Fig. 9
From: Oscillatory interactions of two spheres in an unbounded couple stress fluid
Drag force versus time t for different values of separation distance parameter with \(a_2/a_1=0.1,U_2/U_1=1.0,\bar{\eta }=0.1,\bar{\eta }'=0.01, \delta \rightarrow \infty\) for low frequency at \(\alpha =0.5\) (a) in-phase, (b) out-of-phase.
