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Measurements in Flight of the Stability, Lateral Control, and Stalling Characteristics of an Airplane Equipped With Full-Span Zap Flaps and Spoiler-Type Ailerons

Description: Report presenting the stability, lateral-control, and stalling characteristics of an airplane modified to accommodate full-span Zap flaps.The static and dynamic longitudinal and lateral stability was satisfactory, but there were some undesirable lateral-control characteristics, including excessive friction and elasticity.
Date: December 1943
Creator: Spahr, J. Richard & Christophersen, Don R.
Item Type: Refine your search to only Report
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Methods and Charts for Computing Stability Derivatives of a V-Bottom Planing Surface

Description: Report presenting methods and charts for computing stability derivatives of a longitudinally straight V-bottom planing surface representing the forebody of a seaplane float or a flying-boat hull without chine flare. The charts for computing hydrodynamic derivatives were used in calculating the trim limit of stability for angles of dead rise of 10, 20, and 30 degrees.
Date: December 1943
Creator: Benson, James M. & Freihofner, Anton
Item Type: Refine your search to only Report
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Operating Temperatures of a Sodium-Cooled Exhaust Valve as Measured by a Thermocouple

Description: "A thermocouple was installed in the crown of a sodium-cooled exhaust valve. The valve was then tested in an air-cooled engine cylinder and valve temperatures under various engine operating conditions were determined. A temperature of 1337 F was observed at a fuel-air ratio of 0.064, a brake mean effective pressure of 179 pounds per square inch, and an engine speed of 2000 rpm" (p. 1).
Date: December 1943
Creator: Sanders, J. C.; Wilsted, H. D. & Mulcahy, B. A.
Item Type: Refine your search to only Report
open access

Piston Ring Pressure Distribution

Description: "The discovery and introduction of the internal combustion engine has resulted in a very rapid development in machines utilizing the action of a piston. Design has been limited by the internal components of the engine, which has been subjected to ever increasing thermal and mechanical stresses. Of these internal engine components, the piston and piston rings are of particular importance and the momentary position of engine development is not seldom dependent upon the development of both of the … more
Date: December 1943
Creator: Kuhn, M.
Item Type: Refine your search to only Report
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Preliminary Aerodynamic and Structural Tests Showing the Effect of Compressive Load on the Fairness of a Low-Drag Wing Specimen With Chordwise Hat-Section Stiffeners

Description: Report presenting an investigation that is part of a research program to obtain structures suitable for low-drag wings. The purpose of this particular investigation was to study the drag characteristics of an NACA 66(215)-(1.25)16 airfoil specimen of two-spar construction with hat-section chordwise stiffeners after a compressive load comparable with the maximum applied flight load of a modern military airplane has been applied and removed. Results regarding the variation of section drag coeffic… more
Date: December 1943
Creator: Davidson, Milton; Houbolt, John C.; Rafel, Normal & Rossman, Carl A.
Item Type: Refine your search to only Report
open access

A Preliminary Study of Machine-Countersunk Flush Rivets Subjected to a Combined Static and Alternating Shear Load

Description: Report discusses the results of an investigation to study the effect of the height of a rivet head on the number of cycles required to cause failure of a machine-countersunk flush-riveted joint under a combined static and alternating shear load. A tight joint and a loose joint were tested and the number of cycles to failure and location of fatigue failure were compared.
Date: December 1943
Creator: Crate, Harold
Item Type: Refine your search to only Report
open access

Propellers in yaw

Description: Report presenting the propeller forces due to an angular velocity of pitch, which are analyzed and shown to be very small for the pitching velocities that may actually be realized in maneuvers, with the exception of the spin. A dual-rotating propeller in yaw was found to develop up to one-third more side force than a single-rotating propeller.
Date: December 1943
Creator: Ribner, Herbert S.
Item Type: Refine your search to only Report
open access

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.
Item Type: Refine your search to only Report
open access

Some Systematic Model Experiments of the Bow-Spray Characteristics of Flying-Boat Hulls Operating at Low Speeds in Waves

Description: Report discusses the results of testing on several models of flying boats, the XPB2M-1, the XPBB-1, the JRM-1, and 11 other models to determine the effect of bow form on the amount of spray thrown onto the windshield of a flying boat in rough water. Several recommendations for reducing the height and volume of spray are provided. Any change in the hull form that softens the impact between the hull and waves seems to reduce the spray.
Date: December 1943
Creator: Locke, F. W. S., Jr.
Item Type: Refine your search to only Report
open access

The Stability of Isotropic or Orthotopic Cylinders or Flat or Curved Panels, Between and Across Stiffeners, With Any Edge Conditions Between Hinged and Fixed, Under Any Combination of Compression and Shear

Description: Note presenting a theory that is meant to include all factors that are commonly present when determining the stability of isotropic or orthotropic cylinders or flat or curved panels under a variety of characteristics. The theory is based on the energy method and involves a number of approximations, some rather rough. It is a theory of elastic stability and, like other theories, assumes a construction with no imperfections of shape or elasticity.
Date: December 1943
Creator: Donnell, L. H.
Item Type: Refine your search to only Report
open access

