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Design of power-plant installations pressure-loss characteristics of duct components

Description: "A correlation of what are believed to be the most reliable data available on duct components of aircraft power-plant installations is presented. The information is given in a convenient form and is offered as an aid in designing duct systems and, subject to certain qualifications, as a guide in estimating their performance. The design and performance data include those for straight ducts; simple bends of square, circular, and elliptical cross sections; compound bends; diverging and converging … more
Date: June 1944
Creator: Henry, John R.
open access

Wind-Tunnel Calibration and Correction Procedures for Three-Dimensional Models

Description: "Detailed methods are presented for determining the corrections to results from wind-tunnel tests of three-dimensional models for the effects of the model-support system, the nonuniform air flow in the tunnel, and the tunnel walls or jet boundaries. The procedures for determining the corrections are illustrated by equations and the required tests are discussed. Two general methods that are used for determining and applying the corrections to force tests are discussed" (p. 1).
Date: October 1944
Creator: Swanson, Robert S. & Gillis, Clarence L.
open access

Heat-Transfer Tests of Aqueous Ethylene Glycol Solutions in an Electrically Heated Tube

Description: "As part of an investigation of the cooling characteristics of liquid-cooled engines, tests were conducted with an electrically heated single-tube heat exchanger to determine the heat-transfer characteristics of AN-E-2 ethylene glycol and other ethylene glycol-water mixtures. Similar tests were conducted with water and commercial butanol (n-butyl alcohol) for check purposes. The results of tests conducted at an approximately constant liquid-flow rate of 0.67 pound per second (Reynolds number, 1… more
Date: August 1945
Creator: Bernardo, Everett & Eian, Carroll S.
open access

Heat-Transfer Coefficients for Air Flowing in Round Tubes, in Rectangular Ducts, and Around Finned Cylinders

Description: Report reviews published data and presents some new data on heat transfer to air flowing in round tubes, in rectangular ducts, and around finned cylinders. The available data for heat transfer to air in straight ducts of rectangular and circular cross section have been correlated in plots of Stanton number versus Reynolds number to provide a background for the study of the data for finned cylinders. Equations are recommended for both the streamlined and turbulent regions, and data are presented… more
Date: February 1945
Creator: Drexel, Roger E. & McAdams, William H.
open access

Fatigue Strength and Related Characteristics of Aircraft Joints 1: Comparison of Spot-Weld and Rivet Patterns in 24S-T Alclad and 75S-T Alclad

Description: Report contains detailed results of a number of fatigue tests on spot-welded joints in aluminum alloys. The tests described include: (1) fatigue tests on spot-welded lap joints in sheets of unequal thickness of alclad 24s-t. These tests indicate that the fatigue strength of a spot-welded joint in sheets of two different gages is slightly higher than that of a similar joint in two sheets of the thinner gage but definitely lower than that of a similar joint in two sheets of the thicker gage. (2) … more
Date: December 1944
Creator: Russell, H. W.; Jackson, L. R.; Grover, H. J. & Beaver, W. W.
open access

Fatigue strength and related characteristics of joints in 24S-T Alclad sheet

Description: Report includes tension fatigue test results on the following types of samples of 0.040-inch alclad 24s-t: (1) monoblock sheet samples as received and after a post-aging heat treatment, (2) "sheet efficiency" samples (two equally stressed sheets joined by a single transverse row of spot welds) both as received and after post-aging, (3) spot-welded lap-joint samples as received and after post-aging, and (4) roll-welded lap-joint samples. (author).
Date: May 1944
Creator: Russell, H. W.; Jackson, L. R.; Grover, H. J. & Beaver, W. W.
open access

Effect of Propeller-Axis Angle of Attack on Thrust Distribution Over the Propeller Disk in Relation to Wake-Survey Measurement of Thrust

Description: "Tests were made to investigate the variation of thrust distribution over the propeller disk with angle of pitch of the propeller thrust axis and to determine the disposition and the minimum number of rakes necessary to measure the propeller thrust. The tests were made at a low Mach number for a low and a high blade angle with the propeller operating at three small angles of pitch, and some of the tests were repeated at a higher Mach number. The data obtained show that, for small angles of pitc… more
Date: December 1945
Creator: Pendley, Robert E.
open access

