National Advisory Committee for Aeronautics (NACA) - 116 Matching Results

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Proposal for a propeller side-force factor

Description: Report discusses a proposal for propeller manufacturers to consider the side-force factor with the activity factor as a fundamental parameter for all blade designs and for the side-force factor to be included in all reports of powered models in wind tunnels. The proposal includes a method for calculating the side-force factor and how it can be used in propeller development. It is shown to be a good index of the relative effectiveness per blade of a yawed propeller in developing side force.
Date: December 1943
Creator: Ribner, Herbert S.
Partner: UNT Libraries Government Documents Department

Method of mounting cylinder blocks of in-line engines on CUE crankcases

Description: Report describes the installation of six-cylinder blocks from two in-line aircraft engines on CUE crankcases, which permits the separate operation of any cylinder as part of a single-cylinder test engine. Using multicylinder-engine blocks for single-cylinder tests is advantageous because there is greater availability of standard engine parts and there is less temperature gradient. Modifications of the crankcase, camshaft-drive mechanism, and operation of the cylinder are described.
Date: July 1944
Creator: Waldron, C. D. & Biermann, A. E.
Partner: UNT Libraries Government Documents Department

Effect of inlet-air temperature and cylinder displacement on charge temperature of internal combustion engines

Description: Report discussing the effect of inlet-air temperature and cylinder displacement on the charge temperature of an internal-combustion engine at the end of the induction stroke. The experiment to test various types of cylinders and their results on the air temperature and pressure is described.
Date: January 1944
Creator: Sanders, Newell D. & Bolz, Ray E.
Partner: UNT Libraries Government Documents Department

Use of water injection to decrease gasoline consumption in an aircraft engine cruising at high power

Description: Report discusses the results of testing water injection on a multicylinder aircraft engine and the potential fuel savings from the procedure. The speeds at which water injection for engine cooling is beneficial are illustrated and information about the manifold pressures and average rear spark-plug-gasket temperatures are also included.
Date: August 1944
Creator: Engelman, Helmuth W. & White, H. Jack
Partner: UNT Libraries Government Documents Department

A positive-replica technique for examining finished metal surfaces and its application to aircraft engine cylinders

Description: Report discusses a method of replica creation and testing of the surface-finish variation of aircraft engine parts subject to wear. In this report, a positive replica is created, the surface is treated, the replica is tested to make sure the fidelity is high enough, and a series of ring-sticking tests are conducted on the replicas. A summary of the results of the testing is also included.
Date: September 1944
Creator: Clark, Thomas P.
Partner: UNT Libraries Government Documents Department

An estimation of the internal-cooling requirements of an aircraft-engine cylinder when using oxygen boost

Description: Report discusses a method developed to estimate the quantities of internal coolants required to prevent overheating of the aircraft cylinder when oxygen boost is applied. The formula and calculations related to inlet-air pressure, added oxygen, added water, added nitrogen, and total fluid weight are detailed.
Date: November 1944
Creator: Evvard, John C. & Moeckel, W. E.
Partner: UNT Libraries Government Documents Department

Calculations of intake-air cooling resulting from water injection and of water recovery from exhaust gas

Description: Report discussing some calculations made for the effects of water in cooling the inlet air of aircraft-engine cylinders. From Summary: "The estimates indicate that the cooling effect of the water on the inlet air can be more extensive than the cooling now obtained with the intercoolers or aftercoolers in the air-induction system. In connection with water recovery from the exhaust gas, the estimates indicate that sufficient water can be recovered from 50 percent of the exhaust gas to provide an inducted water-fuel ratio of 0.5."
Date: August 1944
Creator: Rothrock, Addison M.
Partner: UNT Libraries Government Documents Department

Use of Internal Coolant as a Means of Permitting Increase in Engine Take-Off Power

Description: Engine tests, together with estimates made at Langley Memorial Aeronautical Laboratory, indicate that a 25-percent increase in take-off power can be obtained with present-day aircraft engines without increasing either the knock limit of the fuel or the external cooling requirements of the engine. This increase in power with present fuels and present external cooling is made possible through the use of an internal coolant inducted through the inlet manifold. Estimates on aircraft indicate that this 25-percent increase in power will permit an approximate usable increase of 8.5 percent in the take-off load of existing military airplanes. This increase in load is equivalent to an increase in the weight of gasoline normally carried of between 30 and 65 percent.
Date: January 1, 1944
Creator: Rothrock, Addison M
Partner: UNT Libraries Government Documents Department

Comparative fatigue tests of riveted joints of Alclad 24S-T, Alclad 24S-T81, Alclad 24S-RT, Alclad 24S-T86 and Alclad 75S-T sheet

Description: Report discusses testing performed to determine the fatigue strength of various types of riveted and spot-welded joints in the following aluminum alloys: Alclad 24S-T, 24S-RT, 758-T, 24S-T81, and 24S-T86. Details of the experiment, tensile properties, and information about failure are provided.
Date: August 1945
Creator: Moore, R. L. & Hill, H. N.
Partner: UNT Libraries Government Documents Department

Test data on the shear strength of joints assembled with round-head and brazier-head rivets

Description: Report discusses data obtained from testing shear of joints riveted with round-head and brazier-head rivets. The tightness of the rivets is also compared for one value of rivet diameter. The load-displacement curves and comparison of load at various values of permanent displacement are presented for both types of rivets.
Date: June 1943
Creator: Mandel, Merven W. & Schuette, Evan H.
Partner: UNT Libraries Government Documents Department

