Drag Coefficient of a Gas Bubble in an
Axisymmetric Shear Flow

S. Takagi and A. Prosperetti

Department of Mechanical Engineering
The Johns Hopkins University
Baltimore MD 21218

Y. Matsumoto

Department of Mechanical Engineering
The University of Tokyo
Tokyo 113, Japan



ABSTRACT: The drag coefficient of a gas bubble in steady motion in an unbounded axisymmetric shear flow is obtained numerically for different values of the Reynolds and Weber numbers and intensities of shear. The bubble is allowed to deform in response to the flow and zero-tangential-stress boundary conditions are imposed on its surface. The numerical method used is a modification of that of Ryskin and Leal [J. Fluid Mech. 148, 1, (1983)]. The results show that even small amounts of shear have a strong effect on drag. The drag coefficient decreases for a free-stream velocity decaying away from the axis, and increases in the opposite case.



Phys. Fluids 6, 3186-3188, 1994


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