2021
Yin, Tingyun; Pavesi, Giorgio; Pei, Ji; Yuan, Shouqi
Numerical analysis of unsteady cloud cavitating flow around a 3D Clark-Y hydrofoil considering end-wall effects Journal Article
In: Ocean Engineering, vol. 219, iss. April 2020, pp. 103506, 2021, ISSN: 00298018.
Abstract | Links | BibTeX | Tags: Three-dimensional Hydrofoil, Transient characteristics, Unsteady Cloud Cavitation
@article{Yin2021b,
title = {Numerical analysis of unsteady cloud cavitating flow around a 3D Clark-Y hydrofoil considering end-wall effects},
author = {Tingyun Yin and Giorgio Pavesi and Ji Pei and Shouqi Yuan},
url = {https://www.sciencedirect.com/science/article/pii/S0029801820312762?utm_campaign=STMJ_AUTH_SERV_PUBLISHED&utm_medium=email&utm_acid=30163317&SIS_ID=&dgcid=STMJ_AUTH_SERV_PUBLISHED&CMX_ID=&utm_in=DM110556&utm_source=AC_ https://www.sciencedirect.com/scienc},
doi = {10.1016/j.oceaneng.2020.108369},
issn = {00298018},
year = {2021},
date = {2021-01-01},
journal = {Ocean Engineering},
volume = {219},
issue = {April 2020},
pages = {103506},
publisher = {Elsevier Ltd},
abstract = {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.},
keywords = {Three-dimensional Hydrofoil, Transient characteristics, Unsteady Cloud Cavitation},
pubstate = {published},
tppubtype = {article}
}
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.
Yin, Tingyun; Pavesi, Giorgio; Pei, Ji; Yuan, Shouqi; Cavazzini, Giovanna; Ardizzon, Guido
Lagrangian Analysis of Unsteady Partial Cavitating Flow Around a Three-Dimensional Hydrofoil Journal Article
In: Journal of Fluids Engineering, vol. 143, iss. 4 - April, pp. 1-11, 2021, ISSN: 0098-2202.
Abstract | Links | BibTeX | Tags: Lagrangian Analysis, Shedding frequencies, Three-dimensional Hydrofoil, Unsteady Cavitating Flow
@article{Yin2021c,
title = {Lagrangian Analysis of Unsteady Partial Cavitating Flow Around a Three-Dimensional Hydrofoil},
author = {Tingyun Yin and Giorgio Pavesi and Ji Pei and Shouqi Yuan and Giovanna Cavazzini and Guido Ardizzon},
url = {https://asmedigitalcollection.asme.org/fluidsengineering/article/143/4/041202/1091940/Lagrangian-Analysis-of-Unsteady-Partial-Cavitating},
doi = {10.1115/1.4049242},
issn = {0098-2202},
year = {2021},
date = {2021-01-01},
journal = {Journal of Fluids Engineering},
volume = {143},
issue = {4 - April},
pages = {1-11},
publisher = {American Society of Mechanical Engineers (ASME)},
abstract = {This study employs an incompressible homogeneous flow framework with a transport-equation-based cavitation model and shear stress transport turbulence model to successfully reproduce the unsteady cavitating flow around a three-dimensional hydrofoil. 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 23 ms. By monitoring the motions of the seeding trackers, growth-up of attached cavity and dynamic evolution of U-type cavity are clearly displayed, which indicating the trackers could serve as an effective tool to visualize the cavitating field. Repelling Lagrangian Coherent Structure (RLCS) is so complex that abundant flow patterns are highlighted, reflecting the intricacy of cavity development. The formation of cloud cavities is clearly characterized by the Attracting Lagrangian Coherent Structure (ALCS), where bumbling wave wrapping the whole shedding cavities indicates the rotating transform of cavities and stretching of the wave eyes shows the distortion of vortices. Generation of the re-entrant jet is considered to be not only associated with the adverse pressure gradient due to the positive attack angle, but also the contribution of cloud cavitating flow, based on the observation of a buffer zone between the attached and cloud cavities.},
keywords = {Lagrangian Analysis, Shedding frequencies, Three-dimensional Hydrofoil, Unsteady Cavitating Flow},
pubstate = {published},
tppubtype = {article}
}
This study employs an incompressible homogeneous flow framework with a transport-equation-based cavitation model and shear stress transport turbulence model to successfully reproduce the unsteady cavitating flow around a three-dimensional hydrofoil. 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 23 ms. By monitoring the motions of the seeding trackers, growth-up of attached cavity and dynamic evolution of U-type cavity are clearly displayed, which indicating the trackers could serve as an effective tool to visualize the cavitating field. Repelling Lagrangian Coherent Structure (RLCS) is so complex that abundant flow patterns are highlighted, reflecting the intricacy of cavity development. The formation of cloud cavities is clearly characterized by the Attracting Lagrangian Coherent Structure (ALCS), where bumbling wave wrapping the whole shedding cavities indicates the rotating transform of cavities and stretching of the wave eyes shows the distortion of vortices. Generation of the re-entrant jet is considered to be not only associated with the adverse pressure gradient due to the positive attack angle, but also the contribution of cloud cavitating flow, based on the observation of a buffer zone between the attached and cloud cavities.
