Journal of Hydrodynamics最新文献_第3页

Study of multi-scale turbulence structures in lateral inlet/outlet of pumped storage power stations 抽水蓄能电站侧进/出口多尺度湍流结构研究

IF 4 3区工程技术

Journal of Hydrodynamics Pub Date : 2026-07-31 DOI: 10.1007/s42241-026-0052-7

Gang-gui Guo, Ya-kun Liu, Ze Cao, Di Zhang, Yang-yu Deng

{"title":"Study of multi-scale turbulence structures in lateral inlet/outlet of pumped storage power stations","authors":"Gang-gui Guo, Ya-kun Liu, Ze Cao, Di Zhang, Yang-yu Deng","doi":"10.1007/s42241-026-0052-7","DOIUrl":"10.1007/s42241-026-0052-7","url":null,"abstract":"<div><p>Under outflow conditions, water flows from the inlet/outlet to the reservoir, and the inlet/outlet experiences complex separated flow, which affects flow efficiency. In this study, proper orthogonal decomposition (POD) methods are used to identify the main characteristics of the multi-scale motions and reveal the impact of these flow structures on the separated flow within the inlet/outlet. Flow separation first appears at the upper right corner of the inlet/outlet, then extends to cover the top of the inlet/outlet, leading to reduced flow efficiency. Shear layers are present above and below the core flow, with significant fluctuating momentum exchange. The separated flow is dominated by large-scale motions, with two main features observed. On the one hand, there is a large-scale streak structure at a frequency of the Strouhal number, <i>Sr</i> = 0.044, causing the core flow to oscillate back and forth along the streamwise direction, accompanied by oscillations within the separation zone. On the other hand, large-scale streak structures at frequencies <i>Sr</i> = 0.116–0.335 induce lateral oscillations in the core flow, which manifest as up-down and left-right movements. Small-scale motions significantly influence the turbulence characteristics of the separated flow. Vortical structures exist above and below the core flow, where their growth, merging, and breakup result in high turbulence intensity, increasing the head loss in the inlet/outlet. Studying the complex separated flow within the inlet/outlet contributes to optimizing the design of inlet/outlet in pumped storage power stations.</p></div>","PeriodicalId":637,"journal":{"name":"Journal of Hydrodynamics","volume":"38 3","pages":"503 - 517"},"PeriodicalIF":4.0,"publicationDate":"2026-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148807249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Seakeeping analysis of small vessels using CFD-modified potential simulation 基于cfd修正势模拟的小型船舶耐波性分析

IF 4 3区工程技术

Journal of Hydrodynamics Pub Date : 2026-07-31 DOI: 10.1007/s42241-026-0058-1

Seol Nam, Jong-Chun Park, Hyeon Kyu Yoon, Jun-Bum Park, Momchil Terziev, Atilla Incecik

{"title":"Seakeeping analysis of small vessels using CFD-modified potential simulation","authors":"Seol Nam, Jong-Chun Park, Hyeon Kyu Yoon, Jun-Bum Park, Momchil Terziev, Atilla Incecik","doi":"10.1007/s42241-026-0058-1","DOIUrl":"10.1007/s42241-026-0058-1","url":null,"abstract":"<div><p>Small vessels are particularly vulnerable to marine accidents due to their limited stability and frequent reliance on empirical design practices. A significant challenge in the seakeeping analysis of small vessels stems from the use of estimated damping coefficients, which are seldom validated against high-fidelity data despite their critical influence on motion predictions. To address this limitation, a hybrid simulation procedure, referred to as CFD-modified potential (CMP), is proposed to enhance the accuracy of response amplitude operator (RAO) predictions. The CMP integrates traditional linear potential-flow solvers with CFD. For seakeeping performance analysis, the target sea area is selected and wave spectra corresponding to sea states SS2, SS3, and SS4 are calculated. In the first step, six-degree-of-freedom (6DOF) motion analyses were performed for three representative small vessels under multiple wave conditions. Next, CFD simulations focusing on roll and pitch motions at the peak response wave headings and frequencies were performed to quantify damping ratios, which were then fed back into the potential-flow solver to refine the RAO predictions. Comparison with conventional potential-based analyses demonstrated that the CMP significantly improves the correlation with experiments, particularly for roll motion. Furthermore, the inclusion of pitch damping, often neglected in small-vessel design, resulted in more realistic predictions of pitch amplitudes. Overall, the CMP approach provides a robust and practical tool for improving the reliability of seakeeping performance analyses, offering a viable solution to the limitations of traditional empirical methods and contributing to the development of safer and more accurate small vessel designs.</p></div>","PeriodicalId":637,"journal":{"name":"Journal of Hydrodynamics","volume":"38 3","pages":"453 - 470"},"PeriodicalIF":4.0,"publicationDate":"2026-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148807247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Direct numerical simulation study of vortex birth-death density in open-channel flows 明渠流动旋涡生死密度的直接数值模拟研究