The Effect of Internal Pressure on the Buckling Stress of Thin-Walled Circular Cylinders Under Torsion

Description: "The results of a series of tests to determine the effect of internal pressure on the buckling load of a thin cylinder under an applied torque indicated that internal pressure raises the shear buckling stress. The experimental results were analyzed with the aid of previously developed theory and a simple interaction formula was derived" (p. 1).
Date: May 1944
Creator: Crate, Harold; Batdorf, S. B. & Baab, George W.
open access

Torsion Tests of Stiffened Circular Cylinders

Description: "The design of curved sheet panels to resist shear involves a consideration of several factors: the buckling resistance of the sheet, the stress at which buckling becomes permanent, and the strength which may be developed beyond the buckling limit by tension-field action. Although some experimental as well as theoretical work has been done on the buckling and tension-field phases of this problem, neither of these types of action appears to be very well understood. This report presents the resul… more
Date: May 1944
Creator: Moore, R. L. & Wescoat, C.
open access

Investigation of Flow in an Axially Symmetrical Heated Jet of Air

Description: The work done under this contract falls essentially into two parts: the first part was the design and construction of the equipment and the running of preliminary tests on the 3-inch jet, carried out by Mr. Carl Thiele in 1940; the second part consisting in the measurement in the 1-inch jet flow in an axially symmetrical heated jet of air.
Date: December 1943
Creator: Corrsin, Stanley
open access

Representative Operating Charts of Propellers Tested in the NACA 20-Foot Propeller-Research Tunnel

Description: Report presents the results of tests of full-scale propellers made in the 20-foot propeller-research tunnel (PRT) at the Langley Memorial Aeronautical Laboratory. The power coefficients of all dual-rotating propellers in the report represent the sum of the power coefficients of the front and rear propellers and are for the test conditions in which blade angles of the front and rear propellers were set to absorb approximately equal power at peak efficiency only.
Date: September 1943
Creator: Gray, W. H. & Mastrocola, Nicholas
open access

Effect of normal pressure on the critical compressive and shear stress of curved sheet

Description: Results are presented of tests of two sets of 20 curved-sheet specimens to determine the effect of normal pressure on the critical compressive and shear stress of curved sheets. It was found that normal pressure raised the critical compressive and shear stress of curved sheets except when outward bulging occurred in compression, in which case the critical stress was lowered by normal pressure. (author).
Date: March 1945
Creator: Rafel, Norman & Sandlin, Charles W., Jr.
open access

Pressure-Distribution Measurements of a Model of a Davis Wing Section with Fowler Flap Submitted by Consolidated Aircraft Corporation

Description: Wing pressure distribution diagrams for several angles of attack and flap deflections of 0 degrees, 20 degrees, and 40 degrees are presented. The normal force coefficients agree with lift coefficients obtained in previous test of the same model, except for the maximum lifts with flap deflection. Pressure distribution measurements were made at Reynolds Number of about 6,000,000.
Date: January 1942
Creator: Abbott, Ira H.
open access

Pressure-distribution measurements of two airfoil models with Fowler flaps submitted by Consolidated Aircraft Corporation as alternative wing sections of the XB-32 airplane

Description: Report presenting pressure distribution measurements on two 24-inch chord models equipped with Fowler flaps in the two-dimensional low-turbulence pressure tunnel. Results regarding pressure-distribution diagrams and normal-force and moment coefficients are provided.
Date: January 1942
Creator: Abbott, Ira H.
open access

Pressure-Distribution Measurements of a Low-Drag Airfoil With Slotted Flap Submitted by Curtiss-Wright Corporation

Description: "Pressure-distribution measurements were made at the request of the Materiel Division, U.S. Army Air Corps, on a 24-inch-chord wooden model equipped with a slotted flap and submitted by the Curtiss-Wright Corporation. The tests were made in the Langley two-dimensional tunnel at a Reynolds number of about 5,600,000" (p. 1).
Date: December 1941
Creator: Abbott, Ira H.
open access

