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Theoretical Analysis of the Lateral Stability of a Glider Towed by Twin Parallel Towlines

Description: Report discusses a theoretical analysis of the lateral stability characteristics of a glider towed by two parallel towlines, which was correlated with previously reported dynamic flight testing. The glider appears to possess sufficient stability for satisfactory pilotless towed flight. The main factors affecting stability were the dihedral angle of the glider and the length of the towlines.
Date: November 1943
Creator: Pitkin, Marvin & McKinney, Marion O., Jr.
open access

Wind-Tunnel Tests of a Piston-Type Control Booster on an Airfoil and Aileron Model

Description: "Measurements of control moments were made in the NACA stability tunnel to determine the operational characteristics of a piston-type control booster on an aileron. The booster was so constructed and installed that pressures picked up from the air stream below the wing acted on a pair of pistons. The data are presented in the form of curves of pressure coefficients acting on the pistons, hinge-moment coefficients, and booster coefficients plotted against aileron deflection" (p. 1).
Date: November 1943
Creator: Bird, J. D. & Mendelsohn, Robert A.
open access

Wind Tunnel Tests of Ailerons at Various Speeds 5: Pressure Distributions Over the NACA 66,2-216 and NACA 23012 Airfoils With Various Balances on 0.20-Chord Ailerons

Description: Report presenting pressure distribution testing of an NACA 66,2-216, a = 1.0 airfoil equipped with a blunt nose balance aileron and a sealed internal-balance aileron and of an NACA 23012 airfoil equipped with a Frise aileron and a blunt nose balance aileron in the stability tunnel. Results regarding the section pressure distribution and section loads and moments are provided.
Date: November 1943
Creator: Letko, W. & Denaci, H. G.
open access

Studies on the Determination of Carbon by the Low Pressure Combustion Method

Description: Technical report: The apparatus for the low pressure combustion method of determining carbon in iron and steel has be redesigned to increase the speed of manipulation. It has been tested by running several thousand determinations and found to yield results in good agreement with Wooten's form of the apparatus. A detailed description of the equipment and its manipulation is given together with an account of experimental studies on the method. Results are also shown for the carbon content of c… more
Date: October 20, 1943
Creator: Murray, W M., Jr. & Ashley, S E. Q.
open access

Propellers in yaw

Description: It was realized as early as 1909 that a propeller in yaw develops a side force like that of a fin. In 1917, R. G. Harris expressed this force in terms of the torque coefficient for the unyawed propeller. Of several attempts to express the side force directly in terms of the shape of the blades, however, none has been completely satisfactory. An analysis that incorporates induction effects not adequately covered in previous work and that gives good agreement with experiment over a wide range of … more
Date: October 11, 1943
Creator: Ribner, Herbert S.
open access

Report on Reserves and Production Situation of Vanadiferous and Related Ores in Colorado Plateau Region

Description: From introduction: The general distribution of known deposits of vanadium-bearing sandstone, which also contain some uranium and radium, is shown in figure 1 1/ and Exhibit A, plate 53. 2/ During 1939-41 the Geological Survey made detailed geological studies of these deposits in the Uravan district, Montrose County, Colorado, as well as preliminary examinations in other parts of the Colorado Plateau vanadium region. In 1942 detailed geological studies were made o the deposits in the Egnar-Slick… more
Date: October 10, 1943
Creator: Fischer, Richard P. & Stokes, William Lee
open access

Some Cases of Pile Activity Flattening

Description: Radial flattening of activity in the cores of spherical and cylindrical piles is discussed in connection with pile control and power improvement. Partial flattening as a result of k loss from temperature rise is also considered.
Date: October 10, 1943
Creator: Morehouse, N. & Young, G.
open access

The Diffusion Length and the Utilization of Thermal Neutrons in a Heterogeneous Pile

Description: Abstract: "An accurate calculation is given for the quantity which corresponds to the diffusion length in the theory of the pile. The procedure is to establish a relationship between the diffusion length and the change in thermal utilization from a pile with infinite sides to one with sides of a finite length. The calculation of this change in the thermal utilization is then carried through. Approximation to the answer and numerically exact calculations are given in the report. The results show… more
Date: October 6, 1943
Creator: Plass, Gilbert N.
open access

Analysis of the High-Altitude Cooling of the Ranger SGV-770 D-4 Engine in the Bell XP-77 Airplane

Description: Report presenting an analysis of the cooling installation in the high-altitude XP-77 airplane for the entire altitude range. The engine was tested with the same cylinders, aluminum fins, and turbulent-flow baffles proposed for the high-altitude SCV-770 engine. The report is incomplete.
Date: October 1943
Creator: Nielsen, Jack N. & Schumacher, Lloyd E.
open access

Analysis of Wind-Tunnel Stability and Control Tests in Terms of Flying Qualities in Full-Scale Airplanes

Description: From Summary: "The analysis of results of wind-tunnel stability and control tests of powered airplane models in terms of the flying qualities of full-scale airplanes is advocated. In order to indicate the topics upon which comments are considered desirable in the report of a wind-tunnel stability and control investigation and to demonstrate the nature of the suggested analysis, the present NACA flying-qualities requirements are discussed in relation to wind-tunnel tests. General procedures for … more
Date: October 1943
Creator: Kayten, Gerald G.
open access

