TY - JOUR

T1 - Coupling performance of two tandem and side-by-side inverted piezoelectric flags in an oscillating flow

AU - Mazharmanesh, Soudeh

AU - Young, John

AU - Tian, Fang Bao

AU - Ravi, Sridhar

AU - Lai, Joseph C.S.

N1 - Funding Information:
This research was undertaken with the assistance of resources from the National Computational Infrastructure (NCI), which is supported by the Australian Government . S.M. wishes to gratefully acknowledge the support of the University of New South Wales Tuition Fee Scholarship, Australia for the pursuit of this study. F.-B.T. is the recipient of an Australian Research Council Discovery Early Career Research Award (project number DE160101098 ). S.R. acknowledges the support of Asian Office of Aerospace Research and Development (grant nos. FA2386-19-1-4066 and FA2386-20-1-4084 ) and Office of Naval Research Global, United States (grant nos. N62909-20-1-2088 ).
Publisher Copyright:
© 2023 Elsevier Ltd

PY - 2023/5

Y1 - 2023/5

N2 - The flow-induced vibration characteristics and energy extraction performance of two flexible inverted piezoelectric flags arranged in tandem and side-by-side configurations in an oscillating flow are studied. An immersed boundary-lattice Boltzmann method is employed for Reynolds number of 100, mass ratio of 2.9 and non-dimensional bending stiffness of 0.26 which correspond to the maximum flapping amplitude for a single inverted flag in a uniform flow. 2D simulations are conducted by varying the ratio R of the frequency of the oscillating flow to the fundamental natural frequency of the flag and the horizontal velocity amplitude (Au) of the flow. Three coupling regimes at Au=0.5 are identified for both tandem and side-by-side flags: chaotic oscillations regime I (0.1≤R≤1), large periodic and symmetric oscillation regime IIa1.1≤R≤1.5andIIb(2.1≤R≤3.0), and small periodic and asymmetric oscillation regime III(1.6≤R≤2). The maximum mean electrical power coefficient C¯P occurs in regime IIa at R=1.5 with, α (piezo-mechanical coupling parameter) = 0.5, and β (piezo-electric tuning parameter) = 1.5. C¯P is 0.1 for a tandem upstream flag, 0.068 for the tandem downstream flag and 0.1 for both side-by-side flags, and is respectively 120%, 300% and 213%, higher than that of the corresponding flag in the uniform flow. This improvement is attributed to the higher flapping angular amplitude (180°), the higher ratio of the flapping frequency of the flags to the oscillating frequency of the flow (virtually constant at 0.5), and constructive vortex interaction in regime IIa.

AB - The flow-induced vibration characteristics and energy extraction performance of two flexible inverted piezoelectric flags arranged in tandem and side-by-side configurations in an oscillating flow are studied. An immersed boundary-lattice Boltzmann method is employed for Reynolds number of 100, mass ratio of 2.9 and non-dimensional bending stiffness of 0.26 which correspond to the maximum flapping amplitude for a single inverted flag in a uniform flow. 2D simulations are conducted by varying the ratio R of the frequency of the oscillating flow to the fundamental natural frequency of the flag and the horizontal velocity amplitude (Au) of the flow. Three coupling regimes at Au=0.5 are identified for both tandem and side-by-side flags: chaotic oscillations regime I (0.1≤R≤1), large periodic and symmetric oscillation regime IIa1.1≤R≤1.5andIIb(2.1≤R≤3.0), and small periodic and asymmetric oscillation regime III(1.6≤R≤2). The maximum mean electrical power coefficient C¯P occurs in regime IIa at R=1.5 with, α (piezo-mechanical coupling parameter) = 0.5, and β (piezo-electric tuning parameter) = 1.5. C¯P is 0.1 for a tandem upstream flag, 0.068 for the tandem downstream flag and 0.1 for both side-by-side flags, and is respectively 120%, 300% and 213%, higher than that of the corresponding flag in the uniform flow. This improvement is attributed to the higher flapping angular amplitude (180°), the higher ratio of the flapping frequency of the flags to the oscillating frequency of the flow (virtually constant at 0.5), and constructive vortex interaction in regime IIa.

KW - Fluid–structure interaction

KW - Immersed boundary-lattice Boltzmann method

KW - Inverted piezoelectric flags

KW - Oscillating flow

UR - http://www.scopus.com/inward/record.url?scp=85151256187&partnerID=8YFLogxK

U2 - 10.1016/j.jfluidstructs.2023.103874

DO - 10.1016/j.jfluidstructs.2023.103874

M3 - Article

AN - SCOPUS:85151256187

SN - 0889-9746

VL - 119

JO - Journal of Fluids and Structures

JF - Journal of Fluids and Structures

M1 - 103874

ER -