Figure 3
From: Flow coupling between active and passive fluids across water–oil interfaces
Intradroplet circulatory flow depended on the thickness of the surrounding oil layer, Δ. (a–d) The circulation order parameter (COP) as a function of Δ for four droplet shapes. Across these droplets, the intradroplet flows varied rapidly when the oil layer was thinner than ~ 4 mm (red dashed line), whereas oil layers thicker than this limit did not affect intradroplet flows. Each error bar represents the standard deviation of the time-averaged COP. (e–h) Flow profiles of azimuthal velocity, \(v_{\theta }\), taken at droplet midplane. Each curve represents the averaged flow velocity of the data point shaded in the same color in the same row of a–d. These curves indicate that varying the thickness of the oil layer altered the net flow rates of the intradroplet flows.