IF 4 3区工程技术

Journal of Hydrodynamics Pub Date : 2026-07-31 DOI: 10.1007/s42241-026-0053-6

Chun-yang Hu, Yu-kai Zhang, Qiang Zhong, Zhi-feng Yao, Fu-jun Wang

{"title":"Direct numerical simulation study of vortex birth-death density in open-channel flows","authors":"Chun-yang Hu, Yu-kai Zhang, Qiang Zhong, Zhi-feng Yao, Fu-jun Wang","doi":"10.1007/s42241-026-0053-6","DOIUrl":"10.1007/s42241-026-0053-6","url":null,"abstract":"<div><p>In open-channel flows, a notably higher spanwise vortex density near the free surface compared to other wall-bounded turbulent flows has been observed, termed the additional vortex phenomenon. Two hypotheses explain this phenomenon: The free-surface accumulation hypothesis, suggesting slower vortex dissipation in open-channel flows leading to vortex accumulation in the outer region, and the free-surface generation hypothesis, proposing that free surface restrictions on vertical motions enhance vortex generation, increasing vortex density near the surface. To elucidate the dominant origin mechanism of the additional vortex phenomenon, this study conducts direct numerical simulation (DNS) of open-channel flows and closed-channel flows at a friction Reynolds number <i>Re</i><sub><i>τ</i></sub> = 500. Using the <i>λ</i><sub>ci</sub> - criterion, the spanwise, streamwise, and vertical vortex densities variations with distance from the wall are identified and quantified for both flows, and the presence of the additional vortex phenomenon near the free surface in the open-channel DNS data is confirmed again. Furthermore, the vortex birth-death density is defined to elucidate the dominant origin mechanism of the additional vortex phenomenon. Through the analysis of the vortex birth-death density profiles, the exact birth location of the additional vortices can be pinpointed. The result reveals significant positive values for spanwise and streamwise vortices near the wall and free surface in open-channel flow, indicating substantial vortex generation, while small negative values in the central region suggest vortex dissipation. The results of the vortex birth-death density analysis support the free-surface generation hypothesis for the additional vortex phenomenon in open-channel flows.</p></div>","PeriodicalId":637,"journal":{"name":"Journal of Hydrodynamics","volume":"38 3","pages":"369 - 381"},"PeriodicalIF":4.0,"publicationDate":"2026-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148807250","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Experimental study of lateral aeration diffusion in free-falling jets 自由落体射流中侧向曝气扩散的实验研究

