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Investigation on the vortical structures by the Liutex method in turbulent channels at Reτ = 180 with scalloped and triangular riblet control J. Hydrodyn. (IF 2.5) Pub Date : 2024-03-21
Abstract Riblets are a series of small protrusions formed along the flow direction, which have been extensively studied as a passive turbulent drag reduction technique. Experiments and numerical simulations have shown that well-designed riblets can significantly reduce drag in turbulent flows, making them highly promising and valuable for various applications. In this study, we focus on a scalloped
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Cavitation research with computational fluid dynamics: From Euler-Euler to Euler-Lagrange approach J. Hydrodyn. (IF 2.5) Pub Date : 2024-03-14
Abstract Unsteady cavitating flow often contains vapor structures with a wide range of different length scales, from micro-bubbles to large cavities, which issues a big challenge to precisely investigate its evolution mechanism by computational fluid dynamics (CFD) method. The present work reviews the development of simulation methods for cavitation, especially the emerging Euler-Lagrange approach
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Time-frequency analysis of internal waves generated by a towed and self-propelled submerged body model J. Hydrodyn. (IF 2.5) Pub Date : 2024-02-22 Yu-hang Li, Fei-yu Chen, Li-ping Qin, Ke Chen, Yun-xiang You
The spectrogram, based on a short-time Fourier transform, can visualize the time-dependent frequency spectrum of waves and is easy to compute. This time-frequency analysis method provides crucial information about waves generated by moving vessels and has been utilized to analyze Kelvin ship waves and internal waves. To further study the internal waves induced by a submerged body, an experiment is
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A fully nonlinear approach for efficient ship-wave simulation J. Hydrodyn. (IF 2.5) Pub Date : 2024-02-22 Kai-yuan Shi, Ren-chuan Zhu
This paper presents an efficient time-domain method for simulating nonlinear ship waves. The proposed method, implemented in an earth-fixed coordinate system, integrates a compact boundary element domain within a high-order spectral layer, enabling accurate modeling of both near-field and far-field ship waves. An overset mesh method and an attention mechanism are employed to track the moving ship.
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Experimental study on effects of air injection on cavitation pressure pulsation and vibration in a centrifugal pump with inducer J. Hydrodyn. (IF 2.5) Pub Date : 2024-02-05 Yan-hong Mao, Hou-lin Liu, Yong Wang, Jie Chen, Fei Liu
Cavitation commonly induces performance deterioration and system vibration in many engineering applications. This paper aims to investigate the effects of air injection on cavitation evolution, pressure pulsation and vibration in a centrifugal pump with inducer. In this paper, the high-speed camera is used to capture the gas flow pattern and cavitation evolution process in the inducer. The impacts
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Study of the influence of added water and contained water on structural vibrations and acoustic radiation using different dynamic modeling methods J. Hydrodyn. (IF 2.5) Pub Date : 2024-02-05 Li-bo Qi, Yue Yu, Huai-cheng Tang, Ming-song Zou
Using the 3-D sono-elasticity method and the simplified nonstructural mass method, the different dynamic modeling methods of the added water for a single-hull structure are first analyzed in this study. Then, the complete internal flow field method and the simplified nonstructural mass method of the contained water between the double hulls of a double-hull structure are investigated. Finally, based
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Numerical investigation on interaction between regular waves and a fully submerged horizontal cylinder J. Hydrodyn. (IF 2.5) Pub Date : 2024-02-01
Abstract This paper presents a 2-D numerical investigation on interaction between regular waves and a fully submerged horizontal cylinder. A mathematical model of numerical wave tank with two-way fluid-solid interactions were developed and validated. The wave-induced vibrations of a single-degree-of-freedom cylinder were simulated at eleven gap ratios (d / a = 8, 10, 12, 14, 16, 18, 20, 22, 24, 28
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Correlation analysis of cavitation-induced pressure pulsation and vibration in a bulb turbine J. Hydrodyn. (IF 2.5) Pub Date : 2024-02-01 Tian-shu Li, Jian-jun Feng, Guo-jun Zhu, Yun-zhe Li, Xing-qi Luo
Cavitation is one of the main causes of deteriorating stability of bulb turbines. To enhance their stability, this study examines the effects of runner cavitation on draft tube pressure fluctuation and vibration in bulb turbine through experimental methods. With varying cavitation coefficients, a synchronous test system, including a high-speed camera, vibration acceleration sensors and pressure pulsation
