Quantitative evaluation of flow-induced structural vibration and noise in turbomachinery by full-scale weakly coupled simulation

This article reports on a full-scale structural simulation of flow-induced mechanical vibrations and noise in a 5-stage centrifugal pump. An interior flow field is simulated by an LES-based CFD program, which can be found elsewhere. We developed a data-interface tool to enable mesh matching and data transfer between the fluid and structure meshes. The vibration of the pump's structure was simulated using a parallel explicit dynamic FEM code. This provided a time series of pressure fluctuations on the internal surface as force-boundary conditions. The calculated vibration of the outer surface of the structure agrees reasonably well with measured data. Using Fourier transformation, the vibration modes at blade passing frequencies (BPFs) were extracted and presented as a visual image. The simulation clarified the mechanisms of resonant noise generation and propagation, which can then be used for noise reduction. This study shows that it is feasible to use fluid–structure weakly coupled simulations to estimate the flow-induced noise generated in turbomachinery.