Numerical investigation of unsteady cavitating turbulent flows around twisted hydrofoil from the Lagrangian viewpoint

• Published in: Journal of hydrodynamics. Series B Vol. 28; no. 4; pp. 709 - 712
• Main Author: 程怀玉 龙新平 季斌 祝叶 周加建
• Format: Journal Article
• Language: English
• Published: Singapore Elsevier Ltd 01.08.2016; Springer Singapore
• Subjects: cavitating flow; cavitation; CFD; Engineering; Engineering Fluid Dynamics; Hydrology/Water Resources; LCS; Letter; Lyapunov; Numerical and Computational Physics; Simulation; twisted hydrofoil; 扭曲; 拉格朗日; 数值研究; 湍流绕流; 空化模型; 翼型; 非稳态; CFD; cavitating flow; twisted hydrofoil; LCS; cavitation
• ISSN: 1001-6058; 1878-0342
• DOI: 10.1016/S1001-6058(16)60674-1

Unsteady cavitating turbulent flow around twisted hydrofoil is simulated with Zwart cavitation model combined with the filter-based density correction model (FBDCM). Numerical results simulated the entire process of the 3-D cavitation shedding including the re-entrant jet and side-entrant jet dynamics and were compared with the available experimental data. The distribution of finite-time Lyapunov exponent (FTLE) was used to analyze the 3-D behavior of the re-entrant jet from the Lagrangian viewpoint, which shows that it can significantly influence the particle trackers in the attached cavity. Further analysis indicates that the different flow behavior on the suction side with different attack angle can be identified with Lagrangian coherent structures (LCS). For the area with a large attack angle, the primary shedding modifies the flow pattern on the suction side. With the decrease in attack angle, the attached cavity tends to be steady, and LCS A is close to the upper wall. A further decrease in attack angle eliminates LCS A in the boundary layer. The FTLE distribution also indicates that the decreasing attack angle induces a thinner boundary layer along the foil surface on the suction side.