  The dynamics of elongated inertial particles in an extensional flow is
studied numerically by performing simulations of freely jointed bead-rod
chains. The coil-stretch transition and the tumbling instability are
characterized as a function of three parameters: The Peclet number, the Stokes
number and the chain length. Numerical results show that in the limit of
infinite chain length, particles are trapped in a coiled or stretched state.
The coil-stretch transition is also shown to depend non-linearly on the Stokes
and Peclet number. Results also reveal that tumbling occurs close to the
coil-stretch transition and that the persistence time is a non-linear function
of Stokes and Peclet numbers.
