Cavitation Dynamics using Biofluidic Riblets and Beveled Trailing Edges on MHKF-180 Hydrofoils

Hydraulic systems often face serious problems due to cavitation, where bubbles form and collapse in fast-moving water, causing damage and reducing efficiency and stability. This issue is especially challenging for the MHKF-180 hydrofoil, a special blade used in marine energy systems like tidal turbines. Two major concerns for this hydrofoil are the formation of cavitation bubbles on its surface and the loud, high-pitched noise-known as hydrodynamic “singing” which comes from its blunt trailing edge. To address these challenges and in order to suppress cavitation, this research proposes a new, nature-inspired solution: adding Cav Edge Riblets (CER), which are tiny grooves similar to those found on shark skin, and reshaping the trailing edge of the hydrofoil with a 70-degree bevel. The design is evaluated at a high Reynolds number $Re = 1.35 \times 10^{6}$ using unsteady numerical simulations in ANSYS, employing the Zwart-Gerber-Belamri cavitation model coupled with the realizable $k-\epsilon$ turbulence scheme, focusing on flow dynamics at an angle of attack $\alpha$ of $8^{\circ}$. The results demonstrate significant progress in cavitation suppression: the CER-modified configuration achieves near complete suppression of cavity formation while significantly reducing turbulent kinetic energy. Furthermore, the beveled trailing edge design helps mitigate singing noise. We find that these modifications introduce predictable trade-offs in lift and drag coefficients, the overall hydrodynamic stability improvements are notable, particularly for high-speed and endurance critical applications where cavitation resistance is essential.