TY - JOUR
T1 - Fin sweep angle does not determine flapping propulsive performance
AU - Zurman-Nasution, Andhini N.
AU - Ganapathisubramani, Bharathram
AU - Weymouth, Gabriel D.
PY - 2021
Y1 - 2021
N2 - The importance of the leading-edge sweep angle of propulsive surfaces used by unsteady swimming and flying animals has been an issue of debate for many years, spurring studies in biology, engineering, and robotics with mixed conclusions. In this work, we provide results from three-dimensional simulations on single-planform finite foils undergoing tail-like (pitch-heave) and flipper-like (twist-roll) kinematics for a range of sweep angles covering a substantial portion of animals while carefully controlling all other parameters. Our primary finding is the negligible 0.043 maximum correlation between the sweep angle and the propulsive force and power for both tail-like and flipper-like motions. This indicates that fish tails and mammal flukes with similar range and size can have a large range of potential sweep angles without significant negative propulsive impact. Although there is a slight benefit to avoiding large sweep angles, this is easily compensated by adjusting the fin's motion parameters such as flapping frequency, amplitude and maximum angle of attack to gain higher thrust and efficiency.
AB - The importance of the leading-edge sweep angle of propulsive surfaces used by unsteady swimming and flying animals has been an issue of debate for many years, spurring studies in biology, engineering, and robotics with mixed conclusions. In this work, we provide results from three-dimensional simulations on single-planform finite foils undergoing tail-like (pitch-heave) and flipper-like (twist-roll) kinematics for a range of sweep angles covering a substantial portion of animals while carefully controlling all other parameters. Our primary finding is the negligible 0.043 maximum correlation between the sweep angle and the propulsive force and power for both tail-like and flipper-like motions. This indicates that fish tails and mammal flukes with similar range and size can have a large range of potential sweep angles without significant negative propulsive impact. Although there is a slight benefit to avoiding large sweep angles, this is easily compensated by adjusting the fin's motion parameters such as flapping frequency, amplitude and maximum angle of attack to gain higher thrust and efficiency.
KW - bio-mechanical evolution
KW - biolocomotion
KW - flapping foils
UR - http://www.scopus.com/inward/record.url?scp=85106893490&partnerID=8YFLogxK
U2 - 10.1098/rsif.2021.0174
DO - 10.1098/rsif.2021.0174
M3 - Article
C2 - 34034533
AN - SCOPUS:85106893490
SN - 1742-5689
VL - 18
JO - Journal of the Royal Society Interface
JF - Journal of the Royal Society Interface
IS - 178
M1 - 2021174
ER -