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Flow turbulence presented by different vegetation spacing sizes within a submerged vegetation patch J. Hydrodyn. (IF 2.5) Pub Date : 2024-02-01 Chukwuemeka Kingsley John, Jaan H. Pu, Yakun Guo, Prashanth R. Hanmaiahgari, Manish Pandey
This study presents results from a vegetation-induced flow experimental study which investigates 3-D turbulence structure profiles, including Reynolds stress, turbulence intensity and bursting analysis of open channel flow. Different vegetation densities have been built between the adjacent vegetations, and the flow measurements are taken using acoustic Doppler velocimeter (ADV) at the locations within
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Theoretical investigation on the cavitation bubble dynamics near three spherical particles based on Weiss theorem J. Hydrodyn. (IF 2.5) Pub Date : 2024-02-01 Yu-ning Zhang, Zhi-ling Ding, Jing-rong Hu, Xiao-xiao Zheng, Jia-xin Yu, Jin-sen Hu
To research the dynamics of the cavitation bubble under the interaction of particle clusters, the bubble morphological evolutionary characteristics near three equal-sized spherical particles are theoretically explored in the present study based on the Weiss theorem and the velocity potential superposition theory. The three particles are arranged symmetrically, and the fluid velocity field near the
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Godunov-type solutions for gas-liquid two-phase transient flows with gas release effects J. Hydrodyn. (IF 2.5) Pub Date : 2024-02-01 Yan-qing Lu, Ling Zhou, Tong-Chuan Che, Zi-jian Xue, Yun-jie Li, Yin-ying Hu
The gas-liquid two-phase homogenous flow has been extensively investigated without the effect of gas release. However, the dissolved gas will release when internal water pressure drops below saturation pressure during hydraulic transients. This results in inaccuracy or even invalidity of the existing model for homogenous flows, especially for the reproduction of two-phase mass transfer processes. To
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Experimental investigation of the flow characteristics of jet pumps for zero flow-ratio conditions J. Hydrodyn. (IF 2.5) Pub Date : 2024-01-24 Yun-zhi Liang, Jiong Wang, Zu-ti Zhang, Bin Ji, Huai-yu Cheng, Xin-ping Long
Experimental research was conducted on the performance curves and the cavity evolution for different flow and geometric parameters in jet pumps for zero flow ratio (ZFR) conditions. New pressure ratio, Pr, flow ratio, qr, were used in place of the conventional performance parameters h, q, to characterize the jet pump flow performance. A super cavitation cavity in the jet pump was observed to fill most
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Hydrodynamic characteristics and noise reduction mechanism of a wave leading hydrofoil placed in the wake of a cylinder J. Hydrodyn. (IF 2.5) Pub Date : 2024-01-11
Abstract We have investigated the hydrodynamic and acoustic performance of a hydrofoil with a wave leading edge that is being ingested in a cylindrical wake, to explore the interaction and noise reduction mechanism with the use of near flow field and far field noise decoupled prediction methods of large eddy simulation (LES) and Ffowcs Williams-Hawkings (FW-H). Our results indicate that the wave leading
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Air bubble breakup in shear water flows generated by a plug conduit: An experimental investigation J. Hydrodyn. (IF 2.5) Pub Date : 2024-01-11 Han Wu, Mao-lin Zhou, Wei-lin Xu, Wang-ru Wei, Jian-bo Li
In the context of a sudden contraction plug conduit, the near-wall area experiences a significant shearing effect of water flow, however, the extent to which this shearing effect occurs in bubble-water flow and the related variation mechanisms of air bubble size and number remain unclear. This study employs a model test method to investigate the diffusion process of bubble-water flow in a sudden contraction
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Numerical analysis of turbulent fluctuations around an axisymmetric body of revolution based on wall-modeled large eddy simulations J. Hydrodyn. (IF 2.5) Pub Date : 2024-01-11 Kang-jian He, Fu-chang Zhou, Wei-wen Zhao, Jian-hua Wang, De-cheng Wan
Wall-modeled large eddy simulation (WMLES) is used to investigate turbulent fluctuations around an axisymmetric body of revolution. This study focuses on evaluating the ability of WMLES to predict the fluctuating flow over the axisymmetric hull and analyzing the evolution of turbulent fluctuations around the body. The geometry is the DARPA SUBOFF bare model and the Reynolds number is 1.2×107, based
