Reduced-order modeling of unsteady aerodynamics of a flapping wing based on the Volterra theory

Flapping flight mechanisms offers a power-efficient and highly manoeuvrable basis for the development of micro air vehicles. The aerodynamic knowledge and prediction tools of the flapping wing are quite important for the design of micro air vehicles. In this paper, the unsteady aerodynamics of a flapping wing is investigated by numerical simulations and the generation of reduced-order model based on the Volterra theory for predicting the unsteady aerodynamic of a flapping wing is described. The three dimensional aerodynamic calculation is performed by solving the unsteady Reynolds-averaged NavierStokes equations and the user-defined functions were employed to simulate the flapping motion. The training maneuver is a flapping motion with a linearly increasing flapping frequency. Based on the Volterra theory and numerical simulation results, a reduced-order model is generated to predict the unsteady aerodynamics of a flapping wing. The system identification method is employed to generate the Volterra theory reduced-order model. The results show that the Volterra theory reduced-order model agrees well with the training data and the Volterra theory reduced-order model works well to predict the unsteady aerodynamics of a flapping wing. (C) 2017 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license.