moeckel, W. E. & Evvard, John C.
Partner: UNT Libraries Government Documents Department
open access

Simple Curves for Determining the Effects of Compressibility on Pressure Drop Through Radiators

Description: Report presenting simple curves by which the basic pressure-drop characteristics of unheated tubular radiators can be corrected to operating conditions in which the radiator is heated and in which the Mach number of the tube flow is of appreciable magnitude. The only data required for the use of the curves are the radiator dimensions, the rate of heat input, the pressure and temperature ahead of the radiator, and the rate of mass flow of air through the radiator.
Date: September 1944
Creator: Becker, John V. & Baals, Donald D.
Partner: UNT Libraries Government Documents Department
open access

The Design of Cooling Ducts With Special Reference to the Boundary Layer at the Inlet

Description: "A study has been made of underslung cooling ducts with special references to the problems presented by the boundary layer on the fuselage skin. It was found that good flow can be obtained in such ducts by (1) making the inlet opening of such size that the mean inlet velocity is about 0.6 the free-stream velocity and (2) providing vanes behind as well as ahead of the radiator. Tables to facilitate design are included, together with an example " (p. 1).
Date: December 1940
Creator: Katzoff, S.
Partner: UNT Libraries Government Documents Department
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.
Partner: UNT Libraries Government Documents Department
open access

Design charts for cross-flow tubular intercoolers charge-through-tube type

Description: Report presenting equations relating the various dimensions, air weight flow, and performance of a cross-flow tubular intercooler in which the charge flows through and the cooling air across the tubes. A method of determining and presenting the performance of a given intercooler at various operating conditions is indicated. Results regarding the cooling effectiveness equation, effect of primary intercooler variables, design charts, effect of tube arrangement on intercooler characteristics, and … more
Date: July 1941
Creator: Reuter, J. George & Valerino, Michael F.
Partner: UNT Libraries Government Documents Department
open access

Aerodynamic problems in the design of efficient propellers

Description: From General Analysis: "The purpose of part I of this paper is to show how the loading that gives the minimum induced energy loss can be obtained from rather elementary considerations and to present design charts from which such a plan form can be quickly obtained for any set of design conditions."
Date: August 1942
Creator: Feldman, Lewis
Partner: UNT Libraries Government Documents Department
open access

Tests of Several Model Nacelle-Propeller Arrangements in Front of a Wing

Description: Report presenting an investigation in the 20-foot wind tunnel to determine the drag, propulsive and net efficiencies, and cooling characteristics of several scale-model arrangements of air-cooled radial-engine nacelles and present-day propellers in front of an 18-percent-thick, 5-by-15-foot airfoil. Two 3-blade propellers with differing diameters were tested in conjunction with a 12-inch-diameter nacelle in three positions in front of the wing and with a 16-inch-diameter nacelle in six position… more
Date: September 1939
Creator: McHugh, James G.
Partner: UNT Libraries Government Documents Department
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Drag and propulsive characteristics of air-cooled engine-nacelle installations for two-engine airplanes

Description: Report presenting a study on wing-nacelle propeller arrangements using a two-engine airplane with nacelles varying in diameter. Results regarding the power-off characteristics, propulsive and overall efficiencies, power-on characteristics, and pressure distributions are provided.
Date: December 1940
Creator: Wilson, Herbert A., Jr. & Lehr, Robert R.
Partner: UNT Libraries Government Documents Department
open access

High-speed tests of radial-engine nacelles on a thick low-drag wing

Description: Report presenting testing in the high-speed wind tunnel to determine the drag characteristics of several types of radial-engine nacelle on a low-drag airfoil. The drag coefficients of nacelles incorporating cowling-nose shapes shown by previous tests to be efficient and afterbodies of adequate length were about the same magnitude as commonly obtained for comparable installations on conventional wings. Results regarding the reduction of data, effect of nacelles on lift, and pressures at wing-nac… more
Date: May 1942
Creator: Becker, John V.
Partner: UNT Libraries Government Documents Department
open access

Requirements for Unit Fuel-Injection Systems

Description: "A unit injector was operated under various test conditions with a cam outline giving a high rate of plunger displacement. The rate of discharge of the unit injector followed the plunger displacement for the outwardly opening injection valve (open nozzle) except under conditions of high fuel pressures when the effect of fuel compressibility decreased the rate of discharge as the pressure increased. The rate of discharge for the inwardly opening injection valve (closed nozzle) did not directly f… more
Date: July 1940
Creator: Marsh, Edred T.
Partner: UNT Libraries Government Documents Department
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An Electron-Diffraction Examination of Cast-Iron Piston Rings From Single-Cylinder Aircraft Engine Tests

Description: Report presenting an electron-diffraction examination of cast-iron piston rings used in a single-cylinder test engine, which showed the presence of a layer of graphite covering the surface. The wear curves from the rings studied had shown variation from high rates to very low rates of wear.
Date: February 1945
Creator: Nowick, A. S. & Brockway, L. O.
Partner: UNT Libraries Government Documents Department
open access

A preliminary investigation of exhaust-gas ejectors for ground cooling

Description: Report presenting a preliminary investigation to determine the suitability of ejectors actuated by the exhaust of a radial air-cooled aircraft engine for providing engine cooling air at the ground condition. Various length and diameter ejectors were tested for varying engine power for nine ejectors actuated by the exhaust of individual cylinders and three ejectors actuated by the exhaust of groups of three cylinders.
Date: July 1942
Creator: Manganiello, Eugene J.
Partner: UNT Libraries Government Documents Department
open access

Cascade investigation of buckets for a modern aircraft turbosupercharger

Description: Report presenting a cascade investigation in two-dimensional flow in the 5-inch cascade tunnel and the 1-inch turbine-element testing apparatus to obtain a satisfactory bucket design for use in a modern aircraft turbosupercharger. Results regarding the root sections, pitch sections, and tip sections are provided.
Date: November 1944
Creator: Kantrowitz, Arthur & Erwin, John R.
Partner: UNT Libraries Government Documents Department
open access

An Electron and X-Ray Diffraction Investigation of Surface Changes on Nitrided-Steel Piston Rings During Engine Operation in Nitrided-Steel Cylinders Barrels

Description: Report presenting an examination of new and used nitrided-steel piston rings by electron and X-ray diffraction in a study of the surface changes produced during engine operation. Both new and used rings, examined after degreasing, gave an electron-diffraction pattern consisting of diffuse bands: those from used rings fell at the usual positions of the bands from polished metal surfaces.
Date: March 1945
Creator: Good, J. N. & Brockway, L. O.
Partner: UNT Libraries Government Documents Department
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