Search Results

open access

The effect of exhaust-stack shape on the design and performance of the individual cylinder exhaust-gas jet-propulsion system

Description: Report presenting tests on a single-cylinder, air-cooled engine to determine the effect of several different exhaust-stack shapes on the design and performance of the individual cylinder exhaust-gas jet-propulsion systems. Results regarding the effect of nozzle area and stack shape on exhaust-gas jet thrust, effect of nozzle area and stack shape on overall performance for the S-shape, the 90 degree bend, and the 180 degree bend, the effect on the shape on engine power and volumetric efficiency,… more
Date: November 1942
Creator: Turner, L. Richard & Humble, Leroy V.
open access

Full-Scale Tunnel Investigation of the Control and Stability of a Twin-Engine Monoplane With Propellers Operating

Description: Report presenting extensive force tests covering a wide range of propeller thrust coefficients on a typical twin-engine tractor monoplane model with the horizontal tail surface removed and attached. Measurements were made with flaps retracted and deflected at various angles of attack with different stabilizer and elevator settings. Results regarding the effect of propeller operation on wing-fuselage combination and forces and air flow at tail are provided.
Date: November 1942
Creator: Sweberg, Harold H.
open access

Control-Motion Studies of the PBM-3 Flying Boat in Abrupt Pull-Ups

Description: Report presenting a control-motion study in flight that is part of series covering a range of types and sizes of modern airplanes. This particular one involves the PBM-3 flying boat, which is equipped with a control mechanism typical of the cable-type systems in large transport, cargo, or bomber airplanes as well as those employed in flying boats. The elasticity of the elevator control system of the PBM-3 was such to limit the obtainable acceleration to about 3g for center-of-gravity positions … more
Date: November 1942
Creator: Pearson, Henry A. & Smull, Leland K.
open access

Comparison of Intercooler Characteristics

Description: Report presenting a method of comparing the performance, weight, and general dimensional characteristics of intercoolers. The performance and dimensional characteristics covered in the comparisons include cooling effectiveness, pressure drops and weight flows of the charge and cooling air, power losses, volume, frontal area, and width.
Date: November 1942
Creator: Reuter, J. George & Valerino, Michael F.
open access

Cooling Investigation of a B-24D Engine-Nacelle Installation in the NACA Full-Scale Tunnel

Description: Report presenting an investigation conducted in the full-scale tunnel to determine methods of improving the cooling of the B-24D engine installation. The B-24D is a four-engine high-wing monoplane having a span of 110 feet, a wing area of 1048 square feet, and a gross weight of 56,000 pounds.
Date: November 1942
Creator: Lehr, Robert R.; Kinghorn, George F. & Guryansky, Eugene R.
open access

Stability of elastically supported columns

Description: A criterion is developed for the stiffness required of elastic lateral supports at the ends of a compression member to provide stability. A method based on this criterion is then developed for checking the stability of a continuous beam-column. A related method is also developed for checking the stability of a member of a pin-jointed truss against rotation in the plane of the truss.
Date: November 1942
Creator: Niles, Alfred S. & Viscovich, Steven J.
open access

Bending tests of a monocoque box

Description: A monocoque box beam consisting of a 24S-T aluminum-alloy sheet reinforced by four bulkheads and by longitudinal stringers and corner posts was subjected to bending loads as follows: pure bending about the lift axis, cantilever bending about the lift axis, and pure bending about both lift and drag axis. Longitudinal strains were measured for loads up to a load at which permanent set became measurable. The loads were sufficient to produce buckling of the sheet between stringers on the compressio… more
Date: November 1942
Creator: McPherson, Albert E.; Ramberg, Walter & Levy, Samuel
open access

Torsion Tests of a Monocoque Box

Description: Report presenting testing of a monocoque box of aluminum alloy, which had torques applied to the ends. The twist, strain in the stringers, plate, and corner posts, and the buckling load were measured. A new analysis was developed for the twisting of a monocoque box reinforced by stringers, corner posts, and bulkheads, and the measured twist agreed within 10 percent of the analytical value.
Date: November 1942
Creator: Levy, Samuel; McPherson, Albert E. & Ramberg, Walter
open access

A study of general instability of box beams with truss-type ribs

Description: The design of truss-type ribs for box beams is theoretically treated with regard to the function of the ribs in stabilizing the compression flange. The theory is applied to a design problem, and the results of this application are presented and discussed in relation to the general problem of rib design. The results of some tests made as a part of this general study are presented in an appendix.
Date: November 1942
Creator: Lundquist, Eugene E. & Schwartz, Edward B.
open access

Summary of Results of Tests Made by Aluminum Research Laboratories of Spot-Welded Joints and Structural Elements

Description: "Available information concerning spot welding as a means of joining aluminum-alloy parts has been summarized and comparisons have been made of the relative merits of spot-welded and riveted aluminum-alloy structural elements. The results indicated that spot welding was as satisfactory as riveting insofar as resistance to static loads is concerned. Spot welds showed slightly lower resistance to impact loads but definitely lower resistance to repeated loads than rivets" (p. 1).
Date: November 1942
Creator: Hartmann, E. C. & Stickley, G. W.
open access

A Profile-Drag Investigation in Flight on an Experimental Fighter-Type Airplane the North American XP-51

Description: Report discussing the results of an investigation of the North American XP-51 and its low-drag airfoils. Several surface conditions were tested and the profile-drag coefficients were determined. The surface that was smoothened and faired by filling and sanding had the lowest profile-drag coefficient.
Date: November 1942
Creator: Zalovcik, John A.
open access

