Abstract: Systems and devices for controlling flow of a fluid through a valve are provided. A valve plug can include a hub. The hub can include a hub body having a longitudinal axis extending through the hub body and a bore extending along the longitudinal axis extending through the hub body. The hub can also include at least one elliptically-shaped protrusion integrally formed within the hub body. The valve plug can also include a dome having a first surface, a second surface opposite the first surface, and at least one side wall extending between the first surface and the second surface around a circumference of the dome. The valve plug can also include at least one arm extending between the hub body and the second surface of the dome. The valve plug can be coupled to a drive shaft and a controller in a variety of non-limiting valve types.

Abstract: Propulsion system (2) for a helicopter (1) comprising a main engine (9), a main rotor (3), a main gearbox (4) including an output mechanically connected to the main rotor (3), a reduction gearbox (13) mechanically coupled between the main engine (9) and a first input of the main gearbox (4), and an assistance device (10). The assistance device (10) comprises a first electric machine mechanically coupled to the reduction gearbox (13) and configured to operate as an electric generator to take off energy produced by the main engine (9), and a second electric machine mechanically coupled to a second input of the main gearbox (4), the second electric machine being supplied with electrical power by the first electric machine and configured to operate as an electric motor to deliver additional mechanical power to the main gearbox (4).

Abstract: A method for electrohydraulic forming a material blank includes: a material blank to be shaped is placed between a mould and a blank holder; a tight cavity containing electrodes is filled with liquid up to a predetermined liquid level; the material blank is brought into contact with the liquid of the cavity; the material blank is hydraulically preformed; and the material blank is electrohydraulically formed. The liquid of the cavity is pressurised for the hydraulic preforming by moving all or part of one of the walls of the cavity.

Abstract: A method for electrohydraulic forming a material blank includes: a material blank to be shaped is placed between a mould and a blank holder; a tight cavity containing electrodes is filled with liquid up to a predetermined liquid level; the material blank is brought into contact with the liquid of the cavity; the material blank is hydraulically preformed; and the material blank is electrohydraulically formed. The liquid of the cavity is pressurised for the hydraulic preforming by moving all or part of one of the walls of the cavity.