Fluid-structure interaction in a T-piece pipe

Experimental measurements in a simple laboratory apparatus are presented and shown to be suitable as benchmark data for the validation of computer software. The apparatus consists of suspended horizontal pipes which are struck externally by a long horizontal rod. Attention is focused on interactions between stress waves in the pipes and pressure waves in the contained liquid. Cavitation, external restraints and pre-existing pressure gradients are all absent. It is demonstrated that coupling at boundaries and, to a lesser extent, coupling at wavefronts propagating along a pipe can have a major influence on stress and pressure histories. It is also shown that coupling changes the fundamental frequencies of vibration in comparison with those deduced by considering the liquid and solid components alone. (C) 1996 Academic Press Limited