Numerical simulation of fluid-structure interaction of a moving flexible foil

The hybrid Cartesian/immersed boundary method is applied to fluid-structure interaction of a moving flexible foil. A new algorithm is suggested to classify immersed boundary nodes based on edges crossing a boundary. Velocity vectors are reconstructed at the immersed boundary nodes by using the interpolation along a local normal line to the boundary. For eliminating pressure reconstruction, the hybrid staggered/non-staggered grid method is adapted. The deformation of an elastic body is modeled based on dynamic thin-plate theory. To validate the developed code first, free rotation of a foil in a channel flow is simulated and the computed angular motion is compared with other computational results. The code is then applied to the fluid-structure interaction of a moving flexible foil which undergoes large deformation due to the fluid loading caused by horizontal sinusoidal motion. It has been shown that the moving flexible foil can generate much larger vertical force than the corresponding rigid foil and the vertical force can be attributed to the downward fluid jet due to the alternating tail deflection. This paper was recommended for publication in revised form by Associate Editor Haecheon Choi Sangmook Shin received his B.S. and M.S. degrees in Naval Architecture from Seoul National University, Korea in 1989 and 1991, respectively. He received his Ph.D. degree in Aerospace Engineering from Virginia Tech, USA in 2001. He is currently an Assistant Professor at Department of Naval Architecture and Marine Systems Engineering at Pukyong National University in Busan, Korea. His research interests include fluid-structure interaction, unstructured grid method, internal wave, and two-phase flow. Hyoung Tae Kim received the B.S. and M.S. degrees in Naval Architecture from Seoul National University in 1979 and 1981, respectively and the Ph.D. degree in Mechanical Engineering from University of Iowa, U.S.A. in 1989. Dr. Kim is currently a Professor at the Department of Naval Architecture & Ocean Engineering at Chungnam National University, Korea. His research interests are in the area of Ship Hydrodynamics, CFD calculations of turbulent flows around ships and propellers, and human-powered and solar boat design.