Some unresolved issues in fluid-structure interactions

Three of the many unresolved or partly resolved issues in fluid-structure interactions are discussed in this paper: (i) the existence of post-divergence flutter of shells with supported ends (an inherently conservative system in the absence of dissipation) subjected to axial flow; (ii) the possible instability of shells with mismatched end-supports containing flow, at infinitesimal flow velocities; (iii) the stability of aspirating cantilevered pipes. The contents of this paper served as the foundation for a plenary lecture delivered at the 8th International Conference on Flow Induced Vibrations (FIV-2004) at Ecole Polytechnique, Paris, in July 2004.