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Margoulis, W

Publications and source records attributed to Margoulis, W.

Joukowski wings

To sum up, Professor Joukowski's theory of supporting wings renders it possible to calculate the coefficient of lift in terms of the angle of attack, and Prandtl's coefficient of induced drag and the correction of the angle of attack in terms of the disposition and aspect ratio of the wings.

AIRFOILS - JOUKOWSKI - CHAR

Propeller theory of Professor Joukowski and his pupils

This report gives a summary of the work done in Russia from 1911 to 1914, by Professor Joukowski and his pupils. This summary will show that these men were the true originators of the theory, which combines the theory of the wing element and of the slipstream.

PROPELLERS - THEORY

A New Method of Testing in Wind Tunnels

Now, in existing wind tunnels, using a horsepower of 100 to 300, the models are generally made to a 1/10 scale and the speed is appreciably lower than the speeds currently attained by airplanes. The Reynolds number realized is thus 15 to 25 times smaller than that reached by airplanes in free flight, while the ratio of speed to the velocity of sound is between a third and three quarters of the true ratio. The necessary increases in either the diameter of the wind tunnel or the velocity of the airstream are too costly. However, the author shows that it is possible to have wind tunnels in which the Reynolds number will be greater than that now obtained by airplanes, and in which the ratio of the velocity to the velocity of sound will also be greater than that realized in practice, by employing a gas other than air, at a pressure and temperature different from those of the surrounding atmosphere. The gas is carbonic acid, a gas having a low coefficient of viscosity, high density, and a low ratio of specific heat. The positive results of using carbonic acid in wind tunnel tests are given.

Margoulis, W

Gordon Bennett Airplane Cup

The characteristics of the airplanes built for the Gordon Bennet Airplane Cup race that took place on September 28, 1920 are described. The airplanes are discussed from a aerodynamical point of view, with a number of new details concerning the French machines. Also discussed is the regulation of future races. The author argues that there should be no limitations on the power of the aircraft engines. He reasons that in the present state of things, liberty with regard to engine power does not lead to a search for the most powerful engine, but for one which is reliable and light, thus leading to progress.

Margoulis, W

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.

Margoulis, W