Serial/Series Title
Country
Year
Month
4,107 Matching Results
Results open in a new window/tab.
Results:
1 - 24 of
4,107
next
Notes on Longitudinal Stability and Balance
Report detailing studies of longitudinal stability and balance on five airplanes: the JN4H, DH4, VE7, USAC-11, and Martin Transport. The methods of measurement, methods of correcting instability, and potential modifications for the elevator of the planes is described.
Date:
April 1920
Creator:
Warner, E. P.
System:
The UNT Digital Library
Airplane Performance as Influenced by the Use of a Supercharged Engine
"The question of the influence of a supercharged engine on airplane performance is treated here in a first approximation, but one that gives an exact idea of the advantage of supercharging. Considered here is an airplane that climbs first with an ordinary engine, not supercharged, and afterwards climbs with a supercharged engine. The aim is to find the difference of the ceilings reached in the two cases" (p. 1).
Date:
May 1920
Creator:
de Bothezat, George
System:
The UNT Digital Library
Notes on the Theory of the Accelerometer
Report discusses several types of accelerometers and how they function. Methods for reducing error and determining the source of the error, including the best placement for the device, are included.
Date:
May 1920
Creator:
Warner, E. P.
System:
The UNT Digital Library
The Problem of the Helicopter
Report discussing some of the issues regarding the design and operation of helicopters and the theoretical basis behind them. Some particular issues covered include propeller blade design, helicopters in forced descent, horizontal travel, and stability and control.
Date:
May 1920
Creator:
Warner, E. P.
System:
The UNT Digital Library
Relation of Rib Spacing to Stress in Wing Planes
The stress relations to the fabric and the rib consequent upon a change of spacing between ribs in a wing plane are discussed. Considering the wing plane as a static structure, and ignoring the question of aerodynamic efficiency, it appears that the unit stress in the rib and fabric will remain constant for constant p if the linear dimensions of both rib and fabric are increased alike, viz., if wing and fabric remain geometrically similar. Since the bulge and the structural dimensions remain geometrically similar, the whole distended plane remains so, and hence should have the same pressure distribution and efficiency.
Date:
May 1920
Creator:
Zahm, A. F.
System:
The UNT Digital Library
Duralumin
Various properties of duralumin as used in aircraft construction are discussed, including the effects of temperature, working, tempering, and strength.
Date:
July 1920
Creator:
Unger, E. & Schmidt, E.
System:
The UNT Digital Library
Notes on the Design of Supercharged and Over-dimensioned Aircraft Engines
The author discusses the limited benefits of supercharging motors and some of the factors that make supercharging less beneficial than it initially appears.
Date:
July 1920
Creator:
Schwager, [Otto]
System:
The UNT Digital Library
Static Testing and Proposed Standard Specifications
Static tests fall into two groups, the first of which is designed to load all members of the structure approximately in accordance with the worst loads which they carry in flight, while the second is directed to the testing of specific members which are suspected of weakness and which are difficult to analyze mathematically. The nature of the loading in the second type is different for every different test, but the purpose of the first is defined clearly enough to permit the adoption of some standard set of loading specifications, at least for airplanes of normal design. Here, an attempt is made to carry through an analysis leading to such a standard, the goal being the determination of a load which will simultaneously impose on every member of the airplane structure a stress equal to the worst it will carry in flight.
Date:
July 1920
Creator:
Warner, E. P.
System:
The UNT Digital Library
Theory of Lifting Surfaces
The general basis of the theory of lifting surfaces is discussed. The problem of the flow of a fluid about a lifting surface of infinite span is examined in terms of the existence of vortexes in the current. A general theory of permanent flow is discussed. Formulas for determining the influence of aspect ratio that may be applied to all wings, whatever their plane form, are given.
Date:
July 1920
Creator:
Prandtl, L.
System:
The UNT Digital Library
Increase in Maximum Pressures Produced by Preignition in Internal Combustion Engines
Report discusses the calculations that can be used to show why pressures inside an engine during preignition are higher than average. This information can be used to design a safer engine that is able to contain the increased pressure and heat generated during preignition.
Date:
August 1920
Creator:
Sparrow, S. W.
System:
The UNT Digital Library
The Problem of the Turbo-Compressor
"In terminating the study of the adaptation of the engine to the airplane, we will examine the problem of the turbo-compressor, the first realization of which dates from the war; this will form an addition to the indications already given on supercharging at various altitudes. This subject is of great importance for the application of the turbo-compressor worked by the exhaust gases. Assuming that the increase of pressure in the admission manifold is the same in both cases, the pressure in the exhaust manifold would be greater in the case in which the compressor is worked by the exhaust gas and there would result a certain reduction of engine power which we must be able to calculate" (p. 1).
Date:
August 1920
Creator:
Devillers, René
System:
The UNT Digital Library
Soaring Flight in Guinea
Report discusses information obtained from studying large birds that fly by soaring, which involves using the wind without moving their wings. An Egyptian vulture and African white-backed vulture were observed and their relative air speed, upward air velocity, lift, and drag were noted. The experimental methods for measuring these values are described.
