S-Space College of Engineering/Engineering Practice School (공과대학/대학원) Dept. of Mechanical Aerospace Engineering (기계항공공학부) Others_기계항공공학부
FSI를 활용한 2차원 곤충날개 주위 유동장 해석
NUMERICAL STUDY ON THE UNSTEADY FLOW PHYSICS OF INSTECTS" FLAPPING FLIGHT USING FLUID-STRUCTURE INTERACTION
- 이근배; 김진호; 김종암
- Issue Date
- 한국전산유체공학회 2009년도 추계학술대회 논문집, pp. 151-158
- 공학; 곤충비행; Insect Flight; 유체-구조 연성해석; Fluid-Structure Interaction; 추력효율성; Propulsive efficiency; 비정상유동; Unsteady flow; 전산유체역학; CFD
- To implement the insects" flapping flight for developing flapping MAVs(micro air vehicles), the unsteady flow characteristics of the insects" forward flight is investigated In this paper, two-dimensional FSI(Fluid-Structure Interaction) simulations are conducted to examine realistic flow features of insects" flapping flight and to examine the flexibility effects of the insect"s wing. The unsteady incompressible Navier-Stokes equations with an artificial compressibility method are implemented as the fluid module while the dynamic finite element equations using a direct integration method are employed as the solid module. In order to exchange physical information to each module, the common refinement method is employed as the data transfer method Also, a simple and efficient dynamic grid deformation technique based on Delaunay graph mapping is used to deform computational grids.
Compared to the earlier researches of two-dimensional rigid wing simulations, key physical phenomena and flow patterns such as vortex pairing and vortex staying can still be observed. For example, lift is mainly generated during downstroke motion by high effective angle of attack caused by translation and lagging motion. A large amount of thrust is generated abruptly at the end of upstroke motion. However, the quantitative aspect of flow field is somewhat different. A flexible wing generates more thrust but less lift than a rigid wing. This is because the net force acting on wing surface is split into two directions due to structural flexibility. As a consequence, thrust and propulsive efficiency was enhanced considerably compared to a rigid wing. From these numerical simulations, it is seen that the wing flexibility yields a significant impact on aerodynamic characteristics.