Hydrodynamics of an inertial squirmer and squirmer dumbbell in a tube

• DOI: 10.1017/jfm.2022.210
• Publication Date: 2022-03-31T14:09:37Z
• Authors: Zhenyu Ouyang; Zhaowu Lin; Zhaosheng Yu; Jianzhong Lin; Nhan Phan-Thien
• Keywords: Dumbbell

We study the hydrodynamics of a spherical and dumbbell-shaped microswimmer in tube. Combined with squirmer model generating tangential surface waves for self-propulsion, direct-forcing fictitious domain method is employed to simulate swimming microswimmers. perform simulations by considering variations Reynolds numbers ( Re ), blockage ratios κ ) relative distances d s between squirmers dumbbell. The results show that dumbbell weakens inertia effects fluid more than an individual squirmer. constrained tube can speed up inertial pusher (propelled from rear) dumbbell; greater distance slower but faster puller front) also illustrate stability (stable) (unstable) at = 0. At finite , we find constraint competitively affect dumbbells. dumbbells become unstable increasing whereas unstable–stable–unstable evolution found With stable while unstable. In addition, yields higher hydrodynamic efficiency η