WAKE STRUCTURE AROUND MOVING ELASTIC AIRFOILS WITH PROJECTIONS AND THEIR CHARACTERISTICS OF DYNAMIC FORCES BY FLUID STRUCTURE INTERACTION SIMULATION

摘要

The flow around an elastic body is treated as a fluid-structure interaction (FSI), numerous fluid-structure coupled problems have been performed. Recently, two-way coupled analysis, which considers the fluid-structure interaction, has been performed extensively. In the present paper, we simulate a flow field around an elastic heaving flat plate with a variable surface shape and various Young's moduli and perform bidirectional coupling analysis using ANSYS 12.1/ANSYS-CFX 12.1. In the case of the results without projection, the vorticity that grows along the plate surface, rolled up from the trailing edge, and developed in the wake are dependent on Strouhal number, independent of the Young's modulus. However, in the case of the results with the projections, the vortex behaviors are different with the Young's modulus. At E = 3.53 [MPa], the projections effect on the vortex behavior and the dynamic thrust exhibit approximately the same tendency with or without a projection. On the other hand, at E - 10.0 [MPa], the projection effect has an impact on the vortex behavior and the dynamic thrust. The vorticity and the dynamic thrust of E = 10.0 [MPa] become smaller than that of E = 3.53 [MPa] because of strong effects from the projections of the heaving elastic plate.