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An experimental study on the impact behavior of cavitation inside tip clearance of a hydrofoil J. Hydrodyn. (IF 2.5) Pub Date : 2024-01-11
Abstract Tip clearance cavitation is one of the most common cavitation phenomena exist on duct propellers, pumps and some hydraulic turbines, which may lead to erosion of the components. Due to the influence of the nearby wall, cavitation inside the tip clearance is more complicated than other cases without interaction. So far, the understanding about the impact mechanism of tip clearance cavitation
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Investigations of the dynamical behaviors of a millimeter-scale cavitation bubble near the rigid wall J. Hydrodyn. (IF 2.5) Pub Date : 2023-12-28 Dan Zi, Dong-qiao He, Zhi-feng Yao, Fu-jun Wang, Qiang Zhong, Pin Lyu
The collapse of the cavitation bubble near the rigid wall emits shock waves and creates micro-jet, causing cavitation damage and operation instability of the hydraulic machinery. In this paper, the millimeter-scale bubble near the rigid wall was investigated experimentally and numerically with the help of a laser photogrammetry system with nanosecond-micron space-time resolution and the open source
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Entropy production by dissipation effects and characteristic vortex evolution in a rocket turbopump J. Hydrodyn. (IF 2.5) Pub Date : 2023-12-12 De-you Li, Jia-qi Zhu, Rui-yi Zhang, Yi Zhang, Zhi-peng Li, Hong-jie Wang, Zhi-peng Ren
The relationship between entropy production and vortex evolution affects the efficiency and stability of rotating machinery. This study investigated the energy characteristics of a rocket turbopump and revealed the correlated mechanisms of the entropy production rate using the dissipation effects and characteristic vortex evolution. For the first time, direct and turbulent dissipation and rigid and
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Recent progress on the jetting of single deformed cavitation bubbles near boundaries J. Hydrodyn. (IF 2.5) Pub Date : 2023-12-12 Jing-zhu Wang, Guang-hang Wang, Qing-yun Zeng, Yi-wei Wang
Cavitation occurs widely in nature and engineering and is a complex problem with multiscale features in both time and space due to its associating violent oscillations. To understand the important but complicated phenomena and fluid mechanics behind cavitation, a great deal of effort has been invested in investigating the collapse of a single bubble near different boundaries. This review aims to cover
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A numerical study of hydrodynamic characteristics and hydrological processes in the coastal wetlands during extreme events J. Hydrodyn. (IF 2.5) Pub Date : 2023-12-12 Ming-liang Zhang, Xiao-sen Zhu, Yu-jia Wang, Heng-zhi Jiang, Lei Cui
Providing accurate predictions of extreme water levels through numerical simulation has become essential for disaster prevention and damage mitigation in coastal wetland areas. This study applies the FVCOM model to simulate storm surges caused by several typhoons in the Bohai Sea and the North Huanghai Sea. The vegetation drag force caused by salt marsh plants is inserted into the FVCOM model for model
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Induced noise of impeller stuck and passive rotation state in multi-stage pump without power drive under natural flow conditions J. Hydrodyn. (IF 2.5) Pub Date : 2023-11-30 Run-ze Zhou, Hou-lin Liu, Ru-nan Hua, Liang Dong, Kim Tiow Ooi, Cui Dai, Si-yuan Hu
The natural flow cooling strategy is commonly employed in modern high-speed vessels and nuclear-powered submarines. These vessels rely on the energy generated by their own speed to drive the cooling system and supply cooling water to the condenser. The circulating pump, which operates without a motor drive under natural flow conditions, is a large resistance component in the cooling system. However
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Numerical study on the aerodynamic and hydrodynamic performances of an ultra-high-speed AAMV J. Hydrodyn. (IF 2.5) Pub Date : 2023-11-30 Qi-jun Ni, Shi-jun Ji, Yi Jiang, Sheng-zhong Li, Yang Liu, Wei-tong Xu
In order to investigate the resistance performance of an ultra-high-speed aerodynamically alleviated marine vehicle (AAMV), finite volume method (FVM)-based computational fluid dynamics (CFD) software STAR CCM+ is used to simulate the forward motion of this vehicle. The calculated results are validated as they reach good agreement with experimental data. Comparing the motions of models with and without
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Experimental study of the dynamics of a single cavitation bubble excited by a focused laser near the boundary of a rigid wall J. Hydrodyn. (IF 2.5) Pub Date : 2023-11-30 Xiang-qing Zhang, Xiao-fei Zhang, Xu Qiu, Dan Gao, Yu-ning Zhang
