RT Journal Article
T1 Effects of inertia on the time-averaged propulsive performance of a pitching and heaving foil
A1 Fernández-Feria, Ramón
K1 Inercia (Mecánica)
K1 Mecánica de fluidos
AB The inertia may play an important role in the unsteady behavior of a flapping foil. Of particular relevance in forward flapping locomotion is how the foil inertia may affect its time-averaged propulsive performance. This is the question addressed bythe present study from a general, nonlinear formulation of the unsteady interaction with the surrounding fluid of a thin, flexible, two-dimensional and non-uniform foil undergoing prescribed pitching and heaving motion of any amplitude about an arbitrarypivot axis. For a rigid foil it is shown that, although the unsteady inertial forces and moments may be much larger than the unsteady aerodynamic forces and moments if the fluid density is much smaller than the foil density, the inertia does not affectthe cycle-averaged propulsive performance for harmonic pitching and heaving motion, independently of their amplitude. Inertia may affect only the cycle-averaged moment if the mean angle of attack is not zero, but without affecting the cycle-averaged powerinput, and therefore the propulsive efficiency. When a small flexural deflection of the foil is considered, although the cycle-averaged inertial thrust and lift also vanish for any amplitude of the pitching and heaving harmonic motion, the cycle-averaged power input does not. Thus, the foil inertia contributes through the moment and power to the timeaveraged propulsive performance for any flexural deflection of the foil, obtained her e analytically in terms of the trailing edge location for general pitching and heaving motion of any amplitude and phase and small flexural deflection amplitude. Simple analytical results are also provided for inertia dominated deflection, characterizing the conditions that minimize the power consumption. The results are valid for arbitrary chord-wise distribution of mass, thickness and (sufficiently large) stiffness of the foil.
PB Elsevier
YR 2023
FD 2023
LK https://hdl.handle.net/10630/26936
UL https://hdl.handle.net/10630/26936
LA eng
NO Fernandez-Feria. (2023). Effects of inertia on the time-averaged propulsive performance of a pitching and heaving foil. Journal of Fluids and Structures, 120. https://doi.org/10.1016/j.jfluidstructs.2023.103907
NO This research has been supported by the Junta de Andalucía, Spain through grant UMA18-FEDER-JA-047Funding for open access charge: Universidad de Málaga / CBUA
DS RIUMA. Repositorio Institucional de la Universidad de Málaga
RD 20 ene 2026