Numerical investigation of the deformation characteristics of a composite hydrofoil with different ply angles

The main object of this paper is to investigate the deformation characteristics of a composite hydrofoil via numerical simulations. The aims of this paper are to 1) validate the 3D numerical simulation method with fluid-structure interaction modeling of composite materials, 2) investigate the effects of ply angles on hydrodynamics forces and structural deformations of the composite hydrofoil and 3) investigate the relationship between tip twist angle(β) and properties of the composite hydrofoil based on the Classical Laminate Theory analysis. Numerical results are presented for a modified NACA0009 composite hydrofoil, which has an unswept trapezoidal planform of aspect ratio 3.33. The fluid-structure coupling method is proposed and validated with the experiment data by Zarruk et al.[7]. The hydrodynamic forces and structural deformations of the composite hydrofoil with different ply angles have been investigated at Re = 1 × 106 and initial angle of attack α = 6°. The results show that lift and drag coefficients and tip twist angle decrease as the ply angle increases, from negative ply angle to positive ply angle. The twist angle plays a significant role in lift and drag coefficients, as well as the distribution of normalized lift and drag along spanwise direction. It should be noted that the composite hydrofoil with larger deformation is more probable to fail according to the inverse reserve factor with Tsai-Wu criteria. The expression on elements of bending stiffness matrices D has been derived to estimate tip twist angle.