European Journal of Mechanics B-fluids最新文献_第4页

A unidirectional phase-resolved wave prediction model based on deep Koopman embeddings 基于深库普曼嵌入的单向相位分辨波预测模型

IF 2.5 3区工程技术

European Journal of Mechanics B-fluids Pub Date : 2026-05-01 Epub Date: 2025-12-12 DOI: 10.1016/j.euromechflu.2025.204429

Zhongying Feng , Ye Wang , Chenghao Fu , Ruipeng Li , Kun Zheng , Zhan Wang

{"title":"A unidirectional phase-resolved wave prediction model based on deep Koopman embeddings","authors":"Zhongying Feng , Ye Wang , Chenghao Fu , Ruipeng Li , Kun Zheng , Zhan Wang","doi":"10.1016/j.euromechflu.2025.204429","DOIUrl":"10.1016/j.euromechflu.2025.204429","url":null,"abstract":"<div><div>The phase-resolved wave prediction is of vital importance for improving the safety and operations of structures in ocean engineering, such as floating wind turbines and wave energy converters. However, it is challenging for traditional physical methods to predict wave elevation accurately and efficiently in high sea states where the nonlinearity plays an important role. Inspired by the capability of the Koopman theory in solving nonlinear problems, a phase-resolved wave prediction model by combining deep learning with Koopman operator, referred to as DKWP, is designed. The high-order spectral method is employed for providing training and test data. To illustrate the effectiveness of the proposed method, we compare it with another four phase-resolved wave prediction models, including the models based on artificial neural network, long short-term memory, U-Net and linear wave theory. The models are trained under the sea states 3–5 with wide ranges of significant height, peak period and peak factor. Comparisons between the predicted wave elevation and true wave elevation indicate that DKWP outperforms the other models in terms of accuracy. The generalization of the DKWP is validated when it predicts the wave elevation under the sea states 6–7. In addition, to improve the interpretability of the DKWP, the eigenvalues of the Koopman operator in the proposed model are further analyzed.</div></div>","PeriodicalId":11985,"journal":{"name":"European Journal of Mechanics B-fluids","volume":"117 ","pages":"Article 204429"},"PeriodicalIF":2.5,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145837009","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

Threshold of thermoconvective flows in a liquid metal battery with thermal coupling with its environment 液态金属电池与环境热耦合时的热对流阈值

IF 2.5 3区工程技术

European Journal of Mechanics B-fluids Pub Date : 2026-05-01 Epub Date: 2025-12-22 DOI: 10.1016/j.euromechflu.2025.204446

Anupam M. Hiremath , Harunori N. Yoshikawa , Innocent Mutabazi

{"title":"Threshold of thermoconvective flows in a liquid metal battery with thermal coupling with its environment","authors":"Anupam M. Hiremath , Harunori N. Yoshikawa , Innocent Mutabazi","doi":"10.1016/j.euromechflu.2025.204446","DOIUrl":"10.1016/j.euromechflu.2025.204446","url":null,"abstract":"<div><div>Liquid Metal Battery (LMB) is a recent technology proposed to store the energy produced by intermittent sources such as solar cells, wind turbines or tidal power plants. The liquid metal batteries operate with large current densities but with very low open circuit voltages (OCV). A LMB consists of superimposed three layers of immiscible liquids in a stable stratification: the top layer made of light liquid metal and the bottom one made of dense liquid metal alloy sandwich the electrolyte layer (often a molten salt). Each layer has its own specific fluid properties and due to large difference in thermal and electrical conductivities between the liquid metals and the electrolyte, the application of a large current density can generate thermoconvective instabilities. The present works presents, in the framework of the linear stability analysis, the effects of the physical properties and thicknesses of liquid layers on the critical parameters on thermoconvective flows induced by Joule heating in a LMB of rectangular cross-section. The thermal coupling of the LMB with its environment described by the mixed thermal boundary conditions through the Biot number modifies the temperature profiles of the conduction state and reduces the threshold of all thermoconvective flows.</div></div>","PeriodicalId":11985,"journal":{"name":"European Journal of Mechanics B-fluids","volume":"117 ","pages":"Article 204446"},"PeriodicalIF":2.5,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145921070","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

