Abstract: The device comprises a variable frequency AC generator with means of exitation supplied by means for controlling exitation current, means for regulation of the frequency of the generator as a function of an index value, means for measuring actual speed of the mobile portion of the motor, and means for comparing actual speed with the index value. According to the invention, the means for controlling the exitation current are connected to the means for comparing actual speed with the index value, and the generator has a high internal reactance.

Abstract: A hydrodynamic test apparatus including a model support which comprises a submerged frame equipped with rollers and resting on the bottom of a tank is disclosed. A removable plate is attached to the top of the frame and a linear induction motor is attached to the side of the frame. The linear induction motor is supplied with current by conductor rails affixed to the bottom of the tank.

Abstract: A wheel structure such as a flywheel with hub and rim adapted for use at high angular velocities including a strong, compact and perfectly balanced coiling formed by a radiating winding of at least two cables linking the wheel hub to the wheel rim and enveloping the rim. Also the method of manufacturing of the wheel structure by winding of the cables between the wheel hub and wheel rim by cables continuously dispensed under constant tension looped around the wheel rim.

Abstract: The invention relates to a composite wheel capable of withstanding large centrifugal forces, including at least two elements made of materials with different yield strengths, one of said elements being peripheral and the other element connecting said peripheral element to the wheel hub, characterized in that said element connecting the peripheral element to the hub comprises two conical flanges having their concave sides facing each other, means being provided to vary the angle subtended by the flanges whereby to obtain, as necessary, either a limitation of the stresses exerted on the material forming the flanges (the diameter of the wheel remaining constant and the angle between flanges widening), or an accompaniment by said flanges of the expansion undergone by the peripheral material (the wheel diameter increasing and the inter-flange angle widening or narrowing).