Date:
August 1920
Creator:
Idrac, Pierre
System:
The UNT Digital Library
Theory of Lifting Surfaces, Part 2
A mathematical model is presented towards a theory of lifting and resistance on wings. It consists hide of a theory of multiplanes, conditions of flow at a great distance from the wing, lifting systems of minimum resistance, and free stream and stream limited by walls.
Date:
August 1920
Creator:
Prandtl, L.
System:
The UNT Digital Library
Drag or Negative Traction of Geared-Down Supporting Propellers in the Downward Vertical Glide of a Helicopter
Discussed here are computations of drag or negative traction of geared down supporting propellers in the downward vertical glide of a helicopter. By means of Frounde's Theory, the maximum value of the drag of a windmill is calculated. For wooden propellers, the author finds that the difference between the drag and the weight is proportional to the number of blades and is larger for propellers of small diameter; thus it is 25 kg. for a six blade propeller with a diameter of 2 m. 50.
Date:
September 1920
Creator:
Toussaint, A.
System:
The UNT Digital Library
The Dynamometer Hub
The construction of the dynamometer hub is illustrated and explained, and its electrical and aviation motor tests, as well as those in free flight, described.
Date:
September 1920
Creator:
Stieber, W.
System:
The UNT Digital Library
Experience With Geared Propeller Drives for Aviation Engines
An overview is given of experience with geared propeller drives for aviation engines. The development of gear wheels is discussed with emphasis upon bending stresses, compressive stresses, heating, and precision in manufacturing. With respect to the general arrangement of gear drives for airplanes, some principal rules of mechanical engineering that apply with special force are noted.
Date:
September 1920
Creator:
Kutzbach, K.
System:
The UNT Digital Library
Recent Efforts and Experiments in the Construction of Aviation Engines
It became evident during World War I that ever-increasing demands were being placed on the mean power of aircraft engines as a result of the increased on board equipment and the demands of aerial combat. The need was for increased climbing efficiency and climbing speed. The response to these demands has been in terms of lightweight construction and the adaptation of the aircraft engine to the requirements of its use.
Date:
September 1920
Creator:
Schwager, [Otto]
System:
The UNT Digital Library
Notes on Specifications for French Airplane Competitions
Given here are the rules officially adopted by the Aeronautical Commission of the Aero Club of France for a flight competition to be held in France in 1920 at the Villacoublay Aerodrome. The prize will be awarded to the pilot who succeeds in obtaining the highest maximum and lowest minimum speeds, and in landing within the shortest distance.
Date:
October 1920
Creator:
Margoulis, W.
System:
The UNT Digital Library
Tests of the Daimler D-IVa Engine at a High Altitude Test Bench
Reports of tests of a Daimler IVa engine at the test-bench at Friedrichshafen, show that the decrease of power of that engine, at high altitudes, was established, and that the manner of its working when air is supplied at a certain pressure was explained. These tests were preparatory to the installation of compressors in giant aircraft for the purpose of maintaining constant power at high altitudes.
Date:
October 1920
Creator:
Noack, W. G.
System:
The UNT Digital Library
Development of the Inflow Theory of the Propeller
Report discusses the theory of inflow of the propeller and the fact that both suctional axial velocity and suctional tangential velocity must be considered when calculating the maximum efficiency.
Date:
November 1920
Creator:
Betz, A.
System:
The UNT Digital Library
Göttingen Wind Tunnel for Testing Aircraft Models
Given here is a brief description of the Göttingen wind tunnel for the testing of aircraft models, preceded by a history of its development. Included are a number of diagrams illustrating, among other things, a sectional elevation of the wind tunnel, the pressure regulator, the entrance cone and method of supporting a model for simple drag tests, a three-component balance, and a propeller testing device, all of which are discussed in the text.
Date:
November 1920
Creator:
Prandtl, L.
System:
The UNT Digital Library
Horizontal Buoyancy in Wind Tunnels
Note presenting an examination of horizontal buoyancy in wind tunnels, including an examination of the relative flow, static pressure gradient, horizontal buoyancy computation, and methods of computation in practical use are provided.
Date:
November 1920
Creator:
Zahm, A. F.
System:
The UNT Digital Library
Italian and French Experiments on Wind Tunnels
Given here are the results of experiments conducted by Colonel Costanzi of the Italian Army to determine the influence of the surrounding building in which a wind tunnel was installed on the efficiency of the installation, and how the efficiency of the installation was affected by the design of the tunnel. Also given are the results of a series of experiments by Eiffel on 34 models of tunnels of different dimensions. This series of experiments was started in order to find out if, by changing the shape of the nozzle or of the diffuser of the large tunnel at Auteuil, the efficiency of the installation could be improved.
Date:
November 1920
Creator:
Knight, William
System:
The UNT Digital Library
The Photographic Recording of Small Motions
Methods and equipment for recording small and sometimes rapid motions by photographic means are described, and the efficacy of photographic recording in such instances is evaluated. The optical system consisting of the light source, the mirror or prism for transmitting motion to the emergent beam, and a means of bringing the rays into focus on the film are discussed. Attention is given to the critical issue of mirror mounting.
Date:
November 1920
Creator:
Norton, F. H.
System:
The UNT Digital Library