The motion of two-filament artificial swimmers is modeled by assuming interfilament coupling via hydrodynamic viscous drag. The filaments are assumed to be in parallel and attached to a rigid spherical head. The boundary actuation is assumed to occur at the head-filament joint through an external oscillatory magnetic field and the filament motion is taken to be confined to the flexural plane. The hydrodynamic coupling modifies the viscous drag on one filament due to motion of the other. Assuming in-phase, small amplitude, low frequency actuation the swimmer performance metrics (propulsive thrust, propulsion speed and energy efficiency) are calculated using Lauga's formulation for the swimmer kinematics coupled with filament dynamics. The results are compared with the performance of a single-filament and an uncoupled two-filament swimmer. The hydrodynamic coupling is found to enhance the performance measures in a parametric window. Also, it is found that there occurs an optimum combination of head size and swimmer length that can maximize the microswimmer performance. The findings are in agreement with the experimental observations on multi-filament artificial microswimming.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1039/c8sm01120f | DOI Listing |
Biomimetics (Basel)
December 2024
Department of Aeronautics and Astronautics, National Cheng Kung University, Tainan 701, Taiwan.
In this study, a fish scale structure with low viscous drag was proposed and applied to the suction surface of a compressor cascade to reduce total pressure loss and suppress corner separation, a key source of compressor inefficiency. By using CFD simulations, the biomimetic structure was identified and integrated into the cascade design. To evaluate its effects, we analyzed secondary flow structures using 2D projected streamlines, axial velocity density (AVD), and vortex visualization techniques.
View Article and Find Full Text PDFBrain Multiphys
December 2024
Department of Radiology, Mayo Clinic, Rochester, MN, USA.
Background And Purpose: Idiopathic normal pressure hydrocephalus (iNPH) is a cerebrospinal fluid (CSF) dynamics disorder as evidenced by the delayed ascent of radiotracers over the cerebral convexity on radionuclide cisternography. However, the exact mechanism causing this disruption remains unclear. Elucidating the pathophysiology of iNPH is crucial, as it is a treatable cause of dementia.
View Article and Find Full Text PDFMicrosyst Nanoeng
December 2024
School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai, 200237, China.
Langmuir
December 2024
School of Mechanical Engineering, Dalian University of Technology, Dalian 116024, China.
The generation of surface acoustic waves (SAW) through electrically driven piezoelectric devices has attracted considerable attention in both fundamental research and practical applications, particularly for suppressing bacterial adhesion on surfaces. However, the precise mechanism by which SAW prevents bacterial attachment remains incompletely understood. This study explores the impact of SAW-induced boundary-driven streaming on the surface adhesion of and in a liquid environment, focusing on the prevention of bacterial adhesion through the formation of micrometer-scale shielding fluid layers.
View Article and Find Full Text PDFJ Anat
November 2024
Experimental Zoology Group, Wageningen University, Wageningen, The Netherlands.
Most teleost fish propel themselves with lateral body waves powered by their axial muscles. These muscles also power suction feeding through rapid expansion of the mouth cavity. They consist of muscle segments (myomeres), separated by connective tissue sheets (myosepts).
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!