2018 年 3 巻 p. 72-77
In this study, a novel dynamic mode decomposition (DMD) technique combining proper orthogonal decomposition (POD) and linear stochastic estimation (LSE) was developed. The availability was also examined experimentally for flow-induced sound from a forward-facing step by simultaneous measurements of surface pressure and resulting far-field sound in a low-noise wind tunnel, and the data obtained were analyzed by the proposed method. By using this method, a dominant surface-pressure-fluctuation mode, contributing to the sound radiation, was identified. Further, it was found that low-order POD modes of the surface-pressure-fluctuation of the step related to the large scale coherent structures did not necessarily have a strong impact on the far-field sound.