Bubble shapes in a liquid-filled rotating container under low gravity

Abstract

The effect of surface tension on steady-state rotating fluids in a low-gravity environment is studied. AH values of the physical parameters used in the present calculations, except in the low-gravity environments, are based on the measurements carried out by Leslie in the low-gravity environment of a free-falling aircraft. The profile of the interface of two fluids is derived from Laplace's equation relating pressure drop across an interface to the radii of curvature that has been applied to a low-gravity rotating bubble that contacts the container boundary. The interface shape depends on the ratio of gravity to surface-tension forces, the ratio of centrifugal to surface tension forces, the contact radius of the interface to the boundary, and the contact angle. The shape of the bubble is symmetric about its equator in a zero-gravity environment. This symmetry disappears and gradually shifts to parabolic profiles as the gravity environment becomes nonzero. The location of the maximum radius of the bubble moves upward from the center of the depth toward the top boundary of the cylinder as gravity increases. The contact radius of interface to the boundary r0 at the top side of cylinder increases, and r0 at the bottom side of the cylinder decreases as the gravity environment increases from zero to 1 g.