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A method for computing leading-edge loads

Description: From Summary: "In this report a formula is developed that enables the determination of the proper design load for the portion of the wing forward of the front spar. The formula is inherently rational in concept, as it takes into account the most important variables that affect the leading-edge load, although theoretical rigor has been sacrificed for simplicity and ease of application. Some empirical corrections, based on pressure distribution measurements on the PW-9 and M-3 airplanes have been… more
Date: January 16, 1931
Creator: Rhode, Richard V. & Pearson, Henry A.
Item Type: Refine your search to only Report
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The effect of small angles of yaw and pitch on the characteristics of airplane propellers

Description: This report presents the results of wind tunnel tests to determine the effect on the characteristics of a propeller of inclining the propeller axis at small angles to the relative wind. Tests were made of a full-scale propeller and fuselage combination at four angles of yaw (0 degree, +5 degrees, +10 degrees, +15 degrees), and of a model propeller, nacelle, and wing combination of five angles of pitch (-5 degrees, 0 degree, +5 degrees, +10 degrees and +15 degrees). The results of the full-scale… more
Date: January 20, 1931
Creator: Freeman, Hugh B.
Item Type: Refine your search to only Report
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Airship Model Tests in the Variable Density Wind Tunnel

Description: This report presents the results of wind tunnel tests conducted to determine the aerodynamic characteristics of airship models. Eight Goodyear-Zeppelin airship models were tested in the original closed-throat tunnel. After the tunnel was rebuilt with an open throat a new model was tested, and one of the Goodyear-Zeppelin models was retested. The results indicate that much may be done to determine the drag of airships from evaluations of the pressure and skin-frictional drags on models tested at… more
Date: January 27, 1931
Creator: Abbott, Ira H.
Item Type: Refine your search to only Report
open access

Investigation of the Diaphragm-Type Pressure Cell

Description: "This report relates to various improvements in the process of manufacture of the NACA standard pressure cell. Like most pressure recording devices employing thin diaphragms, they would in general show considerable change in calibration with temperature and also some change of calibration with time or aging effect. The required diaphragm thickness and the desirable rate of mechanical magnification have been determined on the basis of several hundred tests" (p. 507).
Date: February 3, 1931
Creator: Theodorsen, Theodore
Item Type: Refine your search to only Report
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The effect of valve timing upon the performance of a supercharged engine at altitude and an unsupercharged engine at sea level

Description: This investigation was conducted to determine the comparative effects of valve timing on the performance of an unsupercharged engine at sea level and a supercharged engine at altitude. The tests were conducted on the NACA universal test engine. The timing of the four valve events was varied over a wide range; the engine speeds were varied between 1,050 and 1,500 r.p.m.; the compression ratios were varied between 4.35:1 and 7.35:1. The conditions of exhaust pressure and carburetor pressure of a … more
Date: February 4, 1931
Creator: Schey, Oscar W. & Biermann, Arnold E.
Item Type: Refine your search to only Report
open access

The vertical wind tunnel of the National Advisory Committee for Aeronautics

Description: "The vertical open-throat wind tunnel of the National Advisory Committee for Aeronautics is described in this report. The tunnel was built mainly for studying the spinning characteristics of airplane models, but may be used as well for the usual types of wind-tunnel tests. A special spinning balance is being developed to measure the desired forces and moments with the model simulating the spin of an airplane. Satisfactory air flow has been attained with a velocity that is uniform over the jet t… more
Date: February 9, 1931
Creator: Wenzinger, Carl J. & Harris, Thomas A.
Item Type: Refine your search to only Report
open access

The drag characteristics of several airships determined by deceleration tests

Description: This report presents the results of deceleration tests conducted for the purpose of determining the drag characteristics of six airships. The tests were made with airships of various shapes and sizes belonging to the Army, the Navy, and the Goodyear-Zeppelin Corporation. Drag coefficients for the following airships are shown: Army TC-6, TC-10, and TE-2; Navy Los Angeles and ZMC-2; Goodyear Puritan. The coefficients vary from about 0.045 for the small blunt airships to 0.023 for the relatively l… more
Date: March 2, 1931
Creator: Thompson, F. L. & Kirschbaum, H. W.
Item Type: Refine your search to only Report
open access

Span-load distribution as a factor in stability in roll

Description: "This report gives the results of pressure-distribution tests made to study the effects on lateral stability of changing the span-load distribution on a rectangular monoplane wing model of fairly thick section. Three methods of changing the distribution were employed: variation in profile along the span to a thin symmetrical section at the tip, twist from +5 degrees to -15 degrees at the tip, and sweepback from +20 degrees to -20 degrees. The tests were conducted in a 5-foot closed-throat atmos… more
Date: March 4, 1931
Creator: Knight, Montgomery & Noyes, Richard W.
Item Type: Refine your search to only Report
open access