Based on high-speed photographic experiments, this study presents a detailed qualitative and quantitative analysis of the dynamics of a single cavitation bubble near the boundary of a rigid wall in asymmetric settings. The main findings are reported as follows: (1) The non-sphericity of the bubble interface decreases with increasing spacing between the bubble and the boundary, and the asymmetry of
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Research on the collapse process of a near-wall bubble J. Hydrodyn. (IF 2.5) Pub Date : 2023-11-23 Bing Zhu, Wang Han, Wen-jun Xu, Wei Zhang
The effect of wall on the bubble collapse is significant. A compressible numerical simulation method based on the state equation was used to numerically calculate the collapse process of bubbles at different leaving wall distances. The results show that when the dimensionless distance between the bubble center and the wall is greater than zero, the bubble generates a high-pressure region at the top
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Numerical study on the wave pattern characteristic of air layer in cavity and the effects of multiple influence factors J. Hydrodyn. (IF 2.5) Pub Date : 2023-11-23 Xiao-song Zhang, Xue-qin Ji, Lei-qiang Chen, Li-jin Gao, Hong-bo Huang, Fang-wen Hong
Air-layer drag reduction (ALDR) technology for ship energy saving is getting more and more attention in recent years because of the outstanding drag reduction effect. In order to promote practical application, it is necessary to fully understand the two phase flow characteristics of the air layer. Recent experimental studies have shown that the surface of the air layer presents wave pattern, which
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Influence of bubble-particle distance on the dynamic behaviors of a cavitation bubble near a particle J. Hydrodyn. (IF 2.5) Pub Date : 2023-11-16 Yun Dai, Hui Zhang, Ting Chen
Cavitation and silt-erosion often co-exist, causing severe damage on fluid machinery. In this paper, the dynamic behavior of a cavitation bubble near a fixed spherical particle is numerically studied, with the focus on the influence of the stand-off distance γ on the bubble collapse morphology, micro-jet velocities and pressure on the particle. With the increase in the value of γ, the bubble profile
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Effect of liquid viscoelasticity on the interactions between cavitation bubbles and free surfaces J. Hydrodyn. (IF 2.5) Pub Date : 2023-11-16 Yang Liu, Zhi-ying Zheng, Zhi-bo He, Tian-bao Zeng, David Ezekoye, Wei-hua Cai, Hong Qi
The influence of liquid viscoelasticity on the interaction between cavitation bubbles and free surfaces is of great practical significance in understanding bubble dynamics in biological systems. A series of millimeter cavitation bubbles were induced by laser near the free surfaces of the water and viscoelastic polyacrylamide (PAM) solutions with different concentrations. The effects of liquid viscoelasticity
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CFD simulations targeting the performance of the NTNU BT1 wind turbine using overset grids J. Hydrodyn. (IF 2.5) Pub Date : 2023-11-16 Mao-kun Ye, Ni-na Wang, Hamn-Ching Chen, De-cheng Wan
In the present study, the performance of the NTNU Blind Test 1 wind turbine is analyzed in the computational fluid dynamics (CFD) simulations by using the CFD code FANS with structured overset grids. First, the numerical methods including the governing equations, the turbulence closure model, and the flow solver are introduced. In addition, the NTNU BT1 wind tunnel experiment is described. Then, structured
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Investigation of cavitation erosion caused by laser-induced single bubble collapse near alloy coating surface J. Hydrodyn. (IF 2.5) Pub Date : 2023-11-09 Hai-gang Wen, Zhi-feng Yao, Qin Wu, Yu-rong Sun, Chen-xi Yang, Qiang Zhong
To investigate the mechanism of cavitation erosion caused by laser-induced single bubble near the surface coating alloy coating material, we utilized a nanosecond resolution photography system based on a Q-switched Nd: YAG laser and conventional industrial camera to carefully observe the transient process of bubble collapse under different conditions. We analyzed the generation of collapse microjets
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Identification of vortex boundaries in two-dimensional incompressible flows based on the Liutex-shear interaction J. Hydrodyn. (IF 2.5) Pub Date : 2023-11-02 Bi-yu Pang, Zhang-dan Yu, Bo-Wen Yan, Yi-qian Wang, Chaoqun Liu
According to the Liutex-shear decomposition, vorticity can be decomposed into a rotational part, i.e., the Liutex vector, and a residual shear part. With this decomposition, the vorticity transport equation can be used to formulate a governing equation for Liutex easily for two-dimensional incompressible flows with a source term depending on the residual shear. The dynamics of Liutex-identified structures