Derivation of charts for determining the horizontal tail load variation with any elevator motion

Description: From Summary: "The equations relating the wing and tail loads are derived for a unit elevator displacement. These equations are then converted into a nondimensional form and charts are given by which the wing- and tail-load-increment variation may be determined under dynamic conditions for any type of elevator motion and for various degrees of airplane stability. In order to illustrate the use of the charts, several examples are included in which the wing and tail loads are evaluated for a numb… more
Date: November 23, 1942
Creator: Pearson, Henry A.
open access

Identification of knock in NACA high-speed photographs of combustion in a spark-ignition engine

Description: Report presents the results of a study of combustion in a spark-ignition engine given in NACA Technical Reports 704 and 727. The present investigation was made with the NACA high-speed motion-picture camera, operating at 40,000 photographs a second, and with a cathode-ray oscillograph operating on a piezoelectric pick-up in the combustion chamber. Photographs are presented showing that the origin of knock is not necessarily in the end gas. The data obtained indicates that knock takes place only… more
Date: November 14, 1942
Creator: Miller, Cearcy D. & Olsen, H. Lowell
open access

Flight investigation of an NACA ice-detector suitable for use as a rate-of-icing indicator

Description: Report presenting an ice detector that can serve as a basis for a rate-of-icing indicator. The instrument consists of a wire screen and a pitot tube mounted behind the screen with both enclosed in a cylindrical shell. Observed data and some possibilities for future development are provided.
Date: November 1942
Creator: Gilruth, R. R.; Zalovcik, J. A. & Jones, A. R.
open access

Interference effects of longitudinal flat plates on low-drag airfoils

Description: Three airfoils were tested with an intersecting flat plate normal to the span as a preliminary study of interference effects on airfoils. Small interference effects were noted on the first two airfoils, while larger effects were noted on the NACA 66,2-422 section, which had previously been shown to be unconservative with respect to separation. Airfoils known to be conservative should be used for inboard sections subject to nacelle and fuselage interference.
Date: November 1942
Creator: Abbott, Ira H.
open access

Investigation of the Variation of Lift Coefficient With Reynolds Number at a Moderate Angle of Attack on a Low-Drag Airfoil

Description: Bulletin presenting an investigation of the boundary layer about the NACA 66,2-216, a = 0.6 airfoil section in the two-dimensional low-turbulence tunnel. The primary purpose was to find an explanation for the decreased slope of the lift curve observed for some of the low-drag sections outside the low-drag range at low Reynolds numbers.
Date: November 1942
Creator: von Doenhoff, Albert E. & Tetervin, Neal
open access

Lateral-control characteristics of North American XP-51 airplane (A. C. No. 41-38) with beveled trailing-edge ailerons in high-speed flight

Description: Report presenting the flight tests of beveled trailing-edge ailerons on the North American XP-51 airplane which were extended to determine the aileron characteristics in high-speed dives. Standard recording instruments were used to determine airspeed, aileron position, stick force, and rate of roll. The results show that the beveled trailing-edge form of aerodynamic balance had no abnormal or unusual characteristics in high-speed flight.
Date: November 1942
Creator: Hoover, Herbert H. & White, Maurice D.
open access

Full-Scale-Tunnel Investigation of a Multiengine Pusher-Propeller Installation

Description: Report presenting an investigation of propellers designed specifically for pusher operation behind fixed contravanes on a large-scale model of a four-engine airplane. In the test, the wing trailing edge was twisted to serve as a contravane and to produce the rotating inflow required for optimum propulsive efficiency. Results indicated that gains in efficiency of about 3.5 percent at a blade angle of 40 degrees can be obtained by the use of contravanes with specifically designed pusher propeller… more
Date: November 1942
Creator: Wilson, Herbert A., Jr.
open access

Some theoretical considerations of longitudinal stability in power-on flight with special reference to wind-tunnel testing

Description: Report presenting a consideration of some problems related to longitudinal stability in power-on flight. The results indicated that the destabilizing effects of power are more pronounced when the horizontal tail is required to carry a down load to maintain flight equilibrium.
Date: November 1942
Creator: Donlan, Charles J.
open access

Graphical representation of intercooler parameters and performance at altitudes from 25,000 to 60,000 feet

Description: From Summary: "Interdependence of intercooler parameters and performance for a pursuit-type airplane using a 1675-horsepower engine is shown at altitudes of 25,000, 36,000, 47,000, and 60,000 feet by means of perspective drawings. Qualitatively, the drawings have general application. Intercooling between stages of supercharging at high altitudes results in no saving in the power to supercharge and cool the engine air."
Date: November 1942
Creator: Brimley, D. E.
open access

The Longitudinal Stability of Flying Boats as Determined by Tests of Models in the NACA Tank 2: Effect of Variations in Form of Hull on Longitudinal Stability

Description: Data taken from tests at constant speed to establish trim limits of stability, tests at accelerated speeds to determine stable limits of center of gravity shift, and tests at decelerated speeds to obtain landing characteristics of several model hull forms were used to establish hull design effect on longitudinal stability of porpoising. Results show a reduction of dead rise angle as being the only investigated factor reducing low trim limit. Various methods of reducing afterbody interference in… more
Date: November 1942
Creator: Truscott, Starr & Olson, Roland E.
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