Fluctuating Characteristics of the Stilling Basin with a Negative Step Based on Hilbert-Huang Transform

The violent fluctuation of hydrodynamic pressure in stilling basins is an important factor threatening the safety bottom plates basins, and plays role safe operation basins. In order to deeply understand fluctuating characteristics signal a basin plate processed by Hilbert-Huang transform method through hydraulic model test. this paper, three decomposition methods are used decompose pulsating signal. A Hilbert select component with best effect. time-frequency-amplitude diagram obtained transform, its time-frequency discussed depth. analysis results as follows: (a) from CEEMD orthogonal complete. HHT suitable for processing signals. (b) With increase IMF order, frequency band becomes narrow, spectrum amplitude decreases energy decreases. into components different scales shows that turbulence composed multiple vortices, reflecting vortex structure turbulence. (c) jet impingement zone drop bucket near x/L = 0.075. dominant marginal very prominent, mostly concentrated within 5.0 Hz. (d) At height flow ratio, decreases, head larger, middle rear parts tends be stable, finally stabilized at about 1.0 This paper attempts use process signal, provide new discussion exploring structures.