National Advisory Committee for Aeronautics (NACA) - 1,437 Matching Results

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Lecture on Aerodynamics

Description: This lecture deals with four main subjects: methods of studying air resistance, experimental aerodynamics, propellers and stability of airplanes.
Date: September 1923
Creator: Toussaint, A
Partner: UNT Libraries Government Documents Department

Static longitudinal stability of "Ente" airplanes

Description: The stability conditions of Ente (duck) airplanes are investigated in this report. In developing the formulas, which afford an approximate solution, the unimportant effect of the height of the C.G. and the moment of the residual resistance are neglected. The effect of downwash from the forward horizontal empennage on the wing are also disregarded.
Date: March 1931
Creator: Kiel, Heinrich Georg
Partner: UNT Libraries Government Documents Department

Drag measurements on a Junkers wing section : application of the Betz Method to the results of comparative tests made on a model and on an airplane in flight

Description: The comparison of model tests in flight can be based on the result of such measurements. They are very important from the aerodynamical point of view, as they lead to useful conclusions regarding the behavior of the wing, its best shape and the conformity of theoretical and actual flow. Although there still remains a certain prejudice against such measurements, I have still attempted to make these comparative tests in order to inspire confidence in their reliability.
Date: September 1927
Creator: Weidinger, Hanns
Partner: UNT Libraries Government Documents Department

Some new tests at the Gottingen laboratory

Description: The tests at the Gottingen laboratory included: friction tests on a surface treated with omelette, verification tests on the M.V.A. 356 wing, and comparative tests of wing no. 36 at the Eiffel laboratory. The examination of all these experiments leads to the belief that, at large incidences, the speeds registered by the suction manometer of the testing chamber of the Eiffel laboratory wind tunnel are, owing to pressure drop, greater than the actual speeds. Therefore, the values of k(sub x) and k(sub y) measured at the Eiffel laboratory at large incidences are too low.
Date: April 1, 1921
Partner: UNT Libraries Government Documents Department

Motion of spheres in still fluids

Description: The behavior of a liquid or gaseous medium, in which a solid body can move freely under the action of a force of constant magnitude and direction, is yet little known.
Date: April 1, 1924
Creator: Hirsch, P
Partner: UNT Libraries Government Documents Department

The vortex theory and its significance in aviation

Description: This report will present ideas closely related to the vortex conception and illustrate them in the simplest possible terms. In addition to these general considerations, this report will attempt to show the application of the vortex theory in connection with the wing theory.
Date: July 1930
Creator: Betz, A.
Partner: UNT Libraries Government Documents Department

Problems concerning the stability and maneuverability of airplanes

Description: The stability of an airplane can be easily determined by wind-tunnel tests, especially by simple tests with models mounted wind-vane fashion. However, each stability curve plotted by this method is valid only for a certain setting of the corresponding control surface, i.e., it characterizes the stability of the airplane with the control stick in a given position. The problems thus defined are studied from the point of view of longitudinal and transverse stability. Directional stability is not included in this study.
Date: March 1, 1932
Creator: Biche, Jean
Partner: UNT Libraries Government Documents Department

The transference of heat from a hot plate to an air stream

Description: The object of the present study was to define experimentally the field of temperature and velocity in a heated flat plate when exposed to an air stream whose direction is parallel to it, then calculate therefrom the heat transference and the friction past the flat plate, and lastly, compare the test data with the mathematical theory. To ensure comparable results, we were to actually obtain or else approximate: a) two-dimensional flow; b) constant plate temperature in the direction of the stream. To approximate the flow in two dimensions, we chose a relatively wide plate and measured the velocity and temperature in the median plane.
Date: April 1931
Creator: Elias, Franz
Partner: UNT Libraries Government Documents Department

Recent developments in the construction and operation of all-metal airplanes

Description: Experiments on the effect of atmosphere and of sea water on the building materials employed by us have been carried on for years in the North Sea with the aid of the Hamburg Naval Observatory. Parallel experiments are being made at the Pisa Naval Observatory in the Mediterranean Sea. Metal sheets, sections, assemblies and experimental floats are being exposed to the action of the elements. Different construction techniques are discussed and a variety of specific airplanes are presented which incorporate some of the new thinking.
Date: September 1, 1926
Creator: Dornier, C
Partner: UNT Libraries Government Documents Department

