UNT Libraries Government Documents Department - 192 Matching Results

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Dependence of Propeller Efficiency on Angle of Attack of Propeller Blade

Description: In order to determine the maximum and the most favorable pitch for a propeller, it was found desirable to investigate the dependence of propeller efficiency on the angle of attack of the propeller blade. The results of a few experiments are given to show that propeller blades conduct themselves just like airplane wings with reference to the dependence of their efficiency on their angle of attack.
Date: December 1921
Creator: Borck, Hermann
Item Type: Refine your search to only Report
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Destructive Distillation of Mixtures of Oil and Coal

Description: Report issued by the U.S. Bureau of Mines on the characteristics and behavior of oil and coal distillation processes. The effectiveness of the distillation processes and the properties of the oil and coal mixtures are presented. This report includes tables, graphs, and illustrations.
Date: December 1921
Creator: Davis, Joseph D.; Place, Palmer B. & Scott, G. S.
Item Type: Refine your search to only Report
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Effects of Varying the Relative Vertical Position of Wing and Fuselage

Description: "The object of this series of experiments was to determine the influence of the relative vertical position of wing and fuselage on the efficiency of the wing. Since the longitudinal position of the wing can be varied but slightly with reference to the center of gravity in a normal airplane, it was kept constant in the experiments to be described and only the vertical position of the wing with reference to the fuselage was varied" (p. 1).
Date: December 1921
Creator: Prandtl, L.
Item Type: Refine your search to only Report
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Ground Influence on Aerofoils

Description: The question of ground influence on airplanes has recently attracted some attention in view of the claims made by certain designers that the landing speed of their airplanes is much decreased by an increase in lift coefficient due to the proximity of the ground in landing. The results of wind tunnel tests indicate that ground effect is not entirely beneficial. It decreases the landing speed and cushions the landing shock somewhat. However, it does so at the expense of an increased length of pre… more
Date: December 1921
Creator: Raymond, Arthur E.
Item Type: Refine your search to only Report
open access

The Choice of Wing Sections for Airplanes

Description: "The subject of the choice of an airfoil section is by no means a closed one, and despite the impossibility of making a single rule serve, it is quite practicable to deduce in a strictly rational manner a series of rules and formulas which are capable of being of the greatest use if we but confine ourselves to the consideration of one element of performance at a time. There are seven such elements of performance which are here taken up in turn. The seven are of different relative importance in … more
Date: November 1921
Creator: Warner, Edward P.
Item Type: Refine your search to only Report
open access

Drying crude drugs.

Description: Explains the fundamental principles of drying crude vegetable drugs. Provides drawings and instructions for constructing two types of driers.
Date: November 1921
Creator: Russell, G. A.
Item Type: Refine your search to only Book
open access

Establishment of Aviation Schools

Description: Report presenting a discussion of the creation of a suitable aviation school and some of the characteristics that should be considered in terms of hiring personnel, creating a curriculum, and obtaining equipment.
Date: November 1921
Creator: Kempe, Erich
Item Type: Refine your search to only Report
open access

An Investigation on the Effect of Raked Wing Tips

Description: This investigation was carried out by request of the United States Air Service in the wind tunnel of the Massachusetts Institute of Technology. The results are here published by the National Advisory Committee for Aeronautics as it is thought that they may be of general interest. Wings of the R.A.F. 6 section are tested with various angles of rake, and it is found that although rake has very little effect, a positive or negative rake of 30 degrees is the best.
Date: November 1921
Creator: Norton, F. H.
Item Type: Refine your search to only Report
open access

Pressure Measurements During Flight

Description: The general idea was to record the air pressure on the spot, that is, without intervening tubes, by some simple automatic registering device. This was therefore made in such small dimensions that it could be inserted into the wing between the ribs and stand in direct connection with the pressure openings. The results of different experiments are presented along with the best locations for locating the instruments for recording the pressure.
Date: November 1921
Creator: Pröll, A.
Item Type: Refine your search to only Report
open access

Vortices and the Related Principles of Hydrodynamics

Description: Here, conceptions concerning vortices are illustrated by the simplest possible examples. Mathematical formulas and similar means of presentation, which, for the most part, do not help the understanding of persons not versed therein, have been avoided as much as possible. Instead, the author has endeavored to demonstrate the phenomena by means of simple geometrical and mechanical illustrations. For the sake of clarity, the author chiefly considers currents in one plane only, a situation that can… more
Date: November 1921
Creator: Betz, A.
Item Type: Refine your search to only Report
open access

A Biological Survey of Alabama

Description: Booklet describing the biology of Alabama in two sections: (1) physiography and life zones, and (2) mammals. It also includes an annotated species list of mammals, bibliography, and index starting on page 81.
Date: October 28, 1921
Creator: Howell, Arthur H.
Item Type: Refine your search to only Report
open access

N.A.C.A. Recording Air Speed Meter

Description: A new type of air speed meter is described which was designed by the technical staff of the National Advisory Committee for Aeronautics. The instrument consists essentially of a tight metal diaphragm of high natural period which is acted upon by the pressure difference of a pitot-static head. The resulting deflection of this diaphragm is recorded optically on a moving film.
Date: October 1921
Creator: Norton, F. H.
Item Type: Refine your search to only Report
open access

Crippling Strength of Axially Loaded Rods

Description: A new empirical formula was developed that holds good for any length and any material of a rod, and agrees well with the results of extensive strength tests. To facilitate calculations, three tables are included, giving the crippling load for solid and hollow sectioned wooden rods of different thickness and length, as well as for steel tubes manufactured according to the standards of Army Air Services Inspection. Further, a graphical method of calculation of the breaking load is derived in whic… more
Date: October 1921
Creator: Natalis, F. & Pawlowski, F. W.
Item Type: Refine your search to only Report
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