Author(s): K Khalfaoui; J Bareis; S Riedelbauch

Linked Author(s):

Keywords: Fluid-induced vibrations; Imposed modal motion approach; Added mass; Added damping; Added stiffness

Abstract: A detailed mathematical modelling of the fluid-added quantities for flow-induced vibrations, i.e. the added mass, added damping, added stiffness and others, from a structural point of view is presented in the first part of this work, along with a graphical interpretation of the resulting forces. In the second part, the imposed modal motion approach (IMMA) is applied in conjunction with the theoretical foundation from the first part to derive equations that enable computing the fluid-added mass, damping, and stiffness. First, an approach based on the fluid force and the previously discussed graphical interpretation is introduced. It includes the case of coinciding modal and excitation frequencies which paves the way for applying the IMMA in operating regimes beyond best efficiency operation, where it has been commonly applied so far. Finally, the method is applied to a circular disc vibrating in spatially harmonic modes characterized by nodal diameters.

DOI: https://doi.org/10.1088/1755-1315/1483/1/012019

Year: 2023