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Scaling laws for the intermittent swimming performance of a flexible plate at low Reynolds number J. Hydrodyn. (IF 2.5) Pub Date : 2023-10-20 Lin-lin Kang, Shi-xian Gong, Xi-Yun Lu, Wei-cheng Cui, Di-xia Fan
Many species of fish and birds travel in intermittent style, yet the combined influence of intermittency and other body kinematics on the hydrodynamics of a self-propelled swimmer is not fully understood. By formulating a reduced-order dynamical model for intermittent swimming, we uncover scaling laws that link the propulsive performance (cursing Reynolds number Rec, thrust T̄, input power P̄ and cost
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Numerical investigations of focused wave interact with a moving cylinder J. Hydrodyn. (IF 2.5) Pub Date : 2023-10-20 Yuan Zhuang, Fu-chang Zhou, Wen-jun Zhou, De-cheng Wan
This paper presents a numerical study on focused wave and current interactions with a cylinder. The cylinder is moving in the opposite direction to the wave propagation. An effective computational decomposition method is adopted to reduce the calculation resources. A potential solver high-order spectral (HOS) method is applied to generate focused wave field, while our in-house computational fluid dynamics
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Scale effects on bow wave breaking of KCS ship model: Insights from DDES investigations J. Hydrodyn. (IF 2.5) Pub Date : 2023-10-20 Jian-hua Wang, Wen-tao Wang, De-cheng Wan
Ship bow wave breaking is a common phenomenon during navigation, involving complex multi-scale flow interactions. However, the understanding of this intense free surface flow issue is not sufficiently deep, especially regarding the lack of research on the impact of scale effects on bow wave breaking. This paper focuses on the benchmark ship model KCS and conducts numerical simulations and comparative
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Numerical investigation of the cavitation noise around a marine propeller focusing on the influence of ventilation J. Hydrodyn. (IF 2.5) Pub Date : 2023-10-20 Shu-jian Lyu, Bin Ji, Xin-cheng Wang, Zhi-wen Zhan, Da-hai Zhang
Cavitation noise around propellers has many adverse effects. It is still very limited nowadays to inhibit propeller cavitation noise in engineering. In this study, the cavitation noise around a PPTC propeller is simulated using the large eddy simulation (LES) coupled with the porous Ffowcs Williams-Hawkings (PFW-H) equation. The investigation aims to find a strategy to suppress cavitation noise and
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Experimental research of the cavitation bubble dynamics during the second oscillation period near a spherical particle J. Hydrodyn. (IF 2.5) Pub Date : 2023-09-27 Xiao-yu Wang, Hong-chen Su, Shao-wei Li, Guan-hao Wu, Xiao-xiao Zheng, Ya-xin Duan, Yu-ning Zhang
In this paper, the dynamic behaviors of the cavitation bubble near a fixed spherical particle during the second oscillation period are analyzed based on the high-speed photographic system. The deformation and motion of the bubble during the second period are investigated by changing the distance between the particle and the bubble and the maximum radius of the bubble. Meanwhile, the variation of the
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Investigation on the dynamic behavior of cloud cavitation around a flexible hydrofoil J. Hydrodyn. (IF 2.5) Pub Date : 2023-09-27 Yun-qing Liu, Wei Zhao, Zhi Pan, Zhi-pu Guo, Rui Yuan, Qin Wu
The objective of this paper is to investigate the dynamic behavior of cloud cavitating flow around a flexible hydrofoil with experimental and numerical methods. The tightly coupled fluid-structure interaction (FSI) modeling is applied and validated with the experimental data. The Q - criterion and ω - criterion are applied to illustrate the interaction between the vortex structures and cavities. The
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Speculation of fluid dynamics equations based on Liutex theory and constitutive relation of symmetric shearing deformation J. Hydrodyn. (IF 2.5) Pub Date : 2023-09-27 Shuai-chen Zhu, Duo Wang, Yang Liu, Hongyi Xu
The fluid kinematics of Liutex decomposes a velocity gradient tensor (VGT) of ∇v into four components, including rotation (R), stretching/compressing (SC), anti-symmetric shear (Santi-sym) and symmetric shear (Ssym), as oppose to the traditional Cauchy-Stokes decomposition where a VGT was decomposed into the strain rate and vorticity tensors. The current study limpidly clarified the physical meanings
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Laser-induced cavitation bubble near boundaries J. Hydrodyn. (IF 2.5) Pub Date : 2023-10-01
