Fig. 11
From: Oscillatory interactions of two spheres in an unbounded couple stress fluid
Drag force versus separation distance for different values of velocity ratio with \(U_2/U_1=0.5,\bar{\eta }=0.001,\bar{\eta }'=0.0, \delta \rightarrow \infty , t=4.0\) at \(\alpha =0.5\),\(a_2/a_1=1.0\) for (a) in-phase, and \(a_2/a_1=2.0\) for (b) out-of-phase.
