Magnetohydrodynamic inertial actuator

An inertial actuator for stabilising and/or aiming a platform along a predetermined direction comprising:

• a fluid ring, of a torus shape, including a central ring hole crossed by a central axis, having an internal size equal to the diameter of the ring hole, filled with a conductive liquid and having at least one air gap area, capable of being crossed by magnetic field(s) and having at least one effective area for setting the liquid into motion, and
• at least one magnetohydrodynamic pump for setting the conductive liquid into motion around the central axis of the fluid ring,
• each magnetohydrodynamic pump having a single and different air gap, the air gap being associated with a single and different air gap area and with effective areas for setting into motion included in the air gap area,
• each magnetohydrodynamic pump including a single and different means for generating magnetic field(s) crossing the associated air gap, and including at least one single and different magnetic conduction element, configured for conducting and channelling the magnetic field(s) generated in the effective area(s) for setting into motion, each magnetic conduction element being separated as close as possible to the central axis of the whole of the ring by a set back distance of the magnetic circuit which is specific to it,
• characterised in that
• the ratio of the set back distance of any magnetic conduction element of any magnetohydrodynamic pump over half of the internal size of the fluid ring is greater than or equal to 0.5, preferably greater than or equal to 0.7, and
• the fluidic ring comprises at least two distinct effective areas, for setting the conductive liquid into motion, each centered around one of a respective radial middle half-plane and the two middle half-planes of which of two of them are angularly spaced by at least 120°.