Slow viscous rotation of two spheres (Q1202617)

An attempt is made to improve some results obtained by \textit{P. V. Arunachalam} and \textit{S. N. Majhi} [Q.J. Mech. Appl. Math. 40, 47-55 (1987; Zbl 0609.76115)]. The slow and steady rotation of two identical spheres, rotating about their line of centres with the same angular velocity in an incompressible viscous fluid, is studied. The motion of the fluid is described by Navier-Stokes equations. The second order effects of Reynolds number are also taken into consideration. The values of the torque for different angular velocities are given. The authors established that, when the angular velocity increases, a reduction in torque on either sphere is obtained. The drag on either body is also found to be considerably reduced.