CFD-guided design and performance evaluation of a mobile aerator for delaying channel ice formation cfd导向的移动缓冰器设计与性能评价

IF 2.5 3区工程技术

European Journal of Mechanics B-fluids Pub Date : 2026-05-01 Epub Date: 2025-11-30 DOI: 10.1016/j.euromechflu.2025.204428

Fangpeng Zhao , Zhihong Li , Yang Chen , Wei Cui

{"title":"CFD-guided design and performance evaluation of a mobile aerator for delaying channel ice formation","authors":"Fangpeng Zhao , Zhihong Li , Yang Chen , Wei Cui","doi":"10.1016/j.euromechflu.2025.204428","DOIUrl":"10.1016/j.euromechflu.2025.204428","url":null,"abstract":"<div><div>Addressing the ice formation issue in open-channel water conveyance during winter in cold regions, this study guided the design of a mobile device integrating both propulsion and aeration functions. By enhancing water surface flow velocity and temperature distribution, the developed apparatus effectively delays the ice formation process and extends the normal water conveyance period. In this study, the CFD approach was conducted to investigate the hydrodynamic and thermal performance of the mobile aeration device in an open channel environment. The overset mesh method was applied to simulate the rotational motion of aeration components, while the Eulerian mixture model was used to capture the changes in the channel’s physical fields, including velocity and temperature distribution. Simulation results demonstrated that the device significantly improves flow characteristics and temperature distribution in the surface layer of open channels. Through systematic parametric analysis, the optimal combination scheme of key operational parameters (travel speed and longitudinal spacing) was determined, achieving enhanced flow velocity and temperature rise effects over extensive water areas.</div></div>","PeriodicalId":11985,"journal":{"name":"European Journal of Mechanics B-fluids","volume":"117 ","pages":"Article 204428"},"PeriodicalIF":2.5,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145617637","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

Analysis of compliant tube properties and operating conditions in a Liebau pump 利宝泵柔性管特性及运行条件分析

IF 2.5 3区工程技术

European Journal of Mechanics B-fluids Pub Date : 2026-05-01 Epub Date: 2025-12-26 DOI: 10.1016/j.euromechflu.2025.204450

Manuel Rubio , Francisco Castro-Ruiz , José Sierra-Pallares , César Barrios-Collado , Joaquín Anatol

{"title":"Analysis of compliant tube properties and operating conditions in a Liebau pump","authors":"Manuel Rubio , Francisco Castro-Ruiz , José Sierra-Pallares , César Barrios-Collado , Joaquín Anatol","doi":"10.1016/j.euromechflu.2025.204450","DOIUrl":"10.1016/j.euromechflu.2025.204450","url":null,"abstract":"<div><div>This study examines asymmetric pumping in Liebau pumps, a type of valveless pump that generates unidirectional flow through the periodic compression of a flexible (compliant) tube. This pumping has applications in biomedical devices, microfluidics, and organ support. We investigate how the properties of the compliant tube and the operating conditions affect the pump performance, using dimensionless parameters. Experiments were performed with different configurations, varying the tube material (latex and rubber) and the fluid (water and water–glycerine mixture). The results indicate that the flow rate and resonant period depend on the stiffness of the tube and the viscous effects. It was observed that for small values of the Womersley number (<span><math><msup><mrow><mi>W</mi><mi>o</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span>), viscous effects significantly reduce the flow rate. In contrast, for large Womersley values, the semiempirical models previously proposed adequately predict the experimental behaviour. Effects such as the compliant tube depression, which were not accounted for in previous models, were also found to influence performance. This work extends the analysis of this type of pump to unexplored conditions, with the aim of expanding knowledge and enabling the use of Liebau pumps in real-world applications.</div></div>","PeriodicalId":11985,"journal":{"name":"European Journal of Mechanics B-fluids","volume":"117 ","pages":"Article 204450"},"PeriodicalIF":2.5,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145837005","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

