Imperial College London
Alternate

Dr. Yongyun Hwang

Faculty of Engineering, Department of Aeronautics

Reader in Fluid Mechanics
 
 
 
//

Contact

 

+44 (0)20 7594 5078y.hwang

 
 
//

Location

 

337City and Guilds BuildingSouth Kensington Campus

//

Summary

 

Publications

Citation

BibTex format

@article{Fung:2022:10.1017/jfm.2022.10,
author = {Fung, L and Bearon, RN and Hwang, Y},
doi = {10.1017/jfm.2022.10},
journal = {Journal of Fluid Mechanics},
title = {A local approximation model for macro-scale transport of biased active  Brownian particles in a flowing suspension},
url = {http://dx.doi.org/10.1017/jfm.2022.10},
volume = {935},
year = {2022}
}
Download

RIS format (EndNote, RefMan)

TY  - JOUR
AB  - A dilute suspension of motile microorganisms subjected to a strong ambient flow, such as algae in the ocean, can be modelled as a population of non-interacting, orientable active Brownian particles (ABPs). Using the Smoluchowski equation (i.e. Fokker–Planck equation in space and orientation), one can describe the non-trivial transport phenomena of ABPs such as taxis and shear-induced migration. This work transforms the Smoluchowski equation into a transport equation, in which the drifts and dispersions can be further approximated as a function of the local flow field. The new model can be applied to any global flow field due to its local nature, unlike previous methods such as those utilising the generalised Taylor dispersion theory. The transformation shows that the overall drift includes both the biased motility of individual particles in the presence of taxis and the shear-induced migration in the absence of taxis. In addition, it uncovers other new drifts and dispersions caused by the interactions between the orientational dynamics and the passive advection–diffusion of ABPs. Finally, the performance of this model is assessed using examples of gyrotactic suspensions, where the proposed model is demonstrated to be most accurate when the biased motility of particles (i.e. taxis) is weak.
AU  - Fung,L
AU  - Bearon,RN
AU  - Hwang,Y
DO  - 10.1017/jfm.2022.10
PY  - 2022///
SN  - 0022-1120
TI  - A local approximation model for macro-scale transport of biased active  Brownian particles in a flowing suspension
T2  - Journal of Fluid Mechanics
UR  - http://dx.doi.org/10.1017/jfm.2022.10
UR  - http://arxiv.org/abs/2103.03619v2
UR  - http://hdl.handle.net/10044/1/93785
VL  - 935
ER  -
Download