Numerical Study on the Influence of Plasma Actuation on the Cavitation Characteristics of Hydrofoil

Abstract

In order to investigate the influence of plasma actuation on cavitation in the flow field around a hydrofoil, the RNG k-ε turbulence model with density correction, the Schnerr–Sauer cavitation model, and the plasma phenomenological model were used to analyze the influence of forward and reverse plasma actuation on the cavitation characteristics of the NACA66(MOD) hydrofoil at an angle of attack of 8. The cavitation number of the incoming flow was 0.99. The results showed that under the positive excitation condition, the cavitation volume on the suction side of the hydrofoil was reduced by about 30%, and the time-averaged lift–drag ratio was reduced by about 5%, which had little influence on the re-entrant jet, vortex and shear flow. Therefore, the cavitation suppression effect on the hydrofoil flow field was weak. Under the condition of reverse actuation, the volume of cavitation on the suction side of the hydrofoil was reduced by about 87%, and the time-averaged lift–drag ratio was increased by about 21%, which effectively worsened the development conditions of cavitation. By greatly reducing the intensity of the re-entrant jet and eliminating the vortex and shear flow in the flow field, cavitation in the hydrofoil flow field was obviously suppressed. This shows that reasonable plasma actuation is an effective means to control hydrofoil cavitation.

Keywords

• cavitation
• hydrofoil
• plasma actuation
• re-entrant jet
• vortex structure