Magnetohydrodynamic inertial actuator
AssigneesCentre National D'Etudes Spatiales, Institut National Polytechnique De Toulouse, Centre National de la Recherche Scientifique (CNRS)
InventorsChristophe Casteras, Yvan Lefevre, Dominique Harribey
Life of this patent
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Abstract
An inertial actuation magnetohydrodynamic wheel (2) comprising a torus-shaped fluid ring (3) filled with a conductive liquid, at least one effective area (24, 26, 28) for setting the liquid into motion, and at least one magnetohydrodynamic pump (4, 6, 8). The ratio of the set back distance of any magnetic conduction element (24, 26, 28) of the air gap of any electromagnetic pump (4, 6, 8) over the internal size of the fluid ring (3) is greater than or equal to 0.5 and the fluid ring (3) comprises at least two distinct effective areas (24, 26), for setting the conductive liquid into motion, angularly spaced apart by at least 120°.
Claims11
An inertial actuator for pointing a platform along a predetermined direction comprising:
- a fluid ring having a torus shape around a central axis, the fluid ring including a central ring hole having a diameter, the central ring hole crossed by a central axis, the fluid ring having an internal size equal to the diameter of the central ring hole, the fluid ring being filled with a conductive liquid, the fluid ring having at least one air gap portion which is defined as a portion crossed by a magnetic field, and at least one effective portion which is defined as a portion where the conductive liquid is set into motion;
- at least one magnetohydrodynamic pump for setting the conductive liquid into motion around the central axis of the fluid ring,
- each magnetohydrodynamic pump having only one air gap, the air gap being associated with one air gap portion of the fluid ring and with the at least one effective portion of the fluid ring that is located inside the air gap portion,
- each magnetohydrodynamic pump including only one means for generating a magnetic field through the air gap thereof, and including a magnetic conduction element which, conducts and channels the magnetic field through the at least one effective area portion and is separated from the central axis by a set back distance;
- and
- a synchronization circuit, connected to each pump of the at least one magnetohydrodynamic pump and configured for synchronising an amplitude of the magnetic field generated by each pump of the at least one magnetohydrodynamic pump so as to minimise an energy consumed by the at least one magnetohydrodynamic pump when the conductive liquid rotates at a predetermined rotational speed,
- wherein the ratio of the set back distance of the magnetic conduction element over the half of the internal size of the fluid ring is greater than or equal to 0.5 and wherein
- the fluid ring comprises a number P of effective portions, P being an integer greater than or equal to two, each effective portion being centered around a radial middle half-plane, one radial middle half-plane being angularly spaced apart from the next radial middle half-plane by a pitch, said pitch being equal to 360° divided by the number P of effective portions.
Dependencies are inferred from the claim text.