Dynamic measurements of the flow and structure oscillations to validate FSI calculations

Abstract This paper presents results of dynamic measurements of the flow and structure oscillations. We proposed a model consisting of two in-tandem flexible cylinders in the water cross-flow. During the studies, vibration acceleration amplitudes at the shedding frequency and at the cylinders natural frequency were obtained as a function of the flow velocity. The velocity pulsation and pressure pulsation spectra were determined in the flow. A relatively simple structure enabled the use of non-contact measurement systems for cross validation and uncertainty quantifications. The mutual influence of flow and structural dynamics induced by the lock-in effect between the vortex shedding frequency (or its harmonics) and the natural frequency was analyzed. These activities were conducted to generate representative data in order to validate the requirements for hydrodynamic force calculation accuracy and the methods of one-way and two-way coupled FSI calculations.