Certain Mechanical Strength Properties of Aluminum Alloys 25S-T and X76S-T

Description: Note presenting tests made to determine certain mechanical strength properties of 25S-T aluminum alloy. Results are presented from static tests in tension and torsion, bending fatigue tests employing three different types of testing machines, and from impact tests of notched and unnotched specimens in tension as well as Charpy impact tests made at several low temperatures. These are made in order to study the stresses that propeller blades experience.
Date: October 1943
Creator: Dolan, Thomas J.
open access

Critical Stresses for Plates

Description: Report presenting the basic methods of theoretically calculating the critical stress for plates with elastically restrained edges. Design charts for various types of sections and columns and critical stress for flat plates and curved sheets are provided.
Date: October 1943
Creator: Lundquist, Eugene E. & Schuette, Evan H.
open access

The effect of altitude on bomber performance

Description: Report presenting a study devoted to the analysis of the effect of design and operating altitude on the performance of bombers. The primary emphasis is on range performance and charts are presented with range as a function of wing loading, power loading, and design altitude. Results regarding the range at maximum L/D, range at constant power, and performance charts are provided.
Date: October 1943
Creator: Hill, Paul R. & Crigler, John L.
open access

Effect of Length-Beam Ration on Resistance and Spray of Three Models of Flying-Boat Hulls

Description: Report presenting an investigation of the effect of changes in the length-beam ratio of flying-boat hulls on resistance and spray. A family of three models of hulls of different length-beam ratios was used and, in order to maintain comparable hull sizes, the plan-form areas of the hulls were made approximately equal by keeping equal products of length and beam. Results regarding resistance, spray, and take-off performance are provided.
Date: October 1943
Creator: Bell, Joe W.; Garrison, Charlie C. & Zeck, Howard
open access

Effect of pH on strength of resin bonds

Description: Report presenting an investigation to determine the effect of acid on the strength and aging properties of various types of resin bonds for plywood. The pH values of the birch plywoods, flexural and impact strengths before and after aging of birch plywoods bonded with urea-formaldehyde resins and phenolic resins, and delamination properties of birch plywoods bonded with each type of resin are provided.
Date: October 1943
Creator: Rinker, R. C.; Reinhart, F. W. & Kline, G. M.
open access

Flying qualities of a twin-engine patrol airplane as estimated from wind-tunnel tests

Description: Report presenting an estimate of the flying qualities of a twin-engine patrol airplane from wind-tunnel test results in comparison with flight observations as a possible guide in determining changes which would be necessary to improve these qualities. Results regarding the longitudinal and lateral stability and control of this airplane are provided.
Date: October 1943
Creator: Stevens, Victor I., Jr.
open access

Free-Flight-Tunnel Investigation of the Effect of Mode of Propeller Rotation Upon the Lateral-Stability Characteristics of a Twin-Engine Airplane Model With Single Vertical Tails of Different Size

Description: Report presenting an investigation of the effect of direction of propeller rotation on the dynamic lateral stability characteristics of a twin-engine airplane model equipped with single vertical tails of three different sizes. The effects of flap deflection and amount of power were also studied. The most satisfactory lateral-stability characteristics of the model in flight were encountered for the model with large vertical-tail areas.
Date: October 1943
Creator: Pitkin, Marvin
open access

Heat Transfer Over the Circumference of a Heated Cylinder in Transverse Flow

Description: "A method for recording the local heat-transfer coefficients on bodies in flow was developed. The cylinder surface was kept at constant temperature by the condensation of vapor except for a narrow strip which is heated separately to the same temperature by electricity. The heat-transfer coefficient at each point was determined from the electric heat output and the temperature increase" (p. 1).
Date: October 1943
Creator: Schmidt, Ernst & Wenner, Karl
open access

Investigation of surface irregularities on an NACA 63(420)-416, a=1.0 airfoil section for the Glenn L. Martin Company design 195

Description: Report presenting the results of an investigation made in the two-dimensional low-turbulence pressure tunnel of surface irregularities on a low-drag airfoil section. The primary objective was to determine the effects of riveted and piano-hinge-type skin joints and of an aileron slot of the drag characteristics. Any type of surface irregularities at the front spar were found to cause substantial increase in drag.
Date: October 1943
Creator: Braslow, Albert L.
open access

The Measurement of Fuel-Air Ratio by Analysis of the Oxidized Exhaust Gas

Description: "An investigation was made to determine a method of measuring fuel-air ratio that could be used for test purposes in flight and for checking conventional equipment in the laboratory. Two single-cylinder test engines equipped with typical commercial engine cylinders were used. The fuel-air ratio of the mixture delivered to the engines was determined by direct measurement of the quantity of air and of fuel supplied and also by analysis of the oxidized exhaust gas and of the normal exhaust gas" (p… more
Date: October 1, 1943
Creator: Gerrish, Harold C. & Meem, J. Lawrence, Jr.
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