Excitation Models for Buffeting of Cylinder Bundles in Parallel Flow

In this paper, the effect of several models representing the state of the art in wall-pressure fluctuations statistics were applied to the geometry of square rod bundles with P/D = 1.33, and used together with the random vibration theory to yield the spectral characteristics of rod vibration. Comparison of model predictions with experimental data representing rod acceleration allowed the selection of Efimtsov model as better suited for the rod bundles flow geometry and low frequency range. Further assimilating the mixing-vanes induced swirling flow as a disturbance to the parallel flow, two corrections were proposed based on comparison of measured vibration characteristics of vaned and vaneless bundles.