Transient sensitivity analysis and topology optimization of particle suspended in transient laminar fluid

Abstract

This study develops a new topology optimization scheme using coupled forward and coupled sensitivity analyses to manipulate and control time-varying particle trajectories in transient laminar flow, that is transient fluid–particle assemblies. It is an important scientific and engineering subject to manipulate or control the trajectories of particles by the drag force in steady-state or transient fluids. The drag force varies with the material properties of fluid, and the velocity differences between fluid and particles cause the particles to move. Despite some research regarding the shape and topological optimization frameworks for particles in steady-state flow, the optimization of transient particle motion in transient laminar flow is still a difficult subject. Thus, this study presents a new topology optimization scheme that considers the transient motion of particles in transient laminar flow. Owing to the time variation in the direction and magnitude of the fluid, the optimization of particle motion requires a new development of the transient sensitivity analysis. For efficient optimization, a two-scale time integration scheme for the fluid and particle was developed. The developed coupled analysis and optimization framework were applied to determine optimal layouts for transient fluids and particles. Several optimization problems were formulated and solved to validate the present scheme.