Lei, Shuaihao, Cheng, Li, Yang, Weixing, Xu, Wentao, Yu, Lei, Luo, Can, Jiao, Weixuan, and Shen, Jiantao
The feature extraction of pressure fluctuation signal (PFS) and flow state recognition of outlet passage have crucial engineering significance to guarantee the safe and reliable operation in mixed-flow pump as turbine (PAT). To accurately extract the dynamic multiscale features of PFS, a method based on variational mode decomposition (VMD) and refined composite variable-step multiscale multimapping dispersion entropy (RCVMMDE) is proposed. By applying VMD to PFS, intrinsic mode functions (IMFs) are obtained, and the RCVMMDE values for each IMF is then calculated. Model parameters based on the RCVMMDE indicator are then established and used as feature vectors for flow state recognition. Using the PFS at the outlet passage inlet as an example, this method extracts dynamic multiscale feature information of the outlet passage, which is validated through experimental and numerical simulations. The results show that this method achieves high accuracy, providing well-defined feature vectors and effectively capturing the dynamic multiscale features of the PAT and turbine systems. • The energy performance curve of mixed-flow PAT under different blade angles is revealed. • The dynamic pressure fluctuation characteristics in the PAT system are identified by VMD. • A novel nonlinear dynamic index,RCVMMDE, is used to extract the dynamic multiscale feature information of the PAT system. • Based on VMD and RCVMMDE, an eigenvector model parameter for flow state identification is established. [ABSTRACT FROM AUTHOR]