IF 4 3区工程技术

Journal of Hydrodynamics Pub Date : 2026-07-31 DOI: 10.1007/s42241-026-0057-2

Jing Gong, Jun Deng, Wang-ru Wei, Chao Liu

{"title":"Experimental study of lateral aeration diffusion in free-falling jets","authors":"Jing Gong, Jun Deng, Wang-ru Wei, Chao Liu","doi":"10.1007/s42241-026-0057-2","DOIUrl":"10.1007/s42241-026-0057-2","url":null,"abstract":"<div><p>High-velocity jets entrain air as they fall through the atmosphere, enhancing energy dissipation and thus being commonly used in high dams. However, the detailed evolution of self-aeration along such free-falling jets–from non-aerated to fully aerated–remains poorly understood. This study presents systematic large-scale experiments on free-falling jets, using a phase-detection probe, to examine their lateral aeration diffusion under various initial water depths and velocities. The test results show that the streamwise evolution of air entrainment can be divided into three stages–undeveloped, developing, and fully developed–and that the aerated flow region extends with increasing initial Froude number. It was also found that the average sectional void fraction is governed primarily by the initial geometry, e.g. the initial water depth and the trajectory length, rather than by the initial velocity. Moreover, the jet break-up length exceeds eight times the initial water depth and increases with the Froude number following a power law. A turbulent diffusion coefficient is introduced to fit the complex void fraction distribution into a single metric, which is proportional to the initial water depth and velocity. Based on these insights, predictive equations for the void fraction distribution and the average sectional void fraction under various initial flow conditions are proposed. These findings advance the fundamental understanding of air-water two-phase flow in high-velocity jets.</p></div>","PeriodicalId":637,"journal":{"name":"Journal of Hydrodynamics","volume":"38 3","pages":"532 - 546"},"PeriodicalIF":4.0,"publicationDate":"2026-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148807246","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Study of cavitation evolution characteristics during salvo water-exit of vehicles 车辆齐射出水空化演化特征研究

IF 4 3区工程技术

Journal of Hydrodynamics Pub Date : 2026-07-20 DOI: 10.1007/s42241-026-0050-9

Jie-wen Lu, Yao Shi, Shan Gao, Deng-hui Qin

{"title":"Study of cavitation evolution characteristics during salvo water-exit of vehicles","authors":"Jie-wen Lu, Yao Shi, Shan Gao, Deng-hui Qin","doi":"10.1007/s42241-026-0050-9","DOIUrl":"10.1007/s42241-026-0050-9","url":null,"abstract":"<div><p>This study systematically investigates the cavitation dynamics during the salvo water-exit of vehicles through comprehensive experiments conducted on a specially designed test platform. The research focuses on the cavitation interference characteristics and compares the motion behaviors of single and dual vehicles under typical operating conditions. Several key findings are revealed: During the salvo water-exit process, distinct asymmetrical cavitation collapse patterns were observed between consecutive vehicles. Specifically, the first vehicle exhibited a shorter cavitation collapse duration and a higher peak lateral acceleration compared with the second vehicle. Axial velocity analysis showed that the first vehicle achieved a higher maximum velocity retention rate and enhanced velocity attenuation characteristics compared with the second vehicle. Furthermore, when compared with single-vehicle water-exit, the first vehicle’s shoulder cavity reached a stable state more rapidly, and cavity shedding occurred earlier. During salvo water-exit, the second vehicle experienced more pronounced cavity collapse, with cavity length and thickness being smaller than those of a single vehicle under identical conditions. Further analysis indicated that for both single- and dual-vehicle underwater launches, cavity development at the shoulder was more restricted in the radial direction than in the axial direction. Notably, the salvo water-exit interval significantly suppressed the lateral velocity and acceleration of the vehicles, advanced the timing of the maximum axial velocity, and increased the attenuation rate during the collapse phase. These results provide valuable insights into the complex interactions between vehicles during salvo water-exit and offer guidance for the design and optimization of underwater vehicle launch systems.</p></div>","PeriodicalId":637,"journal":{"name":"Journal of Hydrodynamics","volume":"38 3","pages":"481 - 487"},"PeriodicalIF":4.0,"publicationDate":"2026-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148807626","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The effect of end conditions on vortex-induced vibration of a circular cylinder at subcritical to critical Reynolds numbers 端部条件对亚临界至临界雷诺数下圆柱涡激振动的影响

