Defence Ali Fasihi: "Dynamics of Spinning Pipes Conveying Fluid"
Promotors: 1st Promotor: Prof. Maryam Ghandchi Tehrani, 2nd promotor: Prof. Grzegorz Kudra
Abstract: Think of the wild, snaking motion of a garden hose when you drop it on the ground, or the kick you feel in your hand when you open the tap too far. These are instabilities caused by flow. Combining them with rotation makes the situation far more sophisticated — and this thesis handles them.
This thesis develops a general mathematical model that precisely predicts how such a system behaves across a wide range of speeds and flow rates — identifying when it stays stable, when it loses stability, and the kinds of motion it settles into afterwards. The model applies broadly, from kilometre-long marine risers and deep-sea mining pipes drawing oil and minerals up from the seabed, all the way down to micro-scale resonators.