Flow features induced by a rod-shaped microswimmer and its swimming efficiency:A two-dimensional numerical study  

作　　者：Siwen Li Yuxiang Ying Tongxiao Jiang Deming Nie 李斯文;应宇翔;姜童晓;聂德明(College of Metrology Measurement and Instrument,China Jiliang University,Hangzhou 310018,China;Institute of Fluid Engineering,Zhejiang University,Hangzhou 310018,China)

机构地区：[1]College of Metrology Measurement and Instrument,China Jiliang University,Hangzhou 310018,China [2]Institute of Fluid Engineering,Zhejiang University,Hangzhou 310018,China

出　　处：《Chinese Physics B》2024年第12期306-317,共12页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant Nos.12372251 and 12132015);the Fundamental Research Funds for the Provincial Universities of Zhejiang(Grant No.2023YW69)。

摘　　要：The swimming performance of rod-shaped microswimmers in a channel was numerically investigated using the two-dimensional lattice Boltzmann method(LBM).We considered variable-length squirmer rods,assembled from circular squirmer models with self-propulsion mechanisms,and analyzed the effects of the Reynolds number(Re),aspect ratio(ε),squirmer-type factor(β)and blockage ratio(κ)on swimming efficiency(η)and power expenditure(P).The results show no significant difference in power expenditure between pushers(microswimmers propelled from the tail)and pullers(microswimmers propelled from the head)at the low Reynolds numbers adopted in this study.However,the swimming efficiency of pushers surpasses that of pullers.Moreover,as the degree of channel blockage increases(i.e.,κincreases),the squirmer rod consumes more energy while swimming,and its swimming efficiency also increases,which is clearly reflected whenε≤3.Notably,squirmer rods with a larger aspect ratioεand aβvalue approaching 0 can achieve high swimming efficiency with lower power expenditure.The advantages of self-propelled microswimmers are manifested whenε>4 andβ=±1,where the squirmer rod consumes less energy than a passive rod driven by an external field.These findings underscore the potential for designing more efficient microswimmers by carefully considering the interactions between the microswimmer geometry,propulsion mechanism and fluid dynamic environment.

关 键 词：direct numerical simulations low-Reynolds-number motions multiphase flows swimming microorganisms 

分 类 号：TP242[自动化与计算机技术—检测技术与自动化装置]