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Wind-Tunnel Investigation of an NACA 23021 Airfoil With Two Sizes of Balanced Split Flaps

Description: Report presenting an investigation in the 7- by 10-foot wind tunnel of a large-chord NACA 23021 airfoil with a 15-percent-chord and a 25-percent-chord balanced split flap of Clark Y profile, to determine the aerodynamic section characteristics of the airfoil-flap combinations as affected by the size, nose location, and deflection of the flaps.
Date: February 1941
Creator: Swanson, Robert S. & Schuldenfrei, Marvin J.
Partner: UNT Libraries Government Documents Department
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Determination of the Effect of Horizontal-Tail Flexibility on Longitudinal Control Characteristics

Description: Report presenting an iteration method for determining the longitudinal control characteristics of a flexible horizontal tail. The method permits factors such as the actual spanwise variation of elasticity and the aerodynamic induction effects due to three-dimensional flow to be accounted for to any degree of accuracy needed. An analysis is also included of the effects of horizontal-tail flexibility on the tail effectiveness, the hinge-moment characteristics, and the control-force gradients in a… more
Date: February 1945
Creator: Harmon, S. M.
Partner: UNT Libraries Government Documents Department
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Wind-Tunnel Investigation of an NACA 23012 Airfoil with a Handley Page Slat and Two Flap Arrangements

Description: Report presenting an investigation in the 7- by 10-foot wind tunnel of an NACA 23012 airfoil equipped with a Handley Page slat and a slotted and a split flap. The purpose of the investigation was to determine the aerodynamic section characteristics of the airfoil with and without flaps as affected by the location of the Handley Page slat. A range of slat-nose locations was investigated both with and without flaps at a constant slat gap.
Date: February 1942
Creator: Schuldenfrei, Marvin J.
Partner: UNT Libraries Government Documents Department
open access

Wind-tunnel tests of a blunt-nose aileron with beveled trailing edge on an NACA 66(215)-216 airfoil with several modifications of aileron nose and adjacent airfoil contour

Description: Report presenting an investigation of ailerons with a beveled trialing edge and a blunt-nose overhang of 35 percent aileron chord on an NACA 66(215)-26 airfoil in two-dimensional flow. Five configurations were tested with various modifications of the aileron nose and adjacent airfoil contour to determine the effect of modifications on lift and aileron hinge-moment characteristics.
Date: February 1945
Creator: Bird, J. D.
Partner: UNT Libraries Government Documents Department
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Wind-Tunnel Investigation of the Characteristics of Blunt-Nose Ailerons on a Tapered Wing

Description: Characteristics are determined for various modifications of 0.155-chord blunt-nose aileron on semispan model of tapered fighter plane wing. Ailerons with 40 percent nose balance reduced high-speed stick forces. Increased balance chord increases effectiveness and reduces high-speed stick forces. Increased balance chord increases effectiveness and reduces adverse effects of gap at aileron hose. Increase of nose radii increased negative slope of curve hinge-movement coefficient plotted against def… more
Date: February 1943
Creator: Purser, Paul E. & Toll, Thomas A.
Partner: UNT Libraries Government Documents Department
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General resistance tests on flying-boat hull models

Description: Report re-examining known procedures for handling general resistance testing on flying-boat hull models, with particular attention paid to saving test time and improving the usefulness of the results to designers. While specific testing will likely always be needed, the procedures given in the report for condensing resistance data should make data analysis easier to apply to design.
Date: February 1944
Creator: Locke, F. W. S., Jr.
Partner: UNT Libraries Government Documents Department
open access

Progress Summary Number 1: Mechanical Properties of Flush-Riveted Joints Submitted by Five Airplane Manufacturers

Description: Summary presenting information on flush-riveted joints for aircraft construction, including the strength, occurrence of defects, and effect of the angle of rivet head. The current tests covers specimens from 15 manufacturers of which 5 series have been completed and are described in this report.
Date: February 1942
Creator: Brueggeman, William Charles
Partner: UNT Libraries Government Documents Department
open access

Wind-Tunnel Investigation of a High-Critical-Speed Fuselage Scoop Including the Effects of Boundary Layer

Description: Report presenting a large air scoop designed for high critical speed, which has been tested in the 8-foot high-speed tunnel on the fuselage of a scale fighter-type airplane. The effects of boundary layer on scoop characteristics were found to be important at all inlet-velocity ratios. Results regarding the boundary-layer surveys, characteristics of original scoop installation, and characteristics of scoop with boundary-layer passage are provided.
Date: February 1945
Creator: Smith, Norman F. & Baals, Donald D.
Partner: UNT Libraries Government Documents Department
open access

