Abstract: The fan comprises a volute housing (10) in which is disposed a ventilation wheel (11) connected to a driving motor (12). The wheel has a series of vanes (13) extending in a direction roughly parallel to the axis of rotation (X--X) of the wheel from a bowl (14) connecting the vanes to the driving motor to an edge portion (15) of an air intake (16) defining with the bowl a space for a fluid stream. The confronting surfaces of the bowl and the edge portion of the air intake, at least to the inner edges of the vanes, are generated by rotation of parallel sections of curves about the axis of rotation (X--X).

Abstract: The blade (10) for a propeller constituted by a hub (20) to which the feet (12) are fixed has a leading edge (14) and a trailing edge (15) which is formed by two arcs (152, 153) having respective mean radii of curvature (.rho.2, .rho.3) which are different and interconnected without an angular point. These edges are both curved in the downstream direction and define a blade which narrows from the axis to the periphery of the propeller. Application in propellers of motorized fans associated with automobile vehicles.

Abstract: The proposed technique makes use of a non-deformable sealed tank (10) of specific volume, a pressurized-fluid supply (30) equipped with a connector (31) intended to be connected to an orifice in the hollow component (50), a liquid delivery (20) for filling and emptying the tank, once the component has been submerged in it, and a sensor (40) for detecting the variation in volume of the liquid in the tank resulting from the deformations of the casing of the component which are caused by the set pressure of the fluid prevailing in it. The invention is used to assess the probable emission capacity of components during their design, in particular intake-line of motor-vehicle engines.