Chirality-dependent forces in simple shear flow for helix aligned with streamlines

Abstract

We consider the chiral properties for a helix in uniform shear flow. We decompose the helical structure into arrays of [Formula: see text] closely packed beads with radius [Formula: see text]. In low Reynolds number regime, the chirality-specific lift forces in the vorticity direction experienced by helices are given by a set of helix geometry parameters: helix radius [Formula: see text], pitch length [Formula: see text], number of turns [Formula: see text] and helix phase angle [Formula: see text]. The analytical formula of the force is firstly given. The chirality-specific forces are the physical reasons for the chiral separation of helices in shear flow. Our results provide new insights into the separations of all kinds of chiral objects.