Nonlinear liquid sloshing in an upright circular container: Modal responses and higher-order harmonics

Nonlinear sloshing in an upright circular container near the lowest natural frequency is analyzed by using a fully nonlinear overset-mesh-based harmonic polynomial cell method, two weakly Narimanov–Moiseev-type multimodal models and linear method. Modal responses are extracted from results based on simple but accurate least-square procedure time series of free-surface wave elevations, which provides new ways to delve into underlying modal energy transfer between modes, as well verify validity ordering assumptions models. Wavelet analyses also performed for elevations generalized coordinates modes better understand time-frequency information higher harmonics process. Planar state, swirling periodically modulated state analyzed. It found that more dispersed among different means consequential. In general, energies lower symmetric antisymmetric modes. The show O(?1/3) O(?2/3) dominated only first second harmonics, respectively, while O(?) response contains non-negligible third contribution. At last, influence initial disturbance examined, demonstrating disturbances may lead rotation direction waves sloshing-wave transient stage, main characteristics robust independent conditions.