IF 4 3区工程技术

Journal of Hydrodynamics Pub Date : 2026-07-20 DOI: 10.1007/s42241-026-0051-8

Hai-bo Xu, Jia-song Wang, Yi-gang Gong

{"title":"The effect of end conditions on vortex-induced vibration of a circular cylinder at subcritical to critical Reynolds numbers","authors":"Hai-bo Xu, Jia-song Wang, Yi-gang Gong","doi":"10.1007/s42241-026-0051-8","DOIUrl":"10.1007/s42241-026-0051-8","url":null,"abstract":"<div><p>This study investigated the effect of varying end conditions on vortex-induced vibration (VIV) of a vertically mounted circular cylinder at the subcritical to critical Reynolds number (<i>Re</i>) range (3.14×10<sup>4</sup>–2.51×10<sup>5</sup>). Three endplate configurations were tested: upper and lower endplates, upper endplates only, and no endplates. Results showed that end conditions have a minor impact on peak amplitude but significantly alter the vibration branches. Notably, the no endplates configuration exhibited two amplitude peaks, with endplate effects becoming more significant above a <i>Re</i> of 1.0×10<sup>5</sup>. The frequency ratio remained within the lock-in region for all high <i>Re</i> tests, and with no endplates, the ratio stayed closer to unity. The effect of end conditions on hydrodynamic forces mirrored the amplitude response: Peak drag and lift forces were similar across all configurations. However, with no endplates, drag force remained substantially higher than the other conditions within a reduced velocity range of 6–8, and the lift force showed two peak values. Phase difference analysis revealed two phase jumps for both the only upper and no endplates configurations, corresponding to an expanded upper branch. These observed differences in amplitude and hydrodynamic forces were interpreted based on instantaneous pressure distributions.</p></div>","PeriodicalId":637,"journal":{"name":"Journal of Hydrodynamics","volume":"38 3","pages":"382 - 395"},"PeriodicalIF":4.0,"publicationDate":"2026-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148807625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Nonlinear evolution of focused wave groups on an uneven seafloor 不均匀海底聚焦波群的非线性演化

IF 4 3区工程技术

Journal of Hydrodynamics Pub Date : 2026-07-08 DOI: 10.1007/s42241-026-0048-3

Qian Wu, Xing-ya Feng, You Dong, Jun-nan Cui, De-zhi Ning

引用次数: 0

Two-phase flow simulations of dam-break problem by lattice Boltzmann method 用晶格玻尔兹曼方法模拟溃坝问题的两相流

IF 4 3区工程技术

Journal of Hydrodynamics Pub Date : 2026-07-02 DOI: 10.1007/s42241-026-0047-4

Seiya Watanabe, Changhong Hu

{"title":"Two-phase flow simulations of dam-break problem by lattice Boltzmann method","authors":"Seiya Watanabe, Changhong Hu","doi":"10.1007/s42241-026-0047-4","DOIUrl":"10.1007/s42241-026-0047-4","url":null,"abstract":"<div><p>To apply the lattice Boltzmann method (LBM) to violent free-surface flows in ocean engineering, rigorous validation of both numerical stability and accuracy is essential. This study quantitatively assessed the accuracy of a velocity-based two-phase LBM for gas-liquid flow simulations, with particular emphasis on wave impact pressures. Two dam-break benchmark problems–A simple dam-break and a dam-break involving a rectangular obstacle-were simulated, and the resulting pressure-time histories were compared with experimental data from previous studies. For coarse meshes, instantaneous peak pressures were generally underestimated relative to experimental measurements. As mesh resolution increased, the predicted peak pressures rose and approached the experimental values, although some sensors exhibited slight overestimation. The results demonstrate sufficient numerical stability for laboratory-scale dam-break simulations, with no nonphysical oscillations observed in the velocity field. The in-house LBM code was implemented on multi–GPU systems and enabled large-scale gas-liquid two-phase simulations with meshes up to 1932×600×600, corresponding to approximately 696 million lattice points. These findings highlight the potential of the LBM as a robust and scalable tool for high-resolution, massively parallel simulation of complex multiphase flows in ocean engineering.</p></div>","PeriodicalId":637,"journal":{"name":"Journal of Hydrodynamics","volume":"38 3","pages":"441 - 452"},"PeriodicalIF":4.0,"publicationDate":"2026-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148807393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Numerical evaluation of sediment erosion characteristics of the Pelton turbine injector 水轮机喷油器冲沙特性的数值评价

