Forma, Vol. 10 (No. 2), pp. 97-107, 1995
Original Paper

Deformation of a Liquid Drop Due to Rotation.
I. Measurement of the Internal Velocity Field and the Transition of a Drop Shape

Tadashi Onoguchi, Masayoshi Murakami and Osamu Sano

Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183, Japan

(Received March 14, 1995; Accepted April 8, 1995)

Keywords: Equilibrium Shape, Rotating Drop, Surface Tension, LDV Measurement, Coriolis Force

Abstract. A laser Doppler measurement was made on the velocity field of an almost neutrally buoyant rotating drop, which was suspended in a viscous fluid. An external torque was applied by rotating a rigid rod touching the drop, the angular velocity and angular acceleration of which were specified by a computer controlled motor. The drop shape and the velocity field inside the drop showed deviations from those of the rigid-body rotation as the rotation rate was increased. The critical angular velocity at the transition of the drop shape from spheroidal to two-lobed or pear-shaped one was measured.