Gas bubble dynamics in airlift photo-bioreactors for microalgae cultivation by level set methods

Neviani, Matteo; Bagnerini, Patrizia; Paladino, Ombretta

doi:10.1016/j.fuel.2021.120402

Cited by 13 publications

(6 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As shown in Figure S5, when U g increases, the density of the ″vertical plumb line″ in the high-frequency range (f > 7.5 Hz) decreases, indicating that the high-frequency fluctuations are weakened, which is presumed to be because the increasing U g enhances the frequency of the collision of bubbles with each other, which increases the degree of bubble merging. 46 Luo et al 47 concluded that the movement of tiny bubbles causes high-frequency pressure fluctuations by analyzing the pressure fluctuation signals, which supports the results of the present study.…”

Section: Industrial and Engineeringsupporting

confidence: 91%

Time Domain, Frequency Domain, and Time–Frequency Domain Analysis of Axial Liquid Velocity Signals under the Influence of Internal Components

Wang

Zeng

et al. 2023

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

In the annular gap bubble bed of the scrubbingcooling chamber, the instantaneous signals of local gas holdup and axial liquid velocity were measured using a conductivity probe and a pitot tube under different bubble-breaking plate installation conditions. The detailed information contained in the axial liquid velocity signals was obtained by time-domain analysis ((temporal distribution, skewness, kurtosis), frequency−domain analysis (power spectral density), and time−frequency−domain analysis (short-time Fourier transform, wavelet analysis). The results showed that the local axial liquid velocity has certain temporal nonsmoothness and spatial nonuniformity; liquid phase fluctuations, vortex structure, and bubble aggregation lead to the dominant role of liquid velocity fluctuations in the low-frequency range. The bubble-breaking effect of the bubble-breaking plate contributes to the enhancement of the smoothness and uniformity of the axial liquid velocity distribution, as well as to the attenuation of the power spectrum density, the reduction of low-frequency fluctuations, the enhancement of high-frequency fluctuations, the local dynamic complexity, the weakening of coherent vortex structure, and the intensity of the turbulence. Staggering the two plates is the best-performing bubble-breaking plate installation.

show abstract

Section: Industrial and Engineeringsupporting

confidence: 91%

Time Domain, Frequency Domain, and Time–Frequency Domain Analysis of Axial Liquid Velocity Signals under the Influence of Internal Components

Wang

Zeng

et al. 2023

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

show abstract

“…The causes of bubble collision in turbulent flow mainly include the turbulent fluctuation of the continuous phase, uneven velocity gradient, different rising velocities caused by buoyancy, the capture of bubbles by vortex, and the entrainment of wake . The U g increase can promote bubbles’ coalescence by increasing the collision frequency between bubbles, thereby increasing the bubble size . However, the interference of turbulence fluctuation, collision, and shear stress can also enhance the interfacial instability of bubbles and provide energy for bubble rupture.…”

Section: Resultsmentioning

confidence: 99%

“…58 The U g increase can promote bubbles' coalescence by increasing the collision frequency between bubbles, thereby increasing the bubble size. 59 However, the interference of turbulence fluctuation, collision, and shear stress can also enhance the interfacial instability of bubbles and provide energy for bubble rupture. Coalescence makes larger bubbles more likely to rupture.…”

Section: Effect Of the Predicted Value Of K On P P (R B )mentioning

confidence: 99%

Prediction of Bubble Size Distribution above the Bubble-Breaking Plate

Wang

Zeng

et al. 2023

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

The chord length distribution (CLD) of bubbles in the region above the bubble-breaking plate in the scrubbing−cooling chamber was studied experimentally using a conductivity probe. The predictive correlations of the shape parameters were established by fitting the CLD with a distribution function. The bubble shape was discussed, and the CLD was analytically converted to the size distribution of the direct contact of the probe. The results showed that the CLD has specific right-skewed characteristics, and the Rayleigh distribution has the best-fitting effect on the CLD. The correlation equation of the shape parameter k of the Rayleigh distribution concerning the Fr number, local gas holdup ε g , and dimensionless radius r/R was established. The predicted bubble size distributions (BSDs) based on ellipsoids are in good morphological agreement with the experimental size distributions. The relative error between the calculated and experimental values of the gas−liquid interface area was within ±20%, which verified the accuracy of the prediction of the BSD.

show abstract

“…The relevance of this work concerns the potential application to the control of shape dynamics or moving fronts/interfaces, usually modelled by means of normal flow equations in two or higher dimensions, for which the present results hold. Thus, future efforts will be devoted to the control of more complicated systems such as airlift bioreactors (see, e.g., [21], [22]) or in general multi-phase flows described by Navier-Stokes equations combined with NF equations to account for moving interfaces (e.g., bubble dynamics for bioreactors), while providing robustness guarantees in terms of ISS.…”

Section: Discussionmentioning

confidence: 99%

Control of Normal Flow PDEs with ISS Properties

Alessandri

Bagnerini

Prieur

et al. 2021

2021 60th IEEE Conference on Decision and Control (CDC)

Self Cite

View full text Add to dashboard Cite

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

show abstract

Gas bubble dynamics in airlift photo-bioreactors for microalgae cultivation by level set methods

Cited by 13 publications

References 41 publications

Time Domain, Frequency Domain, and Time–Frequency Domain Analysis of Axial Liquid Velocity Signals under the Influence of Internal Components

Time Domain, Frequency Domain, and Time–Frequency Domain Analysis of Axial Liquid Velocity Signals under the Influence of Internal Components

Prediction of Bubble Size Distribution above the Bubble-Breaking Plate

Control of Normal Flow PDEs with ISS Properties

Contact Info

Product

Resources

About