A. B. Basset. On the motion of a sphere in a viscous liquid.pdf
A SPHERE IN A VISCOUS LIQUID
2&) (sin X
2<w e -A2^ (sin
whence th e velocity of the liquid, which is equal to v sin 0, can be found.
W hen the angular velocity is variable, the value of th e retarding couple, and the
equation of motion of the sphere, can be obtained by a process analogous to th a t
employed in § 11.
[March 10th, 1888.— Since this paper was read, a paper has been published in the
‘ Q uarterly Journal of M athematics,’* by Mr. W h i t e h e a d , in which he attem pts to
develope a method of obtaining approxim ate solutions of problems relating to the
motion of a viscous liquid, when the term s involving the squares and products of the
velocities are reta in e d ; and he applies his m ethod (see p. 90) to obtain expressions
fur the components in the plane passing through the axis of rotation, of the velocity
of a viscous liquid, which surrounds a sphere which is rotating about a fixed diameter,
when the motion has become steady. I t will be observed, however, th a t the expressions
for these components contain the coefficient of viscosity as a factor in the denominator,
and therefore become infinite when th e liquid is frictionless. I t would therefore
appear th a t th e method of approxim ation adopted is inapplicable to the problem
* Vol. 23, p. 78.