Experimental study on the lift generated by a flapping rotary wing applied in a micro air vehicle

Abstract

An experimental study was conducted to further validate whether the newly proposed flapping rotary wing is suitable for micro air vehicle design. First, the effects of two main kinematical parameters (flapping frequency and initial angle of attack) of flapping rotary wing on lift generation were discussed. It was found that a higher lift can be generated by flapping rotary wing through increasing flapping frequency at a proper initial angle of attack. Second, effect of coupled flapping motion with rotating motion on lift generation was analyzed. It is important that a larger lift was generated by flapping rotary wing than the superposition lifts from purely flapping and purely rotating motions when the initial angle of attack was less than a critical value. Finally, the comparison of the capability of lift generation from the flapping rotary wing and conventional rotary wing was given. It was indicated that the lift from flapping rotary wing was larger than that from conventional rotary wing in the range of Reynolds number from 2600 to 5000 as long as Strouhal number was determined appropriately. The present work suggests that flapping rotary wing may be a feasible and promising wing layout used in the design of micro air vehicle in terms of lift generation.

Experimental Validation on Lift Increment of a Flapping Rotary Wing with Boring-hole Design

“…The mean lift at different α are shown in Fig.3. It is obvious that the rule of L varied with was the same as the result of previous studies [1,2,5]. A remarkable benefit in L increment of the perforated wing was found: when α is less than 15°, the perforated wing has a larger L in the range of flapping frequency.…”

“…As a new layout applied in MAV, the flapping rotary wing layouts combined the advantages of rotary-wing and flapping-wing was put forward [1], which have been investigated extensively by experimental and computational fluid dynamics (CFD) methods [2,3,4]. Compared with the conventional layouts of MAV, the flapping rotary wing can generate a larger lift under the action of the effect of coupled flapping motion and rotary motion [5]. Besides, the flapping rotary wing not only keeps the high efficiency in low Reynolds number (Re), but also can hover easily [6].…”

“…Besides, the flapping rotary wing not only keeps the high efficiency in low Reynolds number (Re), but also can hover easily [6]. In spite of this, an obvious flaw for lift generation exists in the course when wing flaps up [2,5]. Based on the similarity in wing motion and mechanism of lift generation, the same problem also exists in flapping-wing MAV and has been solved effectively by boring holes on the wing [7].…”

“…In previous study, it is shown that initial angle of attack (α), the flapping frequency (f) and the lift acting on the model are three important variables which need to be measured accurately [5]. In test, the initial angle of attack was set manually by changing the gaskets in the fixture.…”

Functional morphology and structural characteristics of wings of the ladybird beetle,Coccinella septempunctata(L.)

“…Most of these excellent performance features have been extensively studied with the goal of enhancing bio-structure features applicable for the design of a micro air vehicle (Kummari et al, 2010;Zhou et al, 2014;Guo et al, 2012). Significant advances have been made in understanding the insect wing geometric structure, material characteristics, flying mechanism, controlling mode and bionic wing design Rajabi et al, 2015;Wang and Zhong, 2014).…”