Rotation of axisymmetric bodies in hydromagnetics

Summary

This paper deals with the distrubance due to steady rotation of axisymmetric bodies in a viscous incompressible fluid of infinite conductivity in which the uniform ambient flow field is collinear with the uniform magnetic field. The known results of Sowerby¹) for the problem “Couple on a rotating spheroid” in a slow stream in an incompressible viscous fluid are generalized to apply to all ellipsoids of revolution and a special case of the circular disc has also been investigated in detail. The conditions of flow are assumed to be such as to permit the use of Oseen’s approximation in the equations of motion. The coefficient of couple has been found to the first order approximation in terms ofR(1−S) orR(S−1) whereR is the Reynolds number andS=H ²₀ /4πρ′W ² the pressure number which plays an important part. The couple exerted on the body is computed for various values ofS andR.