Hydraulics of Fuel-Injection Pumps for Compression-Ignition Engines

Description: "Formulas are derived for computing the instantaneous pressures delivered by a fuel pump. The first derivation considers the compressibility of the fuel and the second, the compressibility, elasticity, and inertia of the fuel. The second derivation follows that given by Sass; it is shown to be the more accurate of the two. Additional formulas are given for determining the resistance losses in the injection tube" (p. 621).
Date: March 6, 1931
Creator: Rothrock, A. M.
Item Type: Refine your search to only Report
open access

A New Principle of Sound Frequency Analysis

Description: "In connection with the study of aircraft and propeller noises, the National Advisory Committee for Aeronautics has developed an instrument for sound-frequency analysis which differs fundamentally from previous types, and which, owing to its simplicity of principle, construction, and operation, has proved to be of value in this investigation. The method is based on the well-known fact that the Ohmic loss in an electrical resistance is equal to the sum of the losses of the harmonic components of… more
Date: March 23, 1931
Creator: Theodorsen, Theodore
Item Type: Refine your search to only Report
open access

Investigation of damping liquids for aircraft instruments 2

Description: "Data are presented on the kinematic viscosity, in the temperature range -50 degrees to +30 degrees C. of pure liquids and of solutions of animal oils, vegetable oils, mineral oils, glycerine, and ethylene glycol in various low freezing point solvents. It is shown that the thermal coefficient of kinematic viscosity as a function of the kinematic viscosity of the solutions of glycerine and ethylene glycol in alcohols is practically independent of the temperature and the chemical composition of t… more
Date: March 28, 1931
Creator: Houseman, M. R. & Keulegan, G. H.
Item Type: Refine your search to only Report
open access

Flame Movement and Pressure Development in an Engine Cylinder

Description: "This investigation describes a visual method for making stroboscopic observations, through a large number of small windows, of the spread of flame throughout the combustion chamber of a gasoline engine. Data, secured by this method on a small engine burning gaseous fuels, are given to show the effects of mixture ratio, spark advance, engine speed, charge density, degree of dilution, compression ratio, and fuel composition on flame movement in the cylinder. Partial indicator diagrams showing pr… more
Date: May 1, 1931
Creator: Marvin, Charles F., Jr. & Best, Robert D.
Item Type: Refine your search to only Report
open access

Combustion in a High-Speed Compression-Ignition Engine

Description: "An investigation conducted to determine the factors which control the combustion in a high-speed compression-ignition engine is presented. Indicator cards were taken with the Farnboro indicator and analyzed according to the tangent method devised by Schweitzer. The analysis show that in a quiescent combustion chamber increasing the time lag of auto-ignition increases the maximum rate of combustion. Increasing the maximum rate of combustion increases the tendency for detonation to occur" (p. 63… more
Date: May 21, 1931
Creator: Rothrock, A. M.
Item Type: Refine your search to only Report
open access

Effect of orifice length-diameter ratio on fuel sprays for compression-ignition engines

Description: "Experimental results on the effect of the length-diameter ratio of the orifice on the spray characteristics, together with a brief analysis of the factors affecting these characteristics, are presented in this report. The length-diameter ratios tested ranged from 0.5 to 10; the orifice diameters from 0.008 to 0.040 inch; and the injection pressures from 2,000 to 8,000 pounds per square inch. The density of the air into which the fuel was discharged was varied from 0.38 to 1.35 pounds per cubic… more
Date: May 27, 1931
Creator: Gelalles, A. G.
Item Type: Refine your search to only Report
open access

The effect of increased carburetor pressure on engine performance at several compression ratios

Description: The object of this investigation was to determine the effect of increasing the carburetor pressures from 30 to 40 inches of mercury, at compression ratios from 3.5 to 7.5, on the power, on the maximum cylinder pressures, on the fuel consumption, and on the other performance characteristics of an engine. A roots-type aircraft-engine supercharger was used to maintain the desired carburetor pressure.
Date: May 29, 1931
Creator: Schey, Oscar W. & Rollin, Vern G.
Item Type: Refine your search to only Report
open access

Ice Prevention on Aircraft by Means of Engine Exhaust Heat and a Technical Study of Heat Transmission From a Clark Y Airfoil

