UNT Libraries Government Documents Department - 51 Matching Results

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Aero dopes and varnishes

Description: Report discussing before proceeding to discuss the preparation of dope solutions, it will be necessary to consider some of the essential properties which should be possessed of a dope film, deposited in and on the surface of an aero fabric. The first is that it should tighten the material and second it should withstand weathering.
Date: July 1927
Creator: Britton, H T S

Calculating Thrust Distribution and Efficiency of Air Propellers

Description: I am now proposing a method for the preliminary approximate calculation of the thrust distribution and efficiency of air propellers under any operating conditions. Our task becomes the following, namely, to determine the speed relations and the forces developed on a section with a given direction and velocity of the air current, a problem which can be solved with the aid of the momentum theory.
Date: December 1927
Creator: Bienen, Theodor

Climbing Efficiency of Aircraft

Description: The object of this report was to indicate that we frequently only make use of 50 percent of the maximum brake horsepower of the engine in taking off the ground, that this loss is not inevitable, and that the effort to get engines of low weight per horsepower by boosting revolutions is of very little use to bombers and commercial airplanes.
Date: June 1927
Creator: Walker, C. C.

Determining the Velocity Distribution in the Boundary Layer of an Airfoil Fitted With a Rotary Cylinder

Description: In the closer investigation of the results obtained from a wing model with a rotary cylinder mounted in its leading edge (NACA TM's 307 and 354), the velocity distribution in the vicinity of the surface of the model was determined by a hot-wire anemometer. The results confirmed the belief that the rotary cylinder had considerable effect on the air flow, but demonstrated the fact that the direct influence of the cylinder is confined to a very thin layer in immediate proximity to the surface.
Date: May 1927
Creator: Van der Hegge Zijnen, B. G.

Discussion of the results of the boundary-layer tests of an airfoil fitted with a rotary cylinder

Description: The results of the velocity measurements in the boundary layer described in NACA-TM 411 are here discussed in greater detail. The measurements made were of the velocity distribution in the vicinity of an airfoil model fitted with a rotary cylinder and were undertaken for the purpose of obtaining a closer insight into the phenomena observed in experimenting with this model.
Date: August 1927
Creator: Wolff, E. B. & Koning, C.

Drag measurements of two thin wing sections at different index values

Description: It is stated that the index value 6000, as found in normal tests of wing sections with a 20 cm chord, falls in the same region where the transition of laminar to turbulent flow takes place on thin flat plates. It is to be expected that slightly cambered, thin wing sections will behave similarly. The following test of two such wing sections were made for the purpose of verifying this supposition.
Date: June 1927
Creator: Ackeret, J.

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

Duralumin and Its Corrosion

Description: The types of corrosion and factors of corrosion of duralumin are investigated. Salt water is the most common of the corroding media with which designers have to contend in using duralumin in aircraft and ships.
Date: April 1927
Creator: Nelson, Wm.

Duralumin - Defects and Failures

Description: It is proposed in this paper to identify some of the defects and failures in duralumin most frequently encountered by the aircraft industry with a view to indicate their importance. The defects and failures in duralumin may be classified into the following groups: 1) defects produced during manufacture; 2) defects produced during fabrication; 3) corrosion and erosion; and 4) fatigue failures. Only the first two will be covered in this report.
Date: December 1927
Creator: Nelson, Wm.

Duralumin Welding

Description: Gas and electric welding of duralumin are discussed. Some of the elements that go into determining a successful weld and inspecting for faults are also described.
Date: February 1927
Creator: Nelson, Wm.

Experiments on airfoils with aileron and slot

Description: The present report contains the results of a few experiments on three airfoils to which the rear portions, having chords respectively 1/4, 1/3, and 2/5 of the total chords, are hinged so as to form ailerons, especial attention being given to the shape of the slot between the aileron and the main portion of the aileron.
Date: November 1927
Creator: Betz, A.

Experiments on airfoils with trailing edge cut away

Description: "Airfoils with their trailing edge cut away are often found on aircraft, as the fins on the hulls of flying boats and the central section of the wings for affording better visibility. It was therefore of some interest to discover the effect of such cutaways on the lift and drag and on the position of the center of pressure. For this purpose, systematic experiments were performed on two different airfoils, a symmetrical airfoil and an airfoil of medium thickness, with successive shortenings of their chords" (p. 1).
Date: September 1927
Creator: Ackeret, J.

Experiments With Three Horizontal Empennages

Description: The main objective of these experiments was to determine how the air forces on the whole empennage are affected by varying the size of the elevator without changing the size of the whole empennage. The secondary objective was to determine how the magnitude of the air forces acting on the elevator (or the elevator moments) are affected by varying the angle of attack of the whole empennage, or of the elevator alone.
Date: July 1927
Creator: Seiferth, R.

Glider Construction and Design

Description: The endeavor to draw a strict line between gliders and soarers as been recently abandoned and the following classification adopted: 1) gliders controlled by shifting the weight of the body; 2) gliders controlled by rudders; 3) gliders controlled by wings. The different classes are discussed as well as materials and parts used in construction.
Date: October 1927
Creator: Gymnich, Alfried

"Gloster" High Lift Biplane Wings

Description: "The main object of these wings was to obtain a high lift without increasing the total drag, and the idea was conceived that, by using a deep high-lift section for the top wing and a medium section for the bottom wing, the mutual interference between the two would be such as to give greater efficiency of the combination as compared with two wings of equal section" (p. 1).
Date: December 1927
Creator: Preston, H. E.