Perpustakaan Digital ITB

Mimicking of bird flight to obtain a geometry of flapping wing aerial vehicle which have higher thrust requires the understanding of flapping motion behaviour and how to model the flapping motion. Flapping wing natural morphology, especially on bird, has unique material properties characteristic. Bird wing are naturally sturdier and heavier in near leading edge and gradually decrease as it goes to trailing edge. This morphological feature are going to be represented here as simpler feature, accommodated via discrete discrepancy. And due to its complicated nature, it is appropriate to decouple between varying parameters. This discretization however, have a huge drawback because it needs a lot of cases. This study explores variation of air speed, discrepancy location, material Young’s modulus and density, while flapping frequency and geometry are define at first at kept same throughout the variation. Pigeon bird is taken as a reference data for modelling the flapping wing. Structure morphologies with various material properties of the flapping wing such as density and Young’s modulus across the wing planform are modelled to mimic the bird wing topology using the material of polystyrenes family. The analysis of the flapping motion model is carried out using two-way Fluid Structure Interaction method based the solution of unsteady Reynold Averaged Navier-Stokes equations and transient Finite Element method to find the flapping wing behaviour during flapping cycle. In addition, even though a resonance between fluid flow and structure is often neglected, when it happened it could have catastrophic effect on wing integrity. Therefore, acoustic model is carried out to find out if it is safe to implement these case or not, which frequency is varied across the cases. Results and analysis of modelling of flapping shows that heavier and weaker rear part is beneficial within this study cases.