The force on a sphere moving through a conducting fluid in the presence of a magnetic field

Autor: J. R. Reitz, L. L. Foldy
Rok vydání: 1961
Předmět:
Zdroj: Journal of Fluid Mechanics. 11:133-142
ISSN: 1469-7645
0022-1120
DOI: 10.1017/s0022112061000901
Popis: The force on a sphere moving through an inviscid, conducting fluid in the presence of a uniform magnetic field B0 is calculated for the low-conductivity case where the hydrodynamic motion deviates only slightly from potential flow. The magnetic Reynolds number is assumed small. The force on the sphere is found to consist of both a drag and a deflective component which tends to orient its motion parallel to a magnetic field line; if the sphere's velocity is V, the force may be written $\bf {R} = -AB^2_0\bf {V} + \bf C(V.B_0)B_0$ where the coefficients A and C depend on the conductivities of both sphere and fluid. The coefficients are evaluated by calculating the Joule dissipation for particular orientations of V relative to B0. In one case the force is also calculated directly from the perturbed pressure distribution in the fluid. In an analogous way, a spinning sphere in a conducting fluid experiences both resistive and gyroscopic torques.
Databáze: OpenAIRE