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Title: Hydrodynamics of body–body interactions in dense synchronous elongated fish schools
Mechanisms for hydrodynamic benefit via fluid interactions in large planar fish schools ( n ≥ 10) are investigated by two-dimensional numerical simulations of carangiform fish swimming. It is observed that the average swimming efficiency of the 10-fish school is increased by 30% over a single swimmer, along with a thrust production improvement of 114%. The performance and flow analyses characterize the associated hydrodynamic interaction mechanisms in large dense schools leading to enhanced performance. First, anterior body suction arises from the proximity of the suction side of the flapping tail to the head of the following fish. Next, the block effect is observed as another fish body blocks the flow behind a fish. Finally, the wall effect enhances the flow of momentum downstream where the body of a neighboring fish acts as a wall for the flapping of a fish tail moving toward it. Because these primary body–body interactions are based on the arrangement of surrounding fish, a classification of the individual fish within the school is presented based on the intra-fish interactions and is reflected in the performance of the individuals. It is shown that the school can be separated as front fish, middle fish, edge fish, and back fish based on the geometric position, performance, and wake characteristics. Finally, groupings and mechanisms observed are proven to be consistent over a range of Reynolds numbers and school arrangements.  more » « less
Award ID(s):
1931929
NSF-PAR ID:
10473219
Author(s) / Creator(s):
; ; ;
Publisher / Repository:
AIP Publishing, Physics of Fluids
Date Published:
Journal Name:
Physics of Fluids
Volume:
35
Issue:
4
ISSN:
1070-6631
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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