Study on the vortex-induced Helmholtz resonance with a cylindrical roof opening via high-order dynamic mode decomposition

The vortex-induced Helmholtz resonance (VIHR) is one special phenomenon of the internal pressure response due to the coupling of normal Helmholtz resonance and vortex shedding around the opening. In order to investigate the behavior of the VIHR, the wind tunnel test is conducted on the cylindrical roof structure with a single opening. The high-order dynamic mode decomposition (HODMD) method is introduced to reveal the spatial and temporal pattern of the VIHR. The fluctuating part of the net wind pressure on the cylindrical roof is amplified by the VIHR. The roof deformation induced by the VIHR is significantly larger than that induced by the normal Helmholtz resonance. The magnitude of VIHR is sensitive to geometrical parameters of internal volume, opening thickness and opening porosity. The VIHR can be inhibited by partitioning the internal space, equipping deflectors or louvers around the opening. The non-dimensional wind speed ( U * ) of VIHR lies in the range of 1.4–2.8 in the terrain type A of GB 50009–2012. The speed is higher in the empty tunnel with a lower turbulence intensity profile. Based on the governing equation of internal pressure, the theoretical model of VIHR is developed to reproduce the internal pressure response using key parameters of inertia ( C I ) and loss ( C L ) coefficients.