Multidisciplinary Design Optimization Of Flapping-wing Micro Air Viecle

Micro air vehicle (MAV) possesses many advantages including small in size, light in weight and good in stealth, has a very bright future in military and civilian fields, which make it a hotspot in scientific and aerospace engineering research. Birds can carry out various complicated maneuverable flight with only a pair of flapping wings, and can fly a very long distance by very little energy. All flyable creatures in the nature world fly by flapping wings. Flapping Wings MAV can provide both lift and thrust with only a set of Flapping Wing system, it also has a very good maneuverability. Flapping Wings MAV does not need propeller or jet engine for flight, which makes its structure largely simplified and its weight decreased. These are the particular advantages of Flapping Wings MAV compared with fixed wing and rotor ones. Therefore, Flapping Wings MAV should make an important role in the research of the new concept flyer. How to optimize the general performance of Flapping Wings MAV becomes an important research direction.Firstly, in this paper, the flight mode, flight theory and kinetic mode of flapping wings of the flying creatures are analyzed, which provide a theory and biomimetic basis for designing and optimizing the flapping wings MAV.In designing and optimizing the flapping wings MAV, aerodynamic performances of the flapping wings MAV becomes the most basal problems; the aerodynamic performances of flapping wing under different kinetic parameters becomes the basement for designing and optimizing the flapping wings MAV. In this paper, based on the"silver wing"flapping wings MAV designed by the NUAA MAV research center, a flexible flapping Wing model is built, and the three dimensional unsteady low Reynolds number flow of this model is numerically simulated. Also, the influences of different parameters on the aerodynamic performances of flapping wing are studied. This research establishes a basis for multidisciplinary design optimization of flapping wing MAV.Multidisciplinary design optimization (MDO) is an effective way for solving and optimizing complicated engineering system and multidisciplinary dynamic influence. It was first promoted by AIAA in America in the early 1990s. its main idea is to integrate the knowledge of every subject in the whole process of designing a complicated system, and fully take into consideration the interferences and coupling effect, use effective design/optimization strategy and distributed computer network managing and organizing the design process of the whole system, then take advantage of the synergetic effect interacted among the subjects gaining the overall optimal solution of the system. The most standout advantage of MDO is to tap the design potential by fully take into consideration the interference and coupling effect of the subjects. On the other hand, MDO also has the advantages such as shortening the design cycle, decreasing the design cost, etc.In this paper, some MDO methods are studied, and then a flapping wing MAV is optimized by analyzing the related subjects of flapping wing MAV and by using MDO methods. Also, a flight test is carried out as the flapping MAV is redesigned based on the optimizated parameters. All the obtained results indicate that the optimization shows great improvement on aerodynamic performances of flapping wing MAV.