Simulations of the whirling instability by the immersed boundary method

When an elastic lament spins in a viscous incompressible fluid it may undergo a whirling instability, as studied asymptotically by Wolgemuth, Powers, and Goldstein [Phys. Rev. Lett., 84 ( 2000), pp. 16 - 23]. We use the immersed boundary (IB) method to study the interaction between the elastic. lament and the surrounding viscous fluid as governed by the incompressible Navier - Stokes equations. This allows the study of the whirling motion when the shape of the. lament is very different from the unperturbed straight state.