2026
Yin, Tingyun; Pavesi, Giorgio
Numerical investigation of transient sheet/cloud cavitating flow around hydrofoil via incompressible and compressible methods Journal Article
In: OCEAN ENGINEERING, vol. 343, 2026.
Abstract | Links | BibTeX | Tags: Cavitation, CFD, CFD simulation, Compressible method, Hydrofoil, Incompressible method
@article{<LineBreak> 11577_3586598,
title = {Numerical investigation of transient sheet/cloud cavitating flow around hydrofoil via incompressible and compressible methods},
author = {Tingyun Yin and Giorgio Pavesi},
doi = {10.1016/j.oceaneng.2025.123271},
year = {2026},
date = {2026-01-01},
urldate = {2026-01-01},
journal = {OCEAN ENGINEERING},
volume = {343},
publisher = {PERGAMON-ELSEVIER SCIENCE LTD},
abstract = {This study compares two numerical analyses of dynamic cavitating flow from a sheet to a cloud considering both incompressible and compressibility models. In the incompressible simulation, the densities of the liquid and vapor remain constant. However, in the compressible case, the Tait equation of state and the ideal gas equation of state are used to characterize the two density attributes. The results demonstrate that the development of cavitation morphology can be effectively replicated using two methods. The predicted frequency of cloud shedding utilizing the compressible methodology is lower than that of the incompressible technique, exhibiting a disparity of around 31.40 %. However, the time-averaged force coefficients predicted by the two techniques are highly similar. The research conducted on the destabilization of sheet bubbles indicates that the condensation shock that is triggered by the inertia exerts a dominant influence on the local flow field. The backward flow beneath the sheet bubble is not the cause, but rather the outcome. Pressure pulses generated propagate in all directions as the cloud bubble above the hydrofoil surface collapses. Thus, pressure surges can have a substantial impact on hydraulic performance.},
keywords = {Cavitation, CFD, CFD simulation, Compressible method, Hydrofoil, Incompressible method},
pubstate = {published},
tppubtype = {article}
}
This study compares two numerical analyses of dynamic cavitating flow from a sheet to a cloud considering both incompressible and compressibility models. In the incompressible simulation, the densities of the liquid and vapor remain constant. However, in the compressible case, the Tait equation of state and the ideal gas equation of state are used to characterize the two density attributes. The results demonstrate that the development of cavitation morphology can be effectively replicated using two methods. The predicted frequency of cloud shedding utilizing the compressible methodology is lower than that of the incompressible technique, exhibiting a disparity of around 31.40 %. However, the time-averaged force coefficients predicted by the two techniques are highly similar. The research conducted on the destabilization of sheet bubbles indicates that the condensation shock that is triggered by the inertia exerts a dominant influence on the local flow field. The backward flow beneath the sheet bubble is not the cause, but rather the outcome. Pressure pulses generated propagate in all directions as the cloud bubble above the hydrofoil surface collapses. Thus, pressure surges can have a substantial impact on hydraulic performance.
2025
Zhao, Jiantao; Pei, Ji; Wang, Zhongsheng; Zhang, Benying; Wang, Wenjie; Gan, Xingcheng; Pavesi, Giorgio
In: Energy, vol. 328, 2025, ISSN: 18736785.
Abstract | Links | BibTeX | Tags: Approximate model, CFD simulation, Energy efficiency enhancement, Flow diagnosis, Inverse Design, Multistage Centrifugal Pump
@article{Zhao2025,
title = {Energy efficiency optimization of multistage centrifugal pumps based on blade loading control: Insights into flow instability suppression mechanism},
author = {Jiantao Zhao and Ji Pei and Zhongsheng Wang and Benying Zhang and Wenjie Wang and Xingcheng Gan and Giorgio Pavesi},
doi = {10.1016/j.energy.2025.136586},
issn = {18736785},
year = {2025},
date = {2025-01-01},
journal = {Energy},
volume = {328},
publisher = {Elsevier Ltd},
abstract = {Multistage centrifugal pumps (MSCPs) are critical for high-pressure fluid transport, and their hydraulic efficiency directly affects the energy consumption of energy systems. However, flow instabilities result in substantial energy loss. This study employed blade loading theory, which is closely related to the flow field state, to achieve a parametric blade design. A non-expert-driven optimization framework was constructed by integrating the Metamodel of Optimal Prognosis (MoP) with the technique for order of preference by similarity to the ideal solution based on the entropy weight method (EW-TOPSIS). The optimization objective was to improve the hydraulic efficiency of the pump in the preferred operating range, with a constant pressure-boosting performance as a constraint. The results demonstrated that the efficiency improvement exceeded 2 % across the targeted operating range. Moreover, the MoP exhibited a strong predictive capability, even in multi-parameter scenarios with limited sample data. Further vortex dynamics analysis revealed that loading redistribution reduced the incidence angle, suppressed flow separation on the blade suction surface, and, under high-flow conditions, regulated the dominant vortex transport mechanisms governed by vortex diffusion and dissipation. This research demonstrated that optimizing blade loading serves as an effective passive flow control strategy for MSCPs, enabling significant improvements in energy conservation.},
keywords = {Approximate model, CFD simulation, Energy efficiency enhancement, Flow diagnosis, Inverse Design, Multistage Centrifugal Pump},
pubstate = {published},
tppubtype = {article}
}
Multistage centrifugal pumps (MSCPs) are critical for high-pressure fluid transport, and their hydraulic efficiency directly affects the energy consumption of energy systems. However, flow instabilities result in substantial energy loss. This study employed blade loading theory, which is closely related to the flow field state, to achieve a parametric blade design. A non-expert-driven optimization framework was constructed by integrating the Metamodel of Optimal Prognosis (MoP) with the technique for order of preference by similarity to the ideal solution based on the entropy weight method (EW-TOPSIS). The optimization objective was to improve the hydraulic efficiency of the pump in the preferred operating range, with a constant pressure-boosting performance as a constraint. The results demonstrated that the efficiency improvement exceeded 2 % across the targeted operating range. Moreover, the MoP exhibited a strong predictive capability, even in multi-parameter scenarios with limited sample data. Further vortex dynamics analysis revealed that loading redistribution reduced the incidence angle, suppressed flow separation on the blade suction surface, and, under high-flow conditions, regulated the dominant vortex transport mechanisms governed by vortex diffusion and dissipation. This research demonstrated that optimizing blade loading serves as an effective passive flow control strategy for MSCPs, enabling significant improvements in energy conservation.
