Distribution and deformation of long flexible fibers in a turbulent channel flow

We investigate the dynamics of flexible fibers possessing varying lengths, flexibilities, and densities when suspended in turbulent channel flow with shear Reynolds numbers of 300 and 600, by means of performing direct numerical simulations in the Euler-Lagrange framework. Our simulations reveal a competition between two dominant mechanisms governing the fiber distribution - enhanced migration away from the wall due to varying fiber lengths, and a wallward migration driven by fiber inertia. We further examine the influence of the confinement imposed by the channel size on their distribution. Furthermore, we demonstrate the pronounced impact of the fibers' distribution on their collective deformation dynamics.