Description: "This investigation was conducted to study the practicability of employing heat as a means of preventing the formation of ice on airplane wings. The report relates essentially to technical problems regarding the extraction of heat from the exhaust gases and its proper distribution over the exposed surfaces. In this connection a separate study has been made to determine the variation of the coefficient of heat transmission along the chord of a Clark Y airfoil. Experiments on ice prevention both … more
Date: June 12, 1931
Creator: Theodorsen, Theodore & Clay, William C.
Item Type: Refine your search to only Report
open access

Drop and Flight Tests on NY-2 Landing Gears Including Measurements of Vertical Velocities at Landing

Description: This investigation was conducted to obtain quantitative information on the effectiveness of three landing gears for the NY-2 (consolidated training) airplane. The investigation consisted of static, drop, and flight tests on landing gears of the oleo-rubber-disk and the mercury rubber-chord types, and flight tests only on a landing gear of the conventional split-axle rubber-cord type. The results show that the oleo gear is the most effective of the three landing gears in minimizing impact forces… more
Date: August 7, 1931
Creator: Peck, W. C. & Beard, A. P.
Item Type: Refine your search to only Report
open access

Penetration and Duration of Fuel Sprays From a Pump Injection System

Description: "High-speed motion pictures were taken of individual fuel sprays from a pump injection system. The changes in the spray-tip penetration with changes in the pump speed, injection-valve opening and closing pressures, discharge-orifice area, injection-tube length and diameter, and pump throttle setting were measured. The pump was used with and without a check valve" (p. 241).
Date: August 24, 1931
Creator: Rothrock, A. M. & Marsh, E. T.
Item Type: Refine your search to only Report
open access

The NACA Apparatus for Studying the Formation and Combustion of Fuel Sprays and the Results From Preliminary Tests

Description: "This report describes the apparatus as designed and constructed at the Langley Memorial Aeronautical Laboratory, for studying the formation and combustion of fuel sprays under conditions closely simulating those occurring in a high-speed compression-ignition engine. The apparatus consists of a single-cylinder modified test engine, a fuel-injection system so designed that a single charge of fuel can be injected into the combustion chamber of the engine, an electric driving motor, and a high-spe… more
Date: August 26, 1931
Creator: Rothrock, A. M.
Item Type: Refine your search to only Report
open access

The Theory of Wind-Tunnel Wall Interference

Description: This report outlines the development of a general theory for the calculation of the effect of the boundaries of the air stream on the flow past an airfoil. Analytical treatments are given for tunnels with horizontal boundaries only, with vertical boundaries only, and with a bottom boundary only. Formulas are developed for the tunnel wall interference in each case for an airfoil located at the center of the tunnel. The correction is given as a function of the width to height ratio of the tunnel.
Date: October 9, 1931
Creator: Theodorsen, Theodore
Item Type: Refine your search to only Report
open access

The Elimination of Fire Hazard Due to Back Fires

Description: "A critical study was made of the operation of a type of back-fire arrester used to reduce the fire hazard of aircraft engines. A flame arrester consisting of a pack or plug of alternate flat and corrugated plates of thin metal was installed in the intake pipe of a gasoline engines; an auxiliary spark plug inserted in the intake manifold permitted the production of artificial back fires at will. It was found possible to design a plug which prevented all back fires from reaching the carburetor" … more
Date: October 13, 1931
Creator: Theodorsen, Theodore & Freeman, Ira M.
Item Type: Refine your search to only Report
open access

Pressure distribution tests on a series of Clark Y biplane cellules with special reference to stability

Description: "The pressure distribution data discussed in this report represents the results of part of an investigation conducted on the factors affecting the aerodynamic safety of airplanes. The present tests were made on semispan, circular-tipped Clark Y airfoil models mounted in the conventional manner on a separation plane. Pressure readings were made simultaneously at all test orifices at each of 20 angles of attack between -8 degrees and +90 degrees. The results of the tests on each wing arrangement … more
Date: October 15, 1931
Creator: Noyes, Richard W.
Item Type: Refine your search to only Report
open access

Tests of nacelle-propeller combinations in various positions with reference to wings. Part I : thick wing-N.A.C.A. cowled nacelle-tractor propeller

Description: This report gives the results in the 20-foot propeller research tunnel of the National Advisory Committee for Aeronautics on the interference drag and propulsive efficiency of a nacelle-propeller combination located in 21 positions with reference to a thick wing. The lift, drag, and propulsive efficiency were obtained at several angles of attack for each of the 21 locations. A net efficiency was derived for determining the over-all effectiveness of each nacelle location. Best results were obtai… more
Date: November 18, 1931
Creator: Wood, Donald H.
Item Type: Refine your search to only Report
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