Novel algorithm of tracking band-pass digital filter with amplitude 1/f2 attenuation for vortex signal extraction

A digital band-pass filter group for vortex signal extraction is proposed in this paper. The digital filter could attenuate vortex amplitude with 40 dB/dec, and the algorism could track the real vortex signal frequency. Offline simulation is carried out compared with autocorrelation algorithm, which shows that the novel algorithm has the ability to filter noise out better. Then the performance of online measurement is accessed. And the test results show that this novel algorithm improves the measurement accuracy and broadens the range limit especially in low flow velocity as Reynolds number ranges from 5×103 to 3.5×105.