TY - GEN
T1 - Optimal tail kinematicsunsteady vortexfor fish-likelattice methodlocomotion using the Unsteady Vortex Lattice Method
AU - Hussein, Ahmed A.
AU - Ragab, Saad
AU - Taha, Haithem E.
AU - Hajj, Muhammad R.
N1 - Publisher Copyright:
© 2018, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.
PY - 2018
Y1 - 2018
N2 - The design of fish-like swimmers depends on understanding the interaction between the fluid motion and the body dynamics of the fish. Towards this objective, the optimal motion of the fish – tail is sought. As a simplified assumptions, the base body is assumed to be an elliptic shape while the tail is approximated as an Euler-Bernoulli beam. Three cases for the tail motion are considered in this paper. The first, second, and the third case are defined respectively as rigid beam, flexible beam in which the flexible motion is assumed to be a linear superposition of simple harmonic motions that have the shapes as the first and the second normal modes of the tail, and a flexible beam in which the flexible motion of the tail is determined by solving the fluid-structure coupled problem. In all three cases the input to the tail is pitching rotation at the root is to be determined by minimizing the hydrodynamic power subjected to zero net thrust on the fish body. The unsteady hydrodynamic loads are calculated using the two-dimensional unsteady vortex lattice method. The aim of the study is to investigate the effect of the tail active and passive flexibility on the propulsive efficiency versus the rigid tail.
AB - The design of fish-like swimmers depends on understanding the interaction between the fluid motion and the body dynamics of the fish. Towards this objective, the optimal motion of the fish – tail is sought. As a simplified assumptions, the base body is assumed to be an elliptic shape while the tail is approximated as an Euler-Bernoulli beam. Three cases for the tail motion are considered in this paper. The first, second, and the third case are defined respectively as rigid beam, flexible beam in which the flexible motion is assumed to be a linear superposition of simple harmonic motions that have the shapes as the first and the second normal modes of the tail, and a flexible beam in which the flexible motion of the tail is determined by solving the fluid-structure coupled problem. In all three cases the input to the tail is pitching rotation at the root is to be determined by minimizing the hydrodynamic power subjected to zero net thrust on the fish body. The unsteady hydrodynamic loads are calculated using the two-dimensional unsteady vortex lattice method. The aim of the study is to investigate the effect of the tail active and passive flexibility on the propulsive efficiency versus the rigid tail.
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U2 - 10.2514/6.2018-0303
DO - 10.2514/6.2018-0303
M3 - Conference contribution
AN - SCOPUS:85141558752
SN - 9781624105241
T3 - AIAA Aerospace Sciences Meeting, 2018
BT - AIAA Aerospace Sciences Meeting
T2 - AIAA Aerospace Sciences Meeting, 2018
Y2 - 8 January 2018 through 12 January 2018
ER -