Chinese Journal of Theoretical and Applied Mechanics ›› 2019, Vol. 51 ›› Issue (6): 1752-1760.DOI: 10.6052/0459-1879-19-222

• Fluid Mechanics • Previous Articles     Next Articles

NUMERICAL SIMULATION AND ANALYSIS OF ACTIVE JET CONTROL OF HYDROFOIL CAVITATION1)

Wang Wei(),Tang Tao,Lu Shengpeng,Zhang Qingdian,Wang Xiaofang   

  1. Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, Dalian University of Technology, Dalian 116024, China
  • Received:2019-08-19 Accepted:2019-10-17 Online:2019-10-21 Published:2019-12-26
  • Contact: Wang Wei

Abstract:

In order to improve the cavitation characteristics of the flow field on the suction side of the hydrofoil under high-speed flow conditions, a method of active water jet arranged on the suction side is proposed to control the flow around the hydrofoil. Based on a filter-based density correction turbulence model combined with Zwart-Gerber-Belamri cavitation model, the influence of the water jet on the cavitation and hydrodynamic characteristics of the hydrofoil is analyzed when the cavitation number is 0.83, the angle of attack is 8$^\circ$ and the water jet is 0.19$c$ from the foil leading edge. The intensity of the re-entrant jet is analyzed quantitatively to explore the relationship between the re-entrant jet and the cavitation characteristics of the flow field. The numerical results show that the time-average cavity volume on the suction side of the hydrofoil with jet is 14/15 smaller than that of the original hydrofoil, which indicate that the water jet can significantly weaken the development of cavitation, and thus the cavitation pattern in the flow field transforms from cloud cavitation to sheet cavitation. Moreover, the water injection greatly improves the hydrodynamic performance of the hydrofoil. The lift to drag ratio of the hydrofoil increases by 22.9${\%}$ compared with that of the original hydrofoil, meanwhile, and the shedding frequency of the cavitation decreases by 26.2${\%}$, and the amplitude caused by the shedding of the cavitation decreases by 9.1${\%}$. The water jet shrinks low pressure area on the suction side sharply and reduces the reverse pressure difference of flow in the vicinity of the hydrofoil, as a result, intensity of the re-entrant jet declined. The water injection also thins the boundary layer which enhances the anti-reverse pressure gradient capability of the flow and then blocks the re-entrant jet. Those explain the mechanism of cavitation flow control by active water injection.

Key words: cavitation suppression, active injection, re-entrant jet, hydrodynamic performance, flow control

CLC Number: