A fluid and heat flow problem arising in the soup-canning industry

In this paper we consider the problem of heat flow at large Peclet number t hrough viscous fluid (containing an air-bubble) in a rotating circular cyli nder. Gravity is assumed to act in a plane perpendicular to the axis of the cylinder, but end effects (due to the finite length of the cylinder) are i gnored. A one-dimensional diffusion equation for the transfer of heat betwe en streamlines, valid for any steady flow with closed streamlines, is deriv ed. The implications of our results for the UHT sterilization of canned liq uid foods are discussed.