Abstract Laser-induced cavitation bubble has been widely used to investigate the mechanisms of hydraulic machinery cavitation erosion and to explore applications in atomization, alloy strengthening, ultrasonic chemistry, biomedicine, surface cleaning and materials processing. This paper consolidates existing research findings on the cavitation bubble dynamics near different boundaries and provides
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Numerical investigations on performance improvement mechanism of a high-power vertical centrifugal pump with special emphasis on hydraulic component matching J. Hydrodyn. (IF 2.5) Pub Date : 2023-09-21 Gang Yang, Xi Shen, De-sheng Zhang, Wen-hua Luo, Jia Meng, Xu-tao Zhao
The purpose of this paper is to investigate the performance improvement mechanism of a high power vertical centrifugal pump by using numerical calculations. Therefore, a comparative study of energy losses and internal flow characteristics in the original and optimized models was carried out with special attention to the hydraulic component matching. The optimized model (model B) was obtained by optimizing
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Large-eddy simulation of turbulent boundary layer flow over multiple hills J. Hydrodyn. (IF 2.5) Pub Date : 2023-09-21 Ying Deng, Kai Leong Chong, Yan Li, Zhi-ming Lu, Bo-fu Wang
Atmospheric boundary layer (ABL) flow over multiple-hill terrain is studied numerically. The spectral vanishing viscosity (SVV) method is employed for implicit large eddy simulation (ILES). ABL flow over one hill, double hills, and three hills are presented in detail. The instantaneous three-dimensional vortex structures, mean velocity, and turbulence intensity in mainstream and vertical directions
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Lattice Boltzmann modeling of backward-facing step flow controlled by a synthetic jet J. Hydrodyn. (IF 2.5) Pub Date : 2023-09-21 Tian-yang Lu, Hai-bao Hu, Jian Song, Fan Zhang, Heng Zhang, Zhen-lin Xie, Feng Ren
This article investigates the effect of a synthetic jet (SJ) on the flow over a backward-facing step (BFS) in the weakly turbulent flow regime using the lattice Boltzmann method. The SJ operates with various momentum coefficients Cμ and forcing frequencies f *jet . As Cμ increases, the reattachment length decreases, whereas increasing f *jet causes the reattachment length at first decrease and then
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Flow hydrodynamics drive effective fish attraction behaviour into slotted fishway entrances J. Hydrodyn. (IF 2.5) Pub Date : 2023-09-12 Maryam Farzadkhoo, Richard T. Kingsford, Iain M. Suthers, Stefan Felder
Effective fishways rely on attracting fish, utilising the natural rheotactic behaviour of fish to orient into an attraction flow near the entrance. Despite the critical importance of attraction, understanding of the hydrodynamics of vertical slot entrances in relation to fish behaviour remains poor. Herein, hydrodynamic measurements of flows at slotted fishway entrances were experimented with two different
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Retrofitting low-performance units to abate sewer overflow pollution based on mathematical model and Sobol algorithm J. Hydrodyn. (IF 2.5) Pub Date : 2023-09-12 Zhi-chao Zhao, Xiao-min Huang, Hai-long Yin, Jun-bo Wen, Xiao-wei Fu
Optimal retrofit of low-performance units (LPUs) is promising to abate overflow pollutant mass loading of sewer systems during wet-weathers. This study presents a combination of mathematical model and Sobol algorithm to help identify LPUs of sewer systems and design retrofitting strategies. Therefore, the solution to minimize the overflow pollutant mass loading from sewers systems can be efficiently
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Comparative study of reduced-order modeling method for the cavitating flow over a hydrofoil J. Hydrodyn. (IF 2.5) Pub Date : 2023-09-12 Yan-zhao Wu, Ran Tao, Di Zhu, Ruo-fu Xiao
As a high-dimensional complex nonlinear dynamic system, the analysis of the essence of flow has always been a difficult problem, especially in the flow including phase change. In recent years, it has become a feasible method to reduce the dimension of flow structure by reduced-order modeling (ROM) methods. In this paper, through the cavitation numerical simulation of NACA0015 hydrofoil, two ROM methods
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Advances on numerical and experimental investigation of ship roll damping J. Hydrodyn. (IF 2.5) Pub Date : 2023-08-15 Patrick Sumislawski, Moustafa Abdel-Maksoud
This paper presents recent developments towards efficient and reliable methods for roll damping estimation based on numerical simulations as well as model tests using the harmonic excited roll motion (HERM) technique. A newly designed automatic roll damping estimation procedure shows the advantage of a just-in-time post processing of experimental measurement results. Real-time analysis of the measured
