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This content will become publicly available on November 17, 2025

Title: Hydrodynamics of Shrimp Swimming: Spread-Out Morphing of Pleopods in Power Stroke
Abstract Shrimps locomote through water using five pairs of appendages known as pleopods, which beat in a coordinated metachronal motion. Each pleopods consists of two membranous rami, a medial endopod and lateral exopod whose edges are lined with fine hair-like setae. Because of their close spacing and density, the setae act as an impermeable membrane. During swimming, each pleopod executes a power stroke, propelling water backward, followed by a recovery stroke to reset its position. During the power stroke, the exopods, endopods, and setae spread out, forming a propulsor with a larger area. In contrast, the rami close and overlap during the recovery stroke, reducing the effective area. In this study, we simulate natural shrimp swimming based on high-speed recordings under Reynolds number (Re) of 1980, using an in-house computational fluid dynamics (CFD) solver. We compared a model based on a natural swimming shrimp with a model with pleopod area fixed at the maximum area. Our results reveal that the model incorporating spread-out motion achieves a notable reduction of 49.84% in cycle-averaged hydrodynamic power while sacrificing only 23% of cycle-averaged thrust when compared to the fixed-pleopod area model. Furthermore, the effect of spread-out motion decreases the cost of transportation by 41.72% through reducing body drag by 12%. Additionally, our analysis observed the presence of a high-speed zone behind the second pleopod during stroke motion, particularly near the tangent plane of the lowest tip trajectory, and a low-speed zone in front of that pleopods.  more » « less
Award ID(s):
2451990
PAR ID:
10613166
Author(s) / Creator(s):
; ; ;
Publisher / Repository:
American Society of Mechanical Engineers
Date Published:
ISBN:
978-0-7918-8866-7
Format(s):
Medium: X
Location:
Portland, Oregon, USA
Sponsoring Org:
National Science Foundation
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