Multiphase flow can induce high amplitude vibrations in piping systems. Several experimental campaigns focused on the force spectrum on a single bend. To evaluate the evolution of the forces from bend to bend, experiments have been done on an air-water, one inch pipe system consisting of six bends at near-atmospheric conditions. In a first phase, all individual bends were clamped to measure the phase relation and correlation of the flow-induced forces on the subsequent bends. In a second phase, all clamps were removed to measure the free vibrations. In this paper which focusses on the phase 2 results, the vibration measurements were compared to the calculated vibrations. For the excitation forces and phase relations, the measured force spectra from phase 1 are used. Damping values are based on experimental results from phase 2. The results show a good match between modeled and measured vibrations levels. Including the measured correlation between forces at multiple bends, improves the modeled results for slug flow cases. It is possible to directly use extract damping values from the measured signals, however, robustness of the damping estimation needs to be improved. Using average damping values currently leads to the best match.

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