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Behavior of Turbulent Boundary Layers on Curved Convex Walls

Description: The system of linear differential equations which indicated the approach of separation and the so-called "boundary-layer thickness" by Gruschwitz is extended in this report to include the case where the friction layer is subject to centrifugal forces. Evaluation of the data yields a strong functional dependence of the momentum change and wall drag on the boundary-layer thickness radius of curvature ratio for the wall. It is further shown that the transition from laminar to turbulent flow occurs… more
Date: April 1936
Creator: Schmidbauer, Hans
open access

Bending of Beams of Thin Sections

Description: The tendency toward economy of material and lightness of structure has long since led to the increased application of beams having large ratios of moment of area W to cross-sectional area F. This paper tries to provide an answer to how thin the beams can be.
Date: April 1936
Creator: Huber, Maximilian T.
open access

General instability criterion of laminar velocity distributions

Description: The present paper describes the results of a stability investigation on symmetrical velocity profiles in a channel and of boundary-layer profiles. The effect of friction was assumed to be vanishing and did not occur in the stability consideration so far as it had been resorted to for preparatory asymptotic considerations. Proceeding on very general premises as regards the form of the velocity distribution, a proof was deduced of the elementary theorem that velocity profiles with inflection poin… more
Date: April 1936
Creator: Tollmien, W.
open access

Influence of Fuel-Oil Temperature on the Combustion in a Prechamber Compression-Ignition Engine

Description: Note presenting the influence of fuel-oil temperature on combustion as investigated by injecting the fuel into the prechamber of a single-cylinder, 4-stroke-cycle, water-cooled, compression-ignition engine operating at 1500 rpm and at a compression ratio of 13.5. The results showed that heating the fuel oil to 750 degrees Fahrenheit increased the injection period, changed the rate of injection, and eliminated the spray cone.
Date: April 1936
Creator: Gerrish, Harold C. & Ayer, Bruce E.
open access

Procedure for determining speed and climbing performance of airships

Description: From Summary: "The procedure for obtaining air-speed and rate-of-climb measurements in performance tests of airships is described. Two methods of obtaining speed measurements, one by means of instruments in the airship and the other by flight over a measured ground course, are explained. Instruments, their calibrations, necessary correction factors, observations, and calculations are detailed for each method, and also for the rate-of-climb tests. A method of correction for the effect on density… more
Date: April 1936
Creator: Thompson, F. L.
open access

Tank tests of models of floats for single-float seaplanes - First series

Description: "Large models of the Mark V and Mark VI floats used for single float seaplanes (National Advisory Committee for Aeronautics (NACA) models 41-A and 41-B, respectively) were tested in the NACA tank to provide general test data for typical single floats and a basis for possible improvements of their form. The resistance of model 41-B was greater than that of model 41-A, either when free to trim or at the best trim angle for each. The resistance of model 35-B (a pointed step hull tested free to tri… more
Date: April 1936
Creator: Parkinson, J. B.
open access

Measurements of fuel distribution within sprays for fuel-injection engines

Description: Two methods were used to measure fuel distribution within sprays from several types of fuel-injection nozzles. A small tube inserted through the wall of an air tight chamber into which the sprays were injected could be moved about inside the chamber. When the pressure was raised to obtain air densities of 6 and 14 atmospheres, some air was forced through the tube and the fuel that was carried with it was separated by absorbent cotton and weighed. Cross sections of sprays from plain, pintle, mul… more
Date: April 8, 1936
Creator: Lee, Dana W.
open access

The effect of lateral controls in producing motion of an airplane as computed from wind-tunnel data

Description: This report presents the results of an analytical study of the lateral controllability of an airplane in which both the static rolling and yawing moments supplied by the controls and the reactions due to the inherent stability of the airplane have been taken into account. The investigation was undertaken partly for the purpose of coordinating the results of a long series of wind-tunnel investigations with phenomena observed in flight tests; for this reason a hypothetical average airplane, embod… more
Date: April 20, 1936
Creator: Weick, Fred E. & Jones, Robert T.
open access

Wing-nacelle-propeller interference for wings of various spans force and pressure-distribution tests

Description: Report presents the results of an experimental investigation made in the NACA full-scale wind tunnel to determine the effect of wing span on nacelle-propeller characteristics and, reciprocally, the lateral extent of nacelle and propeller influence on a monoplane wing. The results provide a check on the validity of the previous research on nacelles and propellers with 15-foot-span wings tested in the 20-foot wind tunnel and reported in technical reports 415, 462, 505, 506, and 507.
Date: April 21, 1936
Creator: Robinson, Russell G. & Herrnstein, William H., Jr.
open access

The quiescent-chamber type compression-ignition engine

Description: Report presents the results of performance tests of a single-cylinder 4-stroke-cycle compression-ignition engine having a vertical disk form of combustion chamber without air flow. The number, size, and direction of the orifices of the fuel-injection nozzles used were independently varied. A table and graphs are presented showing the performance of the engine with different nozzles; results of tests at different compression ratios, boost pressures, and coolant temperatures are also included.
Date: April 30, 1936
Creator: Foster, H. H.
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