IF 4 3区工程技术

Journal of Hydrodynamics Pub Date : 2026-07-01 DOI: 10.1007/s42241-026-0046-5

Wen-rui Fan, Long-gang Sun, Heng-te Zhou, Zhao-ning Wang, Peng-cheng Guo

{"title":"Numerical evaluation of sediment erosion characteristics of the Pelton turbine injector","authors":"Wen-rui Fan, Long-gang Sun, Heng-te Zhou, Zhao-ning Wang, Peng-cheng Guo","doi":"10.1007/s42241-026-0046-5","DOIUrl":"10.1007/s42241-026-0046-5","url":null,"abstract":"<div><p>The injector plays a critical role in energy conversion in Pelton turbines, but intense sediment erosion can lead to local deformation and endanger turbine stability. This study uses a volume of fluid-Lagrange (VOF-Lagrange) multiphase flow model to simulate injector erosion, analyzing the impact of particle parameters and needle opening on wall abrasion morphology and predicting erosion loss. Results show that particle diameter has the greatest influence on sediment discharge and component erosion, followed by sediment concentration and needle opening. Vortex positions and particle diameter significantly affect wall erosion distribution. Erosion is most severe at the nozzle contraction, inner rib trailing edges, and needle tip, with the needle’s relative erosion ratio sensitive to particle diameter, concentration, and opening changes. Larger particles increase slip velocity and wall residence time, shifting erosion from banding to sheet and intensifying asymmetry. This study offers insights into injector erosion, providing a foundation for injector optimization in Pelton turbines.</p></div>","PeriodicalId":637,"journal":{"name":"Journal of Hydrodynamics","volume":"38 3","pages":"396 - 414"},"PeriodicalIF":4.0,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148807300","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Numerical investigation of generic submarine self-propulsion in free-surface waves with an autopilot controller 基于自动驾驶仪控制器的通用潜艇自由面波自推进数值研究

IF 4 3区工程技术

Journal of Hydrodynamics Pub Date : 2026-06-16 DOI: 10.1007/s42241-026-0045-6

Yu-heng Sun, Jie Zhu, Liu-shuai Cao, De-cheng Wan

{"title":"Numerical investigation of generic submarine self-propulsion in free-surface waves with an autopilot controller","authors":"Yu-heng Sun, Jie Zhu, Liu-shuai Cao, De-cheng Wan","doi":"10.1007/s42241-026-0045-6","DOIUrl":"10.1007/s42241-026-0045-6","url":null,"abstract":"<div><p>This study employs computational fluid dynamics (CFD) to investigate the attitude-keeping self-propulsion of a generic submarine in free-surface and wave environments under autopilot control. The Joubert BB2 hull form and Marine 7371R propeller are adopted as the reference models. Turbulent flow is resolved by solving the incompressible Reynolds averaged Navier-Stokes (RANS) equations in combination with the shear stress transport (SST) <i>k</i>-<i>ω</i> turbulence model, while free-surface dynamics are captured using the volume of fluid (VOF) method. To ensure numerical reliability, mesh-convergence studies are carried out with four levels of mesh resolution. An overset mesh technique is applied to the submarine hull and X-rudders, whereas a sliding mesh is used to represent propeller rotation. The autopilot is implemented as a proportional-derivative (PD) controller that adjusts attitude variables to maintain attitude-keeping self-propulsion. The influence of submergence depth and wave conditions on hydrodynamic characteristics is systematically examined: The presence of the free surface significantly alters the hydrodynamic loads, surface pressure distribution, and associated wave patterns during the self-propulsion process. Meanwhile, the wave action induces significant variations in the pitch angle, leading to distinct periodic oscillations in the submarine’s attitude.</p></div>","PeriodicalId":637,"journal":{"name":"Journal of Hydrodynamics","volume":"38 3","pages":"547 - 559"},"PeriodicalIF":4.0,"publicationDate":"2026-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148807451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0