Wind-Tunnel Investigation of Control-Surface Characteristics: [Part] 18 - A Linked Overhang Aerodynamic Balance

Description: Report presenting wind-tunnel testing in two-dimensional flow to investigate the aerodynamic characteristics of a flap balanced by a large overhang linked to deflect more slowly than the flap. Three lengths of blunt-nose overhang were tested linked to a 0.30-airfoil-chord straight-contour flap on an NACA 66-009 airfoil. Results regarding lift, hinge moment, drag, pitching moment, and practical considerations are provided.
Date: February 1944
Creator: Sears, Richard I. & Liddell, Robert B.
Partner: UNT Libraries Government Documents Department
open access

Effects of propeller operation and angle of yaw on the distribution of the load on the horizontal tail surface of a typical pursuit airplane

Description: Report presenting measurements in the full-scale tunnel of the pressure distribution over the horizontal tail surface of a typical pursuit airplane in order to determine the effects of propeller operation and angle of yaw on the tail load distribution. Most of the tests were made with the propeller operating to simulate climb conditions, high-speed dives, and pull-ups to various normal accelerations for a range of angles of yaw. Results regarding chordwise pressure distributions, spanwise distr… more
Date: February 1944
Creator: Sweberg, Harold H. & Dingeldein, Richard C.
Partner: UNT Libraries Government Documents Department
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Aerodynamic Characteristics of Four NACA Airfoil Sections Designed for Helicopter Rotor Blades

Description: "The purpose of the present work is to extend the previous investigation and to derive additional airfoil sections designed to minimize the undesirable characteristics of the previously tested airfoils. The tests of these additional airfoils were made in the Langley two-dimensional low-turbulence tunnel (LTT)" (p. 2).
Date: February 1946
Creator: Stivers, Louis S., Jr. & Rice, Fred J., Jr.
Partner: UNT Libraries Government Documents Department
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A Theoretical Investigation of Longitudinal Stability of Airplanes With Free Controls Including Effect of Friction in Control System

Description: "The relation between the elevator hinge-moment parameters and the control forces for changes in forward speed and in maneuvers is shown for several values of static stability and elevator mass balance" (p. 1). Factors affecting stability positively and negatively are presented and potential modifications to the elevator control system are provided. The amount of solid friction present was found to be one of the greatest predictors of instability.
Date: February 1944
Creator: Greenberg, Harry & Sternfield, Leonard
Partner: UNT Libraries Government Documents Department
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Strain Measurements and Strength Tests on the Tension Side of a Box Beam With Flat Cover

Description: Report discusses the shear and normal stresses caused by a load applied until failure on the tension side of an open box beam with a flat stiffened cover. The maximum strain was found to be much less than in solid tensile specimens of the same material. Special attention is paid to the variation in strains at various parts on the beam and the potential effects of rivet holes and riveting, which requires further testing.
Date: February 1945
Creator: Chiarito, Patrick T. & Diskin, Simon H.
Partner: UNT Libraries Government Documents Department
open access

Compressive Strength of Flat Panels With Z-Section Stiffeners

Description: Report presenting compression testing on several series of flat panels with Z-section stiffeners with varying relative dimensions. The data presented show the effect of dimension ratio on the buckling stress for the sheet and on average stress at maximum load.
Date: February 1944
Creator: Rossman, Carl A.; Bartone, Leonard M. & Dobrowski, Charles V.
Partner: UNT Libraries Government Documents Department
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Determination of the Stability and Control Characteristics of a Tailless All-Wing Airplane Model with Sweepback in the Langley Free-Flight Tunnel

Description: Force and flight tests were performance on an all-wing model with windmilling propellers. Tests were conducted with deflected and retracted flaps, with and without auxiliary vertical tail surfaces, and with different centers of gravity and trim coefficients. Results indicate serious reduction of stick-fixed longitudinal stability because of wing-tip stalling at high lift coefficient. Directional stability without vertical tail is undesirably low. Low effective dihedral should be maintained. Ele… more
Date: February 1945
Creator: Campbell, John P. & Seacord, Charles L., Jr.
Partner: UNT Libraries Government Documents Department
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Comparative Tests of the Strength and Tightness of Commercial Flush Rivets of One Type and NACA Flush Rivets in Machine-Countersunk and Counterpunched Joints

