TY - JOUR
T1 - Design optimization of flapping ornithopters
T2 - The pterosaur replica in forward flight
AU - Zakaria, Mohamed Y.
AU - Taha, Haithem E.
AU - Hajj, Muhammad R.
N1 - Publisher Copyright:
Copyright © 2015 by MohamedY. Zakaria. Published by the American Institute of Aeronautics and Astronautics, Inc.
PY - 2016
Y1 - 2016
N2 - There has been a recent interest to explore the shape and kinematics parameters of distinct pterosaurs from their fossil records. Clearly, far more evidence is needed to understand the nuances of dinosaurs flight. A multiobjective aerodynamic optimization problem of the wing kinematics and planform of a pterosaur replica ornithopter designed by Aerovironment is performed. Objective functions include minimization of the required cycle-averaged aerodynamic power and maximization of the propulsive efficiency. It is found that inclusion of the inertial power requirements is necessary for a physical and proper formulation of the optimization problem. Furthermore, the mere addition of the inertial power requirements is not enough to obtain reasonable results. Rather, one has to consider a partial (or even zero) elastic energy storage. The minimum power kinematic parameters closely match those of the previously designed pterosaur replica. Nevertheless, the obtained efficiency for such a design (minimum power) is 10%, which is considerably lower than the maximum possible efficiency for the used planform (40%). Furthermore, the optimized planform for maximum efficiency of the pterosaur yields to an increase in the propulsive efficiency by 6%.
AB - There has been a recent interest to explore the shape and kinematics parameters of distinct pterosaurs from their fossil records. Clearly, far more evidence is needed to understand the nuances of dinosaurs flight. A multiobjective aerodynamic optimization problem of the wing kinematics and planform of a pterosaur replica ornithopter designed by Aerovironment is performed. Objective functions include minimization of the required cycle-averaged aerodynamic power and maximization of the propulsive efficiency. It is found that inclusion of the inertial power requirements is necessary for a physical and proper formulation of the optimization problem. Furthermore, the mere addition of the inertial power requirements is not enough to obtain reasonable results. Rather, one has to consider a partial (or even zero) elastic energy storage. The minimum power kinematic parameters closely match those of the previously designed pterosaur replica. Nevertheless, the obtained efficiency for such a design (minimum power) is 10%, which is considerably lower than the maximum possible efficiency for the used planform (40%). Furthermore, the optimized planform for maximum efficiency of the pterosaur yields to an increase in the propulsive efficiency by 6%.
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U2 - 10.2514/1.C033154
DO - 10.2514/1.C033154
M3 - Article
AN - SCOPUS:84960540475
SN - 0021-8669
VL - 53
SP - 48
EP - 59
JO - Journal of Aircraft
JF - Journal of Aircraft
IS - 1
ER -