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A method for the determination of air infiltration rates in airplane cabins

Description: From Summary: "A method for the experimental determination of the rate of infiltration of air into aircraft cabins during flight has been developed and tested. This method consists of releasing a quantity of gas in the cabin and calculating the infiltration rate from the measured rate of change of the gas concentration. The results of the flight tests indicate that after the infiltration rate is established at one altitude and airspeed, the infiltration rates at other altitudes and airspeeds ca… more
Date: April 1946
Creator: Stalder, Jackson R. & Zeiller, E. Lewis
open access

Foaming Volume and Foam Stability

Description: "A method of measuring foaming volume is described and investigated to establish the critical factors in its operation. Data on foaming volumes and foam stabilities are given for a series of hydrocarbons and for a range of concentrations of aqueous ethylene-glycol solutions. It is shown that the amount of foam formed depends on the machinery of its production as well as on properties of the liquid, whereas the stability of the foam produced, within specified mechanical limitations, is primarily… more
Date: February 1947
Creator: Ross, Sydney
open access

Stress Rupture of Heat Resisting Alloys as a Rate Process

Description: Note presenting the application of the equations of the theory of rate processes to stress rupture in order to predict the experimental stress and temperature dependence of the time for rupture for three heat-resisting alloys. Results regarding stress dependence, temperature dependence of slope factor, and temperature dependence of apparent free energy of activation are provided.
Date: September 1946
Creator: Machlin, E. S. & Nowick, A. S.
open access

Strain-Gage Study of Internally Cooled Exhaust Valves Having Various Throat Designs

Description: Note presenting three internally cooled exhaust valves with the same external dimensions but different throat designs were investigated to determine a method of obtaining increased coolant-flow area with increasing stresses. The valves were statistically loaded to simulate stresses in the throat region caused by valve closure.
Date: August 1946
Creator: Holms, Arthur G. & Faldetta, Richard D.
open access

A Comparison of the Lateral Motion Calculated for Tailless and Conventional Airplanes

Description: Theoretical analysts of lateral dynamic motion of tailless and conventional airplanes was made for fighter and heavy transport. Their reactions to a lateral gust and control power required by each for simple maneuvers were determined and compared. Both types of airplanes require almost identical aileron control power to perform a given maneuver; tailless airplane requires about 1-2 to 1-3 directional control power of conventional airplane. Tailless airplane also shows greatest displacement for … more
Date: February 1947
Creator: Harper, Charles W. & Jones, Arthur L.
open access

Two-dimensional wind-tunnel investigation of a 10.7-percent-thick symmetrical tail section with a 0.40 airfoil-chord control surface and a 0.20 control-surface-chord tab

Description: Report presenting an investigation of a 10.7-percent-thick symmetrical tail section equipped with a flat-side airfoil-chord flap with a flap-chord overhang and a plain flap-chord tab. Airfoil lift, drag, pitching-moment, and flap and tab hinge-moment characteristics were determined at various flap and tab deflections.
Date: June 1947
Creator: Braslow, Albert L.
open access

Tentative Tables for the Properties of the Upper Atmosphere

Description: Note presenting three temperature-height relationships and one composition-height relationship developed by the NACA and tables based on them for pertinent properties of the upper atmosphere. Two sets of tables based on the adopted tentative standard specifications for the upper atmosphere are presented.
Date: January 1947
Creator: Warfield, Calvin N.
open access

Experimental Investigation of the Stress Distribution Around Reinforced Circular Cut-Outs in Skin Stringer Panels Under Axial Loads

Description: Note presenting results of strain surveys around four reinforced circular cut-outs successively made in an axially loaded skin-stringer tension panel. Curves are presented which show the distribution of stringer and shear stresses in the panel and bending stresses in the reinforcing rings.
Date: March 1947
Creator: Farb, Daniel
open access

The Synthesis and Purification of Aromatic Hydrocarbons 2: 1, 2, 4-Trimethylbenzene