Clerget 100 hp heavy-oil engine

Description: A complete technical description of the Clerget heavy-oil engine is presented along with the general characteristics. The general characteristics are: 9 cylinders, bore 120 mm, stroke 130 mm, four-stroke cycle engine, rated power limited to 100 hp at 1800 rpm; weight 228 kg; propeller with direct drive and air cooling. Moving parts, engine block, and lubrication are all presented.
Date: January 1, 1931
Creator: Leglise, Pierre
Partner: UNT Libraries Government Documents Department

Combustion of liquid fuels in diesel engine

Description: Hitherto, definite specifications have always been made for fuel oils and they have been classified as more or less good or non-utilizable. The present aim, however, is to build Diesel engines capable of using even the poorest liquid fuels and especially the waste products of the oil industry, without special chemical or physical preparation.
Date: October 1, 1924
Creator: Alt, Otto
Partner: UNT Libraries Government Documents Department

Development of light and small airplanes

Description: The author has endeavored to select only the most important lines of development and has limited the description of individual airplanes to a few typical examples. Comparisons are presented between German and foreign accomplishments.
Date: July 1926
Creator: Lachmann, G
Partner: UNT Libraries Government Documents Department

Accurate calculation of multispar cantilever and semicantilever wings with parallel webs under direct and indirect loading

Description: In the present report the computation is actually carried through for the case of parallel spars of equal resistance in bending without direct loading, including plotting of the influence lines; for other cases the method of calculation is explained. The development of large size airplanes can be speeded up by accurate methods of calculation such as this.
Date: March 1932
Creator: Sanger, Eugen
Partner: UNT Libraries Government Documents Department

Measuring vibration and torque with the oscillograph

Description: The recent development of technical science demands maximum reliability of functioning, together with maximum utilization of construction materials. For this purpose we must know what stresses are produced during functioning. One cause of great stresses are mechanical vibrations and this report describes a method of using an oscilloscope to measure the stresses of rapidly changing phenomena.
Date: December 1, 1924
Creator: Elsasser, R
Partner: UNT Libraries Government Documents Department

Contribution to the systematic investigation on Joukowsky profiles

Description: This article resulted from the need of showing, in a simple way, how the aerodynamic properties of airfoils are affected by the shape of their profiles. No general solution of this problem could be found, since the profile shapes cannot ordinarily be expressed by simple mathematical formulas. This advantage is possessed only by the Joukowsky profiles and this discussion of the problem is therefore limited to them.
Date: April 1, 1928
Creator: Loew, Gottfried
Partner: UNT Libraries Government Documents Department

A few more mechanical-flight formulas without the aid of polar diagrams

Description: The reliability of the assumption of a parabolic shape of the polar curve is investigated and found satisfactory for all practical purposes. It is further shown that the aerodynamically best possible or "ideal" airplane is produced on this assumption. Lastly, detailed suggestions are given on the possibilities of application of this method of calculation. It especially simplifies the design and evaluation of structural changes and the determination of the limits of technical possibilities. The present report deals only with the relations of the airfoils. The mutual action of the airfoils, engine and propeller will be treated in a subsequent report.
Date: March 1, 1928
Creator: Schrenk, Martin
Partner: UNT Libraries Government Documents Department

Atomization of liquid fuels. Part III

Description: This report provides a critical discussion of the results of the experiments conducted in the previous NACA-TM's 329 and 330. The main object of this investigation was to determine the size of the drops in mechanical atomization.
Date: September 1925
Creator: Kuehn, R
Partner: UNT Libraries Government Documents Department

Kinetographic determination of airplane flight characteristics

Description: The author's first experiments with a glider on flight characteristics demonstrated that an accurate flight-path measurement would enable determination of the polar diagram from a gliding flight. Since then he has endeavored to obtain accurate flight measurements by means of kinetograph (motion-picture camera). Different methods of accomplishing this are presented.
Date: April 1927
Creator: Raethjen, P & Knott, H
Partner: UNT Libraries Government Documents Department