Research output: Contribution to journal › Article › peer-review

**Fluid transport by individual microswimmers.** / Pushkin, Dmitri O.; Shum, Henry ; Yeomans, Julia M.

Research output: Contribution to journal › Article › peer-review

Pushkin, DO, Shum, H & Yeomans, JM 2013, 'Fluid transport by individual microswimmers', *Journal of Fluid Mechanics*, vol. 726, pp. 5-25. https://doi.org/10.1017/jfm.2013.208

Pushkin, D. O., Shum, H., & Yeomans, J. M. (2013). Fluid transport by individual microswimmers. *Journal of Fluid Mechanics*, *726*, 5-25. https://doi.org/10.1017/jfm.2013.208

Pushkin DO, Shum H, Yeomans JM. Fluid transport by individual microswimmers. Journal of Fluid Mechanics. 2013 Jul;726:5-25. https://doi.org/10.1017/jfm.2013.208

@article{a7cd01639d1b47d7b37ad61a257d1ffc,

title = "Fluid transport by individual microswimmers",

abstract = "We discuss the path of a tracer particle as a microswimmer moves past on an infinite, straight trajectory. If the tracer is sufficiently far from the path of the swimmer it moves in a closed loop. As the initial distance between the tracer and the path of the swimmer ρ decreases, the tracer is displaced a small distance backwards (relative to the direction of the swimmer velocity). For much smaller tracer–swimmer separations, however, the tracer displacement becomes positive and diverges as ρ→0. To quantify this behaviour we calculate the Darwin drift, the total volume swept out by a material sheet of tracers, initially perpendicular to the swimmer path, during the swimmer motion. We find that the drift can be written as the sum of a universal term which depends on the quadrupolar flow field of the swimmer, together with a non-universal contribution given by the sum of the volumes of the swimmer and its wake. The formula is compared to exact results for the squirmer model and to numerical calculations for a more realistic model swimmer.",

keywords = "Biological fluid dynamics, low-Reynolds-number flows, Mixing",

author = "Pushkin, {Dmitri O.} and Henry Shum and Yeomans, {Julia M.}",

year = "2013",

month = jul,

doi = "10.1017/jfm.2013.208",

language = "English",

volume = "726",

pages = "5--25",

journal = "Journal of Fluid Mechanics",

issn = "0022-1120",

publisher = "Cambridge University Press",

}

TY - JOUR

T1 - Fluid transport by individual microswimmers

AU - Pushkin, Dmitri O.

AU - Shum, Henry

AU - Yeomans, Julia M.

PY - 2013/7

Y1 - 2013/7

N2 - We discuss the path of a tracer particle as a microswimmer moves past on an infinite, straight trajectory. If the tracer is sufficiently far from the path of the swimmer it moves in a closed loop. As the initial distance between the tracer and the path of the swimmer ρ decreases, the tracer is displaced a small distance backwards (relative to the direction of the swimmer velocity). For much smaller tracer–swimmer separations, however, the tracer displacement becomes positive and diverges as ρ→0. To quantify this behaviour we calculate the Darwin drift, the total volume swept out by a material sheet of tracers, initially perpendicular to the swimmer path, during the swimmer motion. We find that the drift can be written as the sum of a universal term which depends on the quadrupolar flow field of the swimmer, together with a non-universal contribution given by the sum of the volumes of the swimmer and its wake. The formula is compared to exact results for the squirmer model and to numerical calculations for a more realistic model swimmer.

AB - We discuss the path of a tracer particle as a microswimmer moves past on an infinite, straight trajectory. If the tracer is sufficiently far from the path of the swimmer it moves in a closed loop. As the initial distance between the tracer and the path of the swimmer ρ decreases, the tracer is displaced a small distance backwards (relative to the direction of the swimmer velocity). For much smaller tracer–swimmer separations, however, the tracer displacement becomes positive and diverges as ρ→0. To quantify this behaviour we calculate the Darwin drift, the total volume swept out by a material sheet of tracers, initially perpendicular to the swimmer path, during the swimmer motion. We find that the drift can be written as the sum of a universal term which depends on the quadrupolar flow field of the swimmer, together with a non-universal contribution given by the sum of the volumes of the swimmer and its wake. The formula is compared to exact results for the squirmer model and to numerical calculations for a more realistic model swimmer.

KW - Biological fluid dynamics

KW - low-Reynolds-number flows

KW - Mixing

U2 - 10.1017/jfm.2013.208

DO - 10.1017/jfm.2013.208

M3 - Article

VL - 726

SP - 5

EP - 25

JO - Journal of Fluid Mechanics

JF - Journal of Fluid Mechanics

SN - 0022-1120

ER -