Description: Note presenting a new method for the synthesis and purification of a 14-gallon quantity of 1,2,4-trimethylbenzene. The method consists in the chloromethylation of m- and p-xylenes, subsequent formation of ethyl dimethylbenzyl ethers, and hydrogenolysis of the ethers to yield the hydrocarbon. Results regarding chloromethylation of xylene, conversion of dimethylbenzyl chlorides to ethyl dimethylbenzyl ethers, hydrogenolysis of the ethyl dimethylbenzyl ethers, and identification of biproducts are … more
Date: January 1946
Creator: Ebersole, Earl R.
open access

An analysis of the factors that affect the exhaust process of a four-stroke-cycle reciprocating engine

Description: From Introduction: "An investigation was made to determine the relative significance of the factors that affect the exhaust process; the effects that an exhaust-process change has on cylinder charging were given special attention. Differential equations of this nature have been developed by Kemble (reference 1) but the forms of these equations are such that general conclusions regarding the various factors affecting the exhaust process cannot be determined."
Date: April 1947
Creator: Stanitz, John D.
open access

Frequency-Response Method for Determination of Dynamic Stability Characteristics of Airplanes With Automatic Controls

Description: Note presenting a frequency-response method for determining the critical control-gearing and hunting oscillations of airplanes with automatic pilots. The method is graphical and has several advantages over the standard numerical procedure based on Routh's discriminant. Several examples are worked out to illustrate the application of the frequency-response method in determining the effect of automatic-pilot lag or lead on critical control gearing and in determining the amplitude and frequency of… more
Date: March 1947
Creator: Greenberg, Harry
open access

Investigations of Free Turbulent Mixing

Description: Note presenting a discussion of the integral relations for flow of the boundary-layer type. It is shown that the characteristic laws of spread of jets, wakes, and so forth, can be obtained directly for the laminar case and, with the help of dimensional reasoning, for the turbulent case as well. Measurements of the mean velocity, the intensity and scale of the turbulent fluctuations, and of the turbulent shear in a two-dimensional mixing zone are presented.
Date: August 1947
Creator: Liepmann, Hans Wolfgang & Laufer, John
open access

Experimental Verification of Two Methods for Computing the Take-Off Ground Run of Propeller-Driven Aircraft

Description: Note presenting a comparison between the measured take-off ground run of an airplane equipped with seven different propeller-engine gear-ratio combinations and the computed distances by two different methods. Results indicated that the values of ground run calculated by Diehl's approximate method checked experimental values with 7 percent but were in error as much as 10 to 15 percent under certain conditions. Improved methods of thrust computation may be required in order to avoid large errors … more
Date: June 1947
Creator: Gasich, Welko E.
open access

Turbosupercharger-Rotor Temperatures in Flight

Description: Note presenting temperatures of a turbosupercharger rotor measured in flight for a variety of conditions by thermocouples, the leads of which were brought away from the turbine by means of rotating slip rings and stationary brushes. A consistent and almost linear relation was shown between turbine temperature at the outer edge of the rim and the effective exhaust-gas temperature at the surfaces of the blades on three successive flights at cruising power.
Date: October 1946
Creator: Bartoo, Edward R.
open access

Effect of brake forming in various tempers on the strength of Alclad 75S-T aluminum-alloy sheet

Description: Results are presented of tests to determine the effect of brake forming in various tempers on the strength of Alclad 75S-T aluminum alloy sheet in the direction parallel to the brake. The tensile and compressive strengths of Alclad 75S-T sheet, formed in the O and W tempers, were either increased or little affected compared with those of similarly treated unformed material. When Alclad 75S-T sheet 'as received' was formed, however, the tensile yield stress was reduced about 7 percent for the wi… more
Date: January 1947
Creator: Woods, Walter & Heimerl, George J.
open access

Axial-flow fan and compressor blade design data on 52.5 degrees stagger and further verification of cascade data by rotor tests