Secondary Stresses in Open Box Beams Subjected to Torsion

Description: In open box beams subjected to torsion, secondary stresses arise owing to lateral bending of the spar caps. The present paper outlines a simple method for estimating the magnitude of these stresses and gives the results of tests of an open box beam in the neighborhood of a discontinuity where the cover changed from the top to the bottom of the box.
Date: November 1944
Creator: Kuhn, Paul; Batdorf, S. B. & Brilmyer, Harold G.
open access

Stresses Near the Juncture of a Closed and an Open Torsion Box as Influenced by Bulkhead Flexibility

Description: Report discussing an open box joined to a closed box subjected to torsional loading. A stiff bulkhead and a flexible bulkhead were tested at the discontinuity and the results were compared to a previously published theory. Stress distribution was found to not be sensitive to bulkhead stiffness when the stiffness is large, but the calculations became sensitive to errors in estimating when the stiffness was small.
Date: August 1945
Creator: Kuhn, Paul & Brilmyer, Harold G.
open access

A study of the application of data on various types of flap to the design of fighter brakes

Description: Report presenting an approximate method of applying the available data on various types of flaps in the design of fighter brakes together with several examples of its use. The computed effects of flap type, size, location, and deflection as well as the effects of altitude and initial velocities on braking characteristics are also shown in some examples using the method to determine various flap arrangements.
Date: June 1942
Creator: Purser, Paul E.
open access

Flight Investigation at High Mach Numbers of Several Methods of Measuring Static Pressure on an Airplane Wing

Description: Report discusses an investigation into static pressures in subsonic and supersonic flow over an airplane wing as measured by static-pressure tubes, a static-pressure belt, and orifices flush with the wing surface. The results obtained from the three types of measuring devices and a comparison to theoretical calculations are presented.
Date: November 1944
Creator: Zalovcik, John A. & Daum, Fred L.
open access

Effect of a Trailing-Edge Extension on the Characteristics of a Propeller Section

Description: Report presenting a convenient technical method to evaluate changes in the airfoil characteristics resulting from an extension of the chord at the trailing edge of a propeller blade section. The method determines the change in the angle of zero lift, the ideal angle of attack, and the difference in these angles as a function of the angle and length of the trailing-edge extension.
Date: September 1944
Creator: Theodorsen, Theodore & Stickle, George W.
open access

Variation of peak pitching-moment coefficients for six airfoils as affected by compressibility

Description: Report presenting pressure distribution tests of six NACA 16-series propeller sections with 1-foot chords in the 8-foot high-speed tunnel to determine the compressibility effects on peak section pitching-moment coefficients. Data is presented as curves of peak section pitching-moment coefficient against Mach number, thickness ratio, and camber. The peak pitching-moment coefficients were found to occur in the regions of positive and negative stall.
Date: October 1944
Creator: Cleary, Harold E.
open access

Wind-Tunnel Investigation of Control-Surface Characteristics 3: A Small Aerodynamic Balance of Various Nose Shapes Used With a 30-Percent-Chord Flap on an NACA 0009 Airfoil

Description: Report presenting tests in the 4- by 6-foot vertical wind tunnel of an NACA 0009 airfoil with a 30-percent-chord flap with a small amount of aerodynamic balance. In the investigation, the effect of balance nose shape and gap at the nose of the flap has been determined. The results indicate that, in general, the lift effectiveness of the flap was unaffected by the addition of a small amount of aerodynamic overhang, and the balance effectiveness of the flap was increased.
Date: August 1941
Creator: Ames, Milton B., Jr.
open access

Wind Tunnel Investigation of Control-Surface Characteristics 11: Various Large Overhang and Internal-Type Aerodynamic Balances for a Straight- Contour Flap on the NACA 0015 Airfoil

Description: Report presenting force-test measurements in two-dimensional flow in the 4- by 6-foot vertical tunnel to determine the characteristics of several different shaped overhang-type aerodynamic balances applied to a straight-contour flap mounted on an NACA 0015 airfoil. The flap with blunt-nose overhang was overbalanced throughout certain ranges of flap deflection. Results regarding precision, lift, flap hinge moments, pitching moment, and drag are provided.
Date: January 1943
Creator: Sears, Richard I. & Hoggard, H. Page, Jr.
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