Viscous Fluid Structure Interaction Response of Composite Hydrofoils
Y. Liao, N. Garg, J. R. R. A. Martins, and Y. L. Young
Composite Structures, 212571–585, 2019
Composite materials are increasingly used in hydrodynamic lifting surfaces due to their higher specific strength and favorable fatigue properties. A set of parametric studies are performed to investigate the influence of fiber orientation on the vibration characteristics and load-dependent bend-twist coupled behavior of composite hydrofoils in viscous flow. A 3-D Reynolds-averaged Navier–Stokes (RANS) solver is coupled with a 3-D finite-element method (FEM) to predict the fluid–structure response of cantilevered composite hydrofoils made of unidirectional carbon fiber reinforced polymer (CFRP). Fiber orientation changes the modal characteristics of composite hydrofoils, as well as the hydroelastic response. The bending-up and nose-down material bend-twist coupling leads to lower hydrodynamic load coefficients with increasing flow speed, as well as delayed separation, stall, and static divergence. The opposite trend is observed when the fiber orientation results in a bending-up and nose-up material bend-twist coupling. Material failure index contours show that the fiber orientation affects the location of failure. These parametric studies provide guidance for future design and optimization of composite hydrodynamic lifting surfaces.