(562g) Experimental Study on Characteristics of Pressure Fluctuating Signals in the Novel Circulating Jet Mixer

Experimental
study on characteristics of pressure fluctuating signals in the novel
circulating jet mixer

Huibo
Meng, Yanfang Yu, Jianhua Wu

Key
Laboratory of Liaoning Province for Efficient Chemical Mixing Technology, School
of Energy and Power Engineering, Shenyang University of Chemical Technology

Abstract:

A novel Circulating
Jet Mixer (CJM) has been put forward as a novel type unites operation for
mixing. By compassion with conventional stirrers, the novel CJM had effectively
improved the flow structures in the tank reactor and exhibited outstanding
performance in chemical process intensification field. The flow characteristics
in the novel CJR had not been reported by now.

Pressure fluctuation
time series signals at different conditions were measured by the high precision
data-acquisition system. The spatial distributions of pressure fluctuation
amplitudes varied with different position and increased with the increase of
Re. The power spectrums distributions in frequency domain were analyzed and the
values of inherent frequencies were lower than 5 Hz. The power-law attenuation
relationship between power spectral density amplitude and frequency was
discovered. The probability distribution functions of the pressure fluctuations
were obtained and compared with the corresponding normal distributions by ¦Ö2 hypothesis test. The
deviation from the normal distribution was quantitatively analyzed based on
skewness and flatness. The Hilbert-Huang Transform was used to process
time-frequency and energy characteristic of the instantaneous pressure time
series in the novel CJM.

Intrinsic Mode Entropy
was also firstly introduced to reveal the sequence complexity of the pressure
fluctuation time series in the novel CJR. The regularities of sample entropy
and the intrinsic mode entropy were revealed at different parameters. The
scaling law of extended self-similarity for the nth-order structure function of
the pressure increment had been analyzed in the temporal-spatial scales.

The nonlinear dynamics
characteristics of flow field in CJR were investigated by using a new chaotic
attractor morphological analysis method based on Takes Theory. Both attractor
moment and the perimeter measure analysis of attractor area were employed to
evaluate the morphological evolution of the attractor in its unfolding process.
The recurrence plot and recurrence quantification analysis was introduced to
reveal the recursion phenomenon in the novel CJM.