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Double-plume Lagrangian particle tracking model and its application in deep water oil spill J. Hydrodyn. (IF 2.5) Pub Date : 2023-08-15 Xin-wei Ye, Xiao-jing Niu, Jian Jiang
Due to the density stratification of sea water, the dispersed oil droplets and gas bubbles with small diameters, as well as the dissolved components, may remain in some specific depths. The double-plume Lagrangian particle tracking model for bubbly plumes in vertical density stratified environments is improved and applied to predict the underwater pollutants in a blowout. This model considers the different
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Numerical study on roll dynamics of damaged ship in beam waves and calm water J. Hydrodyn. (IF 2.5) Pub Date : 2023-08-15 Zhi-yun Huang, Zhi-liang Gao, Sang-ming Xu
Computational fluid dynamics is used to study the roll dynamics of a damaged ship in beam waves with various steepnesses and in calm water. The wave-making method, which combines the velocity-inlet boundary and momentum source with the fifth-order Stokes theory, is employed for wave generation. The SST k-ω turbulence model with a modification to the turbulent viscosity in Reynolds stress is adopted
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LES investigation of the tip vortex cavitating flow with special emphasis on the interaction between cavitation and vorticity by a modified cavitation model J. Hydrodyn. (IF 2.5) Pub Date : 2023-08-15 Xin-ran Liu, Tao Wang, Xiao-yang Zhao, Tai-ran Chen
Cavitation within the tip vortex (TV) flow remains a challenging issue in the design of high-speed and low-noise hydraulic machinery. In this paper, the TV cavitating flow around an elliptical hydrofoil is calculated by using large eddy simulation (LES) combined with a modified Schnerr-Sauer (S-S) cavitation model. The original S-S cavitation model is modified by taking into account the typical effect
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The prediction of external flow field and hydrodynamic force with limited data using deep neural network J. Hydrodyn. (IF 2.5) Pub Date : 2023-08-15 Tong-sheng Wang, Guang Xi, Zhong-guo Sun, Zhu Huang
Predicting the external flow field with limited data or limited measurements has attracted long-time interests of researchers in many industrial applications. Physics informed neural network (PINN) provides a seamless framework for combining the measured data with the deep neural network, making the neural network capable of executing certain physical constraints. Unlike the data-driven model to learn
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Application of IITM-RANS3D to free-fall water entry of prismatic and non-prismatic finite wedges J. Hydrodyn. (IF 2.5) Pub Date : 2023-08-15 Shaswat Saincher, Kshitij Srivastava, R. Vijayakumar, V. Sriram
High-speed watercraft and ships undergo coupled motions which make the front portion of the hull exit and violently re-enter water. This induces short-term slamming loads that may compromise the structural integrity of the hull. The slamming of the bow can be modeled as straight wedges of different deadrise angles (DRAs) falling into water from different heights. The advent of computational fluid dynamics
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Assessment of subgrid-scale models in wall-modeled large-eddy simulations of turbulent channel flows J. Hydrodyn. (IF 2.5) Pub Date : 2023-07-27 Wei-wen Zhao, Fu-chang Zhou, Guo-qing Fan, De-cheng Wan
Considering the demanding of grid requirements for high-Reynolds-number wall-bounded flow, the wall-modeled large-eddy simulation (WMLES) is an attractive method to deal with near wall turbulence. However, the effect of subgrid-scale (SGS) models for wall-bounded turbulent flow in combination with wall stress models is still unclear. In this paper, turbulent channel flow at Reτ =1 000 are numerically
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Numerical analysis of the performance of a three-bladed vertical-axis turbine with active pitch control using a coupled unsteady Reynolds-averaged Navier-Stokes and actuator line model J. Hydrodyn. (IF 2.5) Pub Date : 2023-07-20 Rui-wen Zhao, Angus C. W. Creech, Ye Li, Vengatesan Venugopal, Alistair G. L. Borthwick
In this paper, we present a numerical model of a vertical-axis turbine (VAT) with active-pitch torque control. The model is based upon the Wind and Tidal Turbine Embedded Simulator (WATTES) and WATTES-V turbine realisations in conjunction with the actuator line method (ALM), and uses OpenFOAM to solve the unsteady Reynolds-averaged Navier-Stokes (URANS) equations with two-equation k - ε turbulence
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Global cavitation and hydrodynamic characteristics of a composite propeller in non-uniform wake J. Hydrodyn. (IF 2.5) Pub Date : 2023-07-20 Dan-dan Zhang, Lu-lu Dong, Qin Wu, Jing Zhang, Guo-yu Wang
