Transient dispersion process of active particles

Active particles often swim in confined environments. The transport mechanisms, especially the global one as reflected by Taylor dispersion model, are of great practical interest to various applications. For active process flows, previous analytical studies focused on long-time asymptotic values characteristics. Only several numerical preliminarily investigated temporal evolution. Extending recent Jiang & Chen (J. Fluid Mech., vol. 877, 2019, pp. 1--34; J. 899, 2020, A18), this work makes first attempt investigate transient process. evolution local distribution confined-section--orientation space, drift, dispersivity and skewness, is explored based moments distributions. We introduce biorthogonal expansion method for solutions because classic integral transform passive problems not applicable due self-propulsion effect. Two types boundary condition, reflective condition Robin wall accumulation, imposed respectively. A detailed study spherical ellipsoidal swimmers dispersing a plane Poiseuille flow demonstrates influences swimming, shear flow, accumulation particle shape after point-source release. swimming-induced diffusion reach its equilibrium state faster than that particles. Though significantly affects time scale regime obviously changed. shear-induced alignment can enlarge but has less influence drift skewness.