Numerical analysis of unsteady cloud cavitating flow around a 3D Clark-Y hydrofoil considering end-wall effects

• Published in: Ocean engineering 2021-01, Vol.219, p.108369, Article 108369
• Main Authors: Yin, Tingyun, Pavesi, Giorgio, Pei, Ji, Yuan, Shouqi
• Format: Article
• Language: English
• Subjects: Three-dimensional hydrofoil; Transient characteristics; Unsteady cloud cavitation
• ISSN: 0029-8018; 1873-5258
• DOI: 10.1016/j.oceaneng.2020.108369

This study employs an incompressible homogeneous flow framework with a transport equation based cavitation model and density corrected Shear Stress Transport (SST) k-ω turbulence model to successfully reproduce the unsteady cavitating flow around a 3D Clark-Y hydrofoil with an end wall. Cavity growth, development, and break-off during the periodic shedding process are adequately reproduced and match experimental observations. The predicted shedding frequency is very close to the experimental value of 43.48 Hz. The existence of an end wall brings about the generation and convection of wall-side cavity. Moreover, large horse-type cavity structure is captured, which agrees with experimental results. Cavities at the closure region easily detach from the main pocket part resulting in a secondary vortical structure. Differences between numerical and experimental lift are observed, however, similar to our previous findings, the experimental lift coefficient appears to correlate with the inverse of the second derivative of the total cavity volume. Based on the analysis of vorticity transportation, compressibility source occupies the highest contribution of vorticity transportation and is significantly higher than other two terms, which serves the promotion effect at the trailing region of growing attached cavity while inhibits the development of vorticity within the leading area. •Cavity growth, development, and break-off during the periodic shedding process were adequately reproduced.•Prediction of cavity motion matches well with experimental observations.•Coherence between lift coefficient and cavity volume was discussed.•Budget of vorticity transportation was discussed.