摘要
本研究采用光滑粒子动力学(Smooth Particle Hydrodynamics,SPH)方法模拟单个squirmer在二维顶盖、双盖驱动方腔流中的流体动力学行为.通过系统地研究squirmer初始位置、squirmer尺寸、游动参数β、以及颗粒雷诺数(Res)对squirmer游动的影响,揭示了squirmer在稳态方腔流中的受限行为.结果显示,在顶盖驱动方腔流中,squirmer的初始位置与初始方向对其游动行为和稳态受限区域影响有限.小尺寸的中性squirmer易被流场限制于腔体左上角低压区域,而大尺寸中性squirmer则在腔体中部进行周期性绕圈运动.不同β的squirmer表现出不同的受限行为,其中,中性squirmer以及|β|较小的pusher通常被限制在腔体左上角低压区;而puller和|β|较大的pusher则受限于腔体右下角区域.对于三种类型的squirmer受限行为有着显著和复杂的影响.对于双盖驱动方腔流,所有类型的squirmer在低Res下均表现出相似的受限行为,均在腔体中心附近进行周期性环形运动,但随着Res的增加,其运动区域向外扩展,并最终被限制在腔体的右下角区域.本研究为理解微生物在受限空间中的流体动力学行为提供了新的见解.
This study investigates the dynamics of a single squirmer within a two-dimensional lid-driven and double-lid-driven square cavity flow using Smooth Particle Hydrodynamics(SPH)method.Through a comprehensive investigation of the effects of initial position,squirmer size,swimming parameterβand particle Reynolds number(Res)on the squirmer motion,the study reveals the confined behavior of squirmers within steady-state cavity flows.In lid-driven square cavity flows,the initial position of the squirmer has a minimal effect on its swimming behavior and the region of steady-state confinement.Small-sized neutral squirmers are readily confined by the flow to the low-pressure region in the upper left corner of the cavity,while large-sized neutral squirmers engage in periodic circular motion in the cavity's central region.squirmers with differentβexhibit different confined behaviors.Neutral squirmers and pusher with small|β|are generally confined to the low-pressure region in the upper left corner,while puller and pusher with larger|β|are confined to the lower right corner.The R e s significantly and intricately affects the confined behavior of the three types of squirmers.In double-lid driven square cavity flows,all types of squirmers demonstrate analogous confined behaviors at low R e s,primarily performing periodic circular motions near the cavity's center.However,as R e s increases,their motion area expands outward and eventually becomes confined to the lower right corner of the cavity.This study offers novel perspectives on the fluid dynamics of microorganisms within confined environment.
作者
朱昕辰
蔡鑫伟
严微微
边鑫
ZHU Xinchen;CAI Xinwei;YAN Weiwei;BIAN Xin(College of Metrology Measurement and Instrument,China Jiliang University,Hangzhou 310020,Zhejiang,China;State Key Laboratory of Fluid Power and Mechatronic Systems,Department of Engineering Mechanics,Zhejiang University,Hangzhou 310027,Zhejiang,China)
出处
《力学季刊》
北大核心
2025年第2期429-445,共17页
Chinese Quarterly of Mechanics
基金
国家自然科学基金(12172330)。
关键词
Squirmer
受限环境
光滑粒子动力学
方腔流
自驱动
squirmer
confined environment
smooth particle hydrodynamics
square cavity flow
self driving