The composite propeller has attracted much interest due to its excellent mechanical properties such as high specific stiffness and high specific strength, hence there is an increasing interest in utilizing the composite materials to improve the hydrodynamic and structural performance of marine propellers. The objective of this paper is to study the cavitation performance of composite propellers based
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Longitudinal dispersive coefficient in channels with aquatic vegetation: A review J. Hydrodyn. (IF 2.5) Pub Date : 2023-07-20 Liu Yang, Hao-ze Fang, Zhong-hua Yang, Wen-xin Huai
The determination of longitudinal dispersion coefficient in rivers is necessary for pollution control, environmental risk assessment, and management. In rivers with aquatic vegetation, the flow field is remarkably modified by canopies, which affects velocity profiles and dispersion characteristics dominated by the heterogeneity of the velocity field. The dispersion is deduced from lateral and vertical
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Optimization of closing law of turbine guide vanes based on improved artificial ecosystem algorithm J. Hydrodyn. (IF 2.5) Pub Date : 2023-07-20 Li-ying Wang, Jia-jie Zhang, Hong-gang Fan
Optimization of the closing law of the guide vane is the most economical and efficient way to reduce the risk incurred by pressure and speed excursions, thus guaranteeing the security of the hydro-turbine and the whole hydraulic network. In order to optimize the closing law of the guide vane of hydraulic turbine, an improved artificial ecosystem optimization algorithm was proposed (IAEO). The reverse
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Hydrodynamic performances and wakes induced by a generic submarine operating near the free surface in continuously stratified fluid J. Hydrodyn. (IF 2.5) Pub Date : 2023-07-20 Liu-shuai Cao, Gang Gao, En-kai Guo, De-cheng Wan
The wake of a submarine is a crucial element that greatly affects its stealth and hydrodynamic performance. To investigate the propagation and evolution characteristics of submarine wakes in a stratified fluid, particularly under free surface conditions, a numerical method to simulate the linearly stratified environment was developed. A thermocline model based on Boussinesq assumption was introduced
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Evolution of vortex structure around a wall-mounted rough hemisphere J. Hydrodyn. (IF 2.5) Pub Date : 2023-07-06 Xiang Qiu, Hao-xuan Liu, Jia-hua Li, Yi-zhou Tao, Yu-lu Liu
In this paper, the large eddy simulation (LES) method is used to calculate Reynolds numbers the range in the range of 3 000–30 000 (based on the diameter of the hemisphere D), and then the statistical analysis method is used to study the influence of Re on the characteristics of the flow field around the rough hemisphere and the evolution law of the tail vortex. The effect of the Reynolds number on
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Effects of single circular synthetic jet on turbulent boundary layer J. Hydrodyn. (IF 2.5) Pub Date : 2023-07-06 Jin-hao Zhang, Biao-hui Li, Tian-hai Ping, Nan Jiang
The periodic synthetic jet emerging from a circular orifice actively controls the turbulent boundary layer (TBL). A time-resolved particle image velocimetry (TR-PIV) system was designed to capture the velocity field database and based on the single-pixel ensemble correlation (SPEC) algorithm, an average drag reduction rate of 6.2% was obtained. The results show that the synthetic jet causes a wide
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Research on bubble trajectory and flow structure in helical-axial multiphase pump J. Hydrodyn. (IF 2.5) Pub Date : 2023-07-06 Hui Quan, Chen-xi Sun, Kai Song, Ya-nan Li, Xiao-yi Liu, Xue-ling Yang, Liang Wang
The oil-gas two-phase hybrid transportation technology is one of the innovative technology directions for the exploitation and transportation of marginal and deep ocean oilfields. The helical-axial multiphase pump is a key equipment for oil and gas extraction. At this stage, most of the research on this kind of pump focuses on the improvement of the structure and conveying performance. However, because
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Numerical simulations of faraday waves in cylindrical and hexagonal tanks based on MPS method J. Hydrodyn. (IF 2.5) Pub Date : 2023-05-30 Cong-yi Huang, Wei-wen Zhao, De-cheng Wan
When a partially loaded liquid container vibrates along the vertical direction, the liquid inside will oscillate regularly, which is called Faraday wave. In some cases, the wave form of the Faraday wave is stable and smooth, and sometimes there is violent wave breaking and liquid splashing. In this paper, the Faraday waves inside the cylindrical tank and the hexagonal tanks are simulated by the in-house