End-zone water injection as a means of suppressing knock in a spark-ignition engine

Description: Report discusses the results of an investigation into the effectiveness of water injection into the combustion end zone of a spark-ignition engine cylinder for the suppression of knock. The injection angle was found to be very important for obtaining maximum results. The results of various angles and amounts of water were examined.
Date: September 1944
Creator: Brun, Rinaldo J.; Olsen, H. Lowell & Miller, Cearcy D.
Partner: UNT Libraries Government Documents Department

Effect of Normal Pressure on the Critical Shear Stress of Curved Sheet

Description: In order to determine the critical stresses caused by an outward acting pressure on the upper surface of a wing due to the difference in internal and external pressures, torsional tests were made on two curved-sheet specimens subjected to an outward acting normal pressure. Results show that an outward acting normal pressure appreciable raises the critical shear stress for an unstiffened curved sheet; the absolute increase in critical shear stress is slightly greater for a 30 in. rib spacing than for a 10 in. rib spacing.
Date: January 1, 1943
Creator: Rafel, Norman
Partner: UNT Libraries Government Documents Department

Tests of beams having webs with large circular lightening holes

Description: From Summary: "Strength tests were made on two sets of beams having webs with large circular lightening holes. The main conclusion drawn from the tests is that allowable web stressed derived from pure shear tests and allowable flange stresses derived from compression tests cannot be applied in the design of beams without making corrections for interaction." Pure shear tests and beam tests were performed and the circumstances of failure were investigated.
Date: February 1944
Creator: Levin, L. Ross
Partner: UNT Libraries Government Documents Department

Determination of desirable lengths of Z- and channel-section columns for local-instability tests

Description: From Summary: "Local-instability tests of 24S-T aluminum-alloy formed Z- and channel-section columns were made in order to determine a length of test specimen that would avoid the increased strength associated with short lengths and also permit the occurrence of a convenient buckling pattern. The effect of column length on the critical compressive stress, on the average stress at maximum load, and on the number of half-waves of the buckling pattern is shown."
Date: October 1944
Creator: Heimerl, George J. & Roy, J. Albert
Partner: UNT Libraries Government Documents Department

The longitudinal shear strength required in double-angle columns of 24S-T aluminum alloy

Description: From Summary: "Tests were made of riveted double-angle columns to determine the total rivet strength that is required to make these built-up columns develop the strength predicted by the standard column formulas. Results of the tests led to the conclusion that the required rivet strength may be calculated by the beam method of design."
Date: May 1943
Creator: Kuhn, Paul & Moggio, Edwin M.
Partner: UNT Libraries Government Documents Department

Tests of 10 inch 24S-T aluminum-alloy shear panels with 1-1/2 inch holes 2 : panels having holes with notched edges

Description: Report discusses the results of testing of 10-inch 24S-T aluminum alloy shear panels with 1.5 inch holes with notched edges to determine if a notch decreases the strength of the panel and if reinforcements can overcome the negative effects of the notch. The notch did appear to increase the stress concentration around the holes, but the lack of applicability to real-world scenarios is discussed.
Date: April 1944
Creator: Kuhn, Paul & Levin, L. Ross
Partner: UNT Libraries Government Documents Department

The effect of artificial aging on the tensile properties of alclad 24S-T and 24S-T aluminum alloy

Description: An experimental study was made to determine the effect of artificial aging on the tensile properties of alclad 24S-T and 24S-T aluminum-alloy sheet material. The results of the tests show that certain combinations of aging time and temperature cause a marked increase in the yield strength and a small increase in the ultimate strength; these increases are accompanied by a very large decrease in elongation. A curve is presented that shows the maximum yield strengths that can be obtained by aging this material at various combinations of time and temperature. The higher values of yield stress are obtained in material aged at relatively longer times and lower temperatures.
Date: August 1943
Creator: Kotanchik, Joseph N.; Woods, Walter & Zender, George W.
Partner: UNT Libraries Government Documents Department

The effect of angle of bend between plate elements on the local instability of formed Z-sections

Description: From Summary: "Thirty-nine Z-sections formed from 24S-T aluminum-alloy sheet with the angle of bend between the flanges and the web varying from 5 degrees to 120 degrees were tested as columns. Angles of bend from 30 degrees to 120 degrees had little or no effect on the critical stress or on the average stress at maximum load for local instability of the columns. The lengths of the columns were such that at angles of bend below 30 degrees they failed by Euler buckling."
Date: September 1944
Creator: Roy, J. Albert & Schuette, Evan H.
Partner: UNT Libraries Government Documents Department

Tests of 10-inch 24S-T aluminum-alloy shear panels with 1-1/2-inch holes

Description: Report discusses the results of testing on "10-inch shear panels of 24S-T aluminum alloy with 1.5 inch holes to determine the stress concentration at static rupture and the deformation characteristics" (from Summary). The strength of the perforated specimens is compared to the solid specimens and the critical stresses are computed. The stress at which permanent set occurs was also measured.
Date: June 1943
Creator: Kuhn, Paul & Levin, L. Ross
Partner: UNT Libraries Government Documents Department

Determination of iron contamination of used lubricating oil for use in measuring rates of wear in aircraft engines

Description: Report discusses methods of determining the iron contamination of used lubricating oil in order to study wear rates of piston rings and cylinder barrels of aircraft engines. Two methods of separating iron from used lubricating oil are presented. The results of the analyses of the oil are presented and the methods are evaluated.
Date: March 1944
Creator: Tischler, Adelbert O.
Partner: UNT Libraries Government Documents Department