Large Eddy Simulation of Hydrodynamic Characteristics of Hydrofoils Based on Blow Suction Combined Jet

A unique flow control approach, blow suction combined jet (BSCJ), was presented to enhance the hydrodynamic performance of hydrofoils without the need of external energy resources. Utilizing the three-dimensional (3D) NACA0015 (National Advisory Committee for Aeronautics, NACA) foil as a case study, the orthogonal design methodology is employed to enhance the design of geometric and flow parameters, including the suction/blow point and the jet momentum coefficient. The fluid dynamics of the BSCJ foil at various angles of attack were numerically assessed using the large eddy simulation (LES) approach. The flow structures, encompassing vortex formations, pressure coefficients, and the impact of boundary layer velocity, were presented and evaluated to elucidate the control mechanism and influence of BSCJ. The simulation results indicate that the BSCJ primarily enhances the separation point of the rear wing surface by eliminating low-momentum fluid from the hydrofoil’s suction surface, thereby substantially augmenting the pressure differential across the hydrofoil and ultimately enhancing its hydrodynamic performance. The jet momentum coefficient is the primary determinant influencing the hydrodynamic performance of the hydrofoil, with best conditions attained when the suction slot is positioned at 0.25 C from the leading edge, the blowing slot at 0 C from the trailing edge, and the jet momentum coefficient is 0.1. The conclusions derived from the current study can offer theoretical advice for the future application of the BSCJ approach in underwater vehicles.