A Subpress for Compressive Tests

Description: "A subpress for compressive tests is described. The subpress was designed primarily for use in developing and investigating methods for testing thin sheet metal in compression. Provision was made for testing fixed-end and flat-end specimens with or without various types of lateral support against buckling. Compressive stress-strain data for a sheet of 0.032-inch 24S-RT aluminum alloy were obtained with the subpress by the pack method and by the single-thickness method" (p. 1).
Date: December 1943
Creator: Aitchison, C. S. & Miller, James A.
Item Type: Refine your search to only Report
open access

Tensile and Compressive Tests of Magnesium Alloy J-1 Sheet

Description: Note presenting tensile and compressive stress-strain curves, stress-deviation curves, and secant modulus-stress curves for longitudinal and transverse specimens of magnesium alloy J-1 sheets 0.032 and 0.102 inch thick. Significant differences were found between the tensile and compressive stress-strain curves and between the compressive stress-strain curves for the longitudinal and transverse questions.
Date: December 1943
Creator: Aitchison, C. S. & Miller, James A.
Item Type: Refine your search to only Report
open access

Tests of Inverted Spins in the NACA Free-Spinning Tunnels

Description: "Report discusses the results of inverted-spin tests in 44 airplane models in the NACA free-spinning tunnel. Spins were normally steep and recovery by rudder reversal was generally rapid. Pulling the stick back, deflecting ailerons and rudder together, and crossing them all had an effect on the amount of spin encountered and ease of recovery from spin" (p. 1).
Date: December 1943
Creator: MacDougall, George F., Jr.
Item Type: Refine your search to only Report
open access

Turbulent Friction in the Boundary Layer of a Flat Plate in a Two-Dimensional Compressible Flow at High Speeds

Description: "In the present report an investigation is made on a flat plate in a two-dimensional compressible flow of the effect of compressibility and heating on the turbulent frictional drag coefficient in the boundary layer of an airfoil or wing radiator. The analysis is based on the Prandtl-Karman theory of the turbulent boundary later and the Stodola-Crocco, theorem on the linear relation between the total energy of the flow and its velocity. Formulas are obtained for the velocity distribution and the… more
Date: December 1943
Creator: Frankl, F. & Voishel, V.
Item Type: Refine your search to only Report
open access

Wind-Tunnel Investigation of an NACA 23012 Airfoil With a 0.30-Airfoil-Chord Double Slotted Flap

Description: Report discusses the results of testing of flap position and deflection on the aerodynamic characteristics of a NACA 23012 airfoil with a double slotted flap with a chord 30 percent of the airfoil chord. The maximum lift coefficient, profile-drag coefficients, pitching-moment coefficients, lift, and drag are provided at several positions of the flap. The results were also compared to previous testing on several flap configurations.
Date: December 1943
Creator: Purser, Paul E.; Fischel, Jack & Riebe, John M.
Item Type: Refine your search to only Report
open access

Wind-Tunnel Investigation of Control-Surface Characteristics 15: Various Contour Modifications of a 0.30-Airfoil-Chord Plain Flap on an NACA 66(215)-014 Airfoil

Description: Report presenting force-test measurements in two-dimensional flow made in the 4- by 6-foot vertical tunnel to determine the aerodynamic characteristics of an NACA 66(215)-014 airfoil equipped with true-contour, straight-contour, and beveled-trailing-edge flaps with chords 30 percent of the airfoil chord. The results are presented in the form of aerodynamic section characteristics for several flap deflections and for a sealed and unsealed gap at the flap nose.
Date: December 1943
Creator: Purser, Paul E. & Riebe, John M.
Item Type: Refine your search to only Report
open access

The Resonance Absorption Spectrum of Uranium

Description: A model for the capture spectrum of uranium is introduced in which levels occur at 7, 30, 30+D, 30+2D, ..., ev. Gamma ray and neutron widths are derived from the experimental data for values of D between 10 and 25 ev. The constants of the 7 volt level prove to be independent of D. Extrapolation, using the one level formula, gives a capture cross section at (1/40) ev of 4.9 x 10(24) cm2; this number is, however, quite sensitive to the value taken for the resonance activation. Both neutron and ga… more
Date: November 24, 1943
Creator: Dancoff, Sidney M., 1913-1951
Item Type: Refine your search to only Report
open access

On the plane potential flow past a lattice of arbitrary airfoils

Description: The two-dimensional, incompressible potential flow past a lattice of airfoils of arbitrary shape is investigated theoretically. The problem is treated by usual methods of conformal mapping in several stages, one stage corresponding to the mapping of the framework of the arbitrary line lattice and another significant stage corresponding to the Theodorsen method for the mapping of the arbitrary single wing profile into a circle. A particular feature in the theoretical treatment is the special han… more
Date: November 19, 1943
Creator: Garrick, I. E.
Item Type: Refine your search to only Report
open access

A Theoretical Investigation of the Rolling Oscillations of an Airplane With Ailerons Free

Description: "An analysis is made of the stability of an airplane with ailerons free, with particular attention to the motions when the ailerons have a tendency to float against the wind. The present analysis supersedes the aileron investigation contained in NACA Technical Report no. 709. The equations of motion are first written to include yawing and sideslipping, and it is demonstrated that the principal effects of freeing the ailerons can be determined without regard to these motions" (p. 255).
Date: November 19, 1943
Creator: Cohen, Doris
Item Type: Refine your search to only Report
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