One of the challenging aspects about interface-resolved numerical simulation of two-phase flows is the correct representation of the conditions at inlet boundaries, which can lead to inaccuracies if they are not realistic [1]. For a flow regime with large gas bubbles, a long precursor domain can be used in which these bubbles develop, but this incurs a substantial computational cost. Therefore a different approach is used here, namely the Synthetic Bubble Model (SBM), developed by De Moerloose et al. [2]. This model creates a transient, non-uniform inlet profile which produces gas bubbles from the inlet, instead of relying on the break-up of a steady, continuous gas jet. The result is a reduced mesh size upstream of the region of interest. The technique has been tested by De Moerloose et al. [2] for the forces acting on rigid tube bundles, yielding satisfactory results. The current research takes it one step further, and also investigates the resulting vibration. To this end, fluid-structure interaction simulations of a tube bundle experiment in a cross-flow air/water-mixture are performed with the SBM at the inlet. In the experimental setup, air is injected in a water channel, after which the mixture enters the test section. The flow is conditioned by a few rows of rigid rods, with one or multiple moving rods located downstream. They are considered rigid bodies and their motion is enabled by mounting them on a flexible blade. Given that flow-induced vibrations are dominated by liquid impact, the Volume-of-Fluid approach is opted for. The vibrations are analyzed and the SBM technique for accurate representation of the inlet is validated by comparing the forces with the experimental values. [1] Ono, A., Yamashita, S., Suzuki, T., & Yoshida, H. (2020). Numerical simulation of two-phase flow in 4x4 simulated bundle. Mechanical Engineering Journal, 7(3). [2] De Moerloose, L., Bral, A., Demeester, T., De Paepe, M., & Degroote, J. (2021). Effect of a new synthetic bubble model on forces in simulations of two-phase flows in tube bundles. European Journal of Mechanics - B/Fluids, 90, 49-62.