Description: From Summary: "Previous tests of blower-blade sections have been extended by a series of tests at 52.5 degrees stagger. The results of these tests have been combined with the earlier test results and are presented in new blade design charts which supersede those previously presented. An investigation in a test blower over a range of stagger from 44 degrees to 65 degrees has shown that for blades at a solidity of 1.0, the two-dimensional cascade data predict the turning angle to within 1/2 degre… more
Date: April 1947
Creator: Bogdonoff, Seymour M. & Hess, Eugene E.
open access

Interference of Wing and Fuselage From Tests of 30 Combinations With Triangular and Elliptical Fuselages in the NACA Variable-Density Tunnel

Description: Note presenting tests of 12 wing-fuselage combinations employing triangular and 18 employing elliptical fuselages made in the NACA variable-density tunnel as part of a program to investigate at large values of Reynolds number the aerodynamic effects of wing-fuselage interference. The parameters of combination covered in the investigation were the vertical position of the wing with respect to the fuselage axis, wing shape, and wing-fuselage juncture shape.
Date: May 1947
Creator: Sherman, Albert
open access

Effect of the tunnel-wall boundary layer on test results of a wing protruding from a tunnel wall

Description: Report presenting two-dimensional span-loading tests of a two-foot-chord NACA 65(sub 1)-012 airfoil model in the stability tunnel to determine tunnel-wall boundary-layer effects. Testing indicated that a small loss in average load may be expected. Results regarding tunnel-wall velocity profiles, pressure distributions, spanwise surveys, and force and moment coefficients are provided.
Date: April 1947
Creator: Mendelsohn, Robert A. & Polhamus, Josephine F.
open access

Preliminary Analysis of NACA Measurements of Atmospheric Turbulence Within a Thunderstorm - U.S. Weather Bureau Thunderstorm Project

Description: "A general description of the field operations of the U.S. Weather Bureau thunderstorm project conducted in the vicinity of Orlando, Florida during the summer month of 1946 is given. The participation of NACA in this project is described and measurements of atmospheric turbulence taken by NACA are presented for one of the flights. The results indicate that some regions of thunderstorms may present no great hazard to flight, while exceptionally severe conditions of atmospheric turbulence may occ… more
Date: March 1947
Creator: Tolefson, Harold B.
open access

In-line aircraft-engine bearing loads 3: main-bearing loads

Description: Report presenting the application of dimensional analysis to the computation of the main bearing of a V-type in-line aircraft engine. Two crankshafts have been considered, one designed for higher operating speed than the other. Two types of engines are considered: one for regular V-type engines and one for production V-type engines.
Date: February 1947
Creator: Shaw, Milton C. & Macks, E. Fred
open access

Meteorological Conditions Associated With Flight Measurements of Atmospheric Turbulence

Description: "The results obtained from a series of flight measurements of atmospheric turbulence within convective-type clouds and from meteorological soundings are presented together with descriptions of the flights and concurrent weather conditions. These results are presented to provide a background of experience for the forecaster and pilot by illustrating the turbulence conditions as indicated by effective gust velocities in convective-type clouds under spring and summer weather conditions along the e… more
Date: June 1947
Creator: Helfand, B. B.
open access

Effect of Variables in Welding Technique on the Strength of Direct-Current Metal-Arc-Welded Joints in Aircraft Steel 2 - Repeated-Stress Tests of Joints in SAE 4130 Seamless Steel Tubing

Description: "A series of tests were made for the purposes of establishing the effects of several variables in welding technique on the fatigue strength of arc-welded joints in SAE 4130 seamless steel tubing. The variables included type of electrode, speed of welding, current, position, amount of preheat, and other factors which in turn controlled the weld contour, penetration, and depth of the heat-affected zone. A range of joint design was also investigated" (p. 1).
Date: April 1948
Creator: Voldrich, C. B. & Armstrong, E. T.
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