A231 ウェーブレット変換による開水路凹部流れの組織運動の特性抽出

概要

論文の詳細を見る
Velocity fields measured by a particle image velocimetry (PIV) are analyzed by using a continuous wavelet transform (CWT). Considered here are organized motions in the mixing layer of turbulent open-channel flow over a concave bed. By applying the CWT to an instantaneous velocity distribution along the mixing layer, the locations and spatial scales of the organized motions have been extracted from the extremal values of wavelet coefficient. Then, the characteristics of the organized motions, such as the evolution of the spatial scale, advection velocity, and occurrence interval, are successfully obtained using the locations of the extremal values in each time step. The joint probability distribution of the spatial scale and the temporal scale shows that there is a linear relationship between them. These results suggest that the wavelet transform is a useful tool for extracting the organized motions embedded on the velocities obtained by PIV measurement.
日本流体力学会の論文
2000-07-25