Fig. 8: Squirmer flow fields.
Visual chaotic collective dynamics of squirmers. a Snapshot illustrating the presence of clusters. b Velocity field v(r, t) and c vorticity field ω(r, t) = ∂vz/∂x − ∂vx/∂z of the system with Nsq = 833 squirmers, β = − 5, λ = 4, and the packing fraction ϕ = 0.6. The black lines with arrows indicate the streamlines of the fields (See Supplementary Movie 3, Supplementary Movie 5, and Supplementary Movie 6). The maximum values of the flow fields are \({v}_{\max }=6\times 1{0}^{-3}\sqrt{{k}_{B}T/m}\) and \({\omega }_{\max }=1.2\times 1{0}^{-3}\sqrt{{k}_{B}T/(m{a}^{2})}\), corresponding to the effective Péclet number Pe = 96 and \({\omega }_{\max }/(2\pi {D}_{R}^{0})=38\), and rb = 2bx = 4a, the diameter of the minor axis. For the velocity field, squirmer velocities (Eq. (4)) are averaged over 60 subsequent configurations separated by the time interval \(1{0}^{2}\sqrt{m{a}^{2}/({k}_{B}T)}\) and sorted into quadratic bins of length rb. The vorticity field is calculated by the five-point stencil method.
