Numerical Investigation on the Effect of Asymmetry of Flow Velocity on the Wake Vortex of Hydrofoils

The Karman vortex street is a common flow phenomenon. In hydraulic machinery, it usually located downstream of the guide vanes and runner blades, which reduces performance may also cause fatigue damage to structure. latest research suggested that difference in velocity gradient on each side blade trailing edge have significant impact strength wake vortex. current work aims verify above conclusion further explore influence asymmetry A numerical model with ratio, α, between two sides hydrofoil as only variable was designed, characteristics were solved by computational fluid dynamics (CFD) method based finite volume. unsteady Reynolds-average Navier–Stokes (URANS) equations numerically coupling transitional shear-stress transport (SST) turbulence model. results showed increase shedding frequency decreased first, then increased after reaching critical ratio αc1 ≈ 1.4. intensity first gradually decreased, suddenly disappeared αc2 2.2. value affected thickness edge, Reynolds number. Besides, effectiveness trailing-edge trimming. This can provide references for design machinery other submerged structures.