Description: Report discusses an investigation that was conducted to compare the strength and tightness of machine-countersunk flush-riveted joints assembled with NACA flush rivets and a type of commercial flush rivet. A comparison was also generated between the strength and tightness of counterpunched flush-riveted joints assembled with the same types of rivet. NACA's flush-riveted joints tended to be stronger and tighter than the commercial joints.
Date: February 1, 1944
Creator: Mandel, Merven W.
Partner: UNT Libraries Government Documents Department
open access

The belt method for measuring pressure distribution

Description: "The measurement of pressure distribution may be accomplished rapidly for any number of locations deemed necessary in model or full-scale investigations by use of the 'belt' method. Reasonable accuracy may be obtained by careful use of this method" (p. 1).
Date: February 1943
Creator: Corson, Blake W., Jr.
Partner: UNT Libraries Government Documents Department
open access

The Effect of High Temperature of the Cylinder Head on the Knocking Tendency of an Air-Cooled Engine Cylinder

Description: Report presenting the results of tests to determine the extent to which the knocking tendency of an air-cooled engine cylinder is increased when the cylinder head is poorly cooled and when the cylinder temperature exceeds the maximum specified by the engine manufacturer. The tests showed that, when the cylinder-head temperature was increase from 400 to 600 degrees Fahrenheit, the knock-limited indicated mean effective pressure was reduced 3 percent at a fuel-air ratio of 0.097 and 39 percent at… more
Date: February 1945
Creator: Sanders, J. C. & Peters, M. D.
Partner: UNT Libraries Government Documents Department
open access

Small-orifice tubes for minimizing dilution in exhaust-gas samples

Description: Report presenting an investigation to find a means of obtaining undiluted exhaust-gas samples from a Wright R-2600-B aircraft engine equipped with short individual stacks. Preliminary tests to aid in determining the best design, location, and orientation of orifices ranging in size. Results regarding the Briggs & Stratton engine tests and Wright aircraft engine tests are provided.
Date: February 1943
Creator: Cook, Harvey A. & Olson, Walter T.
Partner: UNT Libraries Government Documents Department
open access

Flame-visibility tests with individual exhaust stacks

Description: Report presenting testing made on a Wright 1820-G single-cylinder engine to determine the effect of operating variables and the effect of shape and size of the exhaust stack on the visibility of exhaust gases for individual-stack installations. Flame damping was improved by decrease in nozzle-exit area, increase in stack length, and reduction in hydraulic diameter of the exhaust jets. Results regarding the characteristics of exhaust flames and damping of exhaust flames are provided.
Date: February 1944
Creator: Turner, L. Richard & Humble, Leroy V.
Partner: UNT Libraries Government Documents Department
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Principles and Methods of Rating and Testing Centrifugal Superchargers

Description: "A discussion of the general principles involved in the rating and testing of centrifugal superchargers, a statement and discussion of present standard methods in rating and testing, and reasons for the adoption of these standards are given" (p. 1).
Date: February 1942
Creator: Ellerbrock, Herman H., Jr. & Goldstein, Arthur W.
Partner: UNT Libraries Government Documents Department
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An Electron-Diffraction Examination of Cast-Iron Piston Rings From Single-Cylinder Aircraft Engine Tests

Description: Report presenting an electron-diffraction examination of cast-iron piston rings used in a single-cylinder test engine, which showed the presence of a layer of graphite covering the surface. The wear curves from the rings studied had shown variation from high rates to very low rates of wear.
Date: February 1945
Creator: Nowick, A. S. & Brockway, L. O.
Partner: UNT Libraries Government Documents Department
open access

Wind-Tunnel Investigation of Carburetor-Air Inlets

Description: Report presenting an investigation of the internal and external airflow characteristics of carburetor-air inlets for liquid-cooled engine installations in the full-scale wind tunnel. Full-scale models of two representative pursuit airplanes were used in the investigation of nine carburetor-air inlets differing in shape, size, and location. Results regarding air flow and ram, drag, and compressibility are provided.
Date: February 1942
Creator: Nelson, W. J. & Czarnecki, K. R.
Partner: UNT Libraries Government Documents Department
open access

Cooling of a Double-Row Radial Engine by Water Injection to the Individual Cylinders

Description: "An injection system that supplies water to each cylinder of a double-row radial engine was tested...as part of a general investigation of the power-plant installation of a four-engine heavy bomber. The tests were conducted to determine the effectiveness of water injection in cooling the engine during take-off. The injection of 500 pounds of water at the take-off power condition reduced the maximum measured exhaust-valve-seat temperature 64 degrees Fahrenheit and the maximum spark-plug-gasket t… more
Date: February 1945
Creator: Monroe, Louis L. & Friedman, Harold E.
Partner: UNT Libraries Government Documents Department
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