Aerodynamic and aeroacoustic evaluation of slat and slot separation control on a small-scale HAWT: A computational study 小型HAWT狭缝分离控制的气动与气动声学评价：计算研究

IF 2.5 3区工程技术

European Journal of Mechanics B-fluids Pub Date : 2026-05-01 Epub Date: 2025-12-09 DOI: 10.1016/j.euromechflu.2025.204443

Sami Bouterra , Riyadh Belamadi , Abdelouaheb Djemili , Adrian Ilinca

{"title":"Aerodynamic and aeroacoustic evaluation of slat and slot separation control on a small-scale HAWT: A computational study","authors":"Sami Bouterra , Riyadh Belamadi , Abdelouaheb Djemili , Adrian Ilinca","doi":"10.1016/j.euromechflu.2025.204443","DOIUrl":"10.1016/j.euromechflu.2025.204443","url":null,"abstract":"<div><div>The global push toward clean energy has intensified the search for efficient, innovative technologies to harness renewable resources. Small-scale horizontal-axis wind turbines (HAWTs) offer a promising solution to meet growing urban energy demands with minimal environmental impact. This computational study investigates the aerodynamic and aeroacoustic effects of two passive flow separation control techniques, slat and slot, applied to the blades of a small-scale HAWT. Using the NREL S809 Phase II rotor as a benchmark, simulations are conducted using the steady Moving Reference Frame (MRF) and the unsteady Sliding Mesh Motion (SMM) approaches. The k-ω SST turbulence model is validated against experimental data for multiple inflow conditions. The results demonstrate that flow separation is significantly mitigated by both control methods, particularly at higher wind speeds and at specific locations along the blade span. Quantitatively, the slat and slot configurations yield power output increases of 8.74 % and 21.07 %, respectively, compared to the baseline case. However, aeroacoustic analysis reveals that the slot introduces a sound pressure level (SPL) increase of up to 20 dB near 1 kHz, while providing a more balanced performance in terms of noise and energy gain. These findings highlight the slot configuration as a particularly effective solution for enhancing aerodynamic efficiency, while the slat provides a more balanced aeroacoustic profile. The choice between them involves a trade-off between maximum power gain and noise-control requirements in small-scale wind energy systems.</div></div>","PeriodicalId":11985,"journal":{"name":"European Journal of Mechanics B-fluids","volume":"117 ","pages":"Article 204443"},"PeriodicalIF":2.5,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145734409","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

An analytical model for whirlwinds of finite width rising with bounded velocity and decaying outflow: Application to dust devils 有限宽度有界上升速度和衰减出口漩涡的解析模型：在尘卷风中的应用

IF 2.5 3区工程技术

European Journal of Mechanics B-fluids Pub Date : 2026-05-01 Epub Date: 2025-12-27 DOI: 10.1016/j.euromechflu.2025.204451

Sanjay Kumar Pandey, Kriti Yadav

{"title":"An analytical model for whirlwinds of finite width rising with bounded velocity and decaying outflow: Application to dust devils","authors":"Sanjay Kumar Pandey, Kriti Yadav","doi":"10.1016/j.euromechflu.2025.204451","DOIUrl":"10.1016/j.euromechflu.2025.204451","url":null,"abstract":"<div><div>This study presents an analytical model that extends previous formulations by incorporating axial dependence in all velocity components, thus offering a more realistic representation of dust devil dynamics. We address the limitations of the fundamental model of Vyas and Majdalani (2006), such as unbounded velocity and infinite vortex width, by modifying the stream function, which captures radial and axial variation of velocity. The velocity components are physically bounded and consistent with observed vortex structures. Additionally, the radial pressure distribution is derived, and the flow field is analysed using normalized radial, axial, and azimuthal velocities. The azimuthal velocity is computed from the radial and axial flows using the angular momentum equation. It increases from the centre, peaks near the periphery, and gradually decays to zero toward the axis. This model represents the compact features of dust devils by producing a smooth, confined structure with consistent vertical dependence, unlike alternative models that introduce abrupt transitions or unbounded behaviour. The profile maintains central stability in accordance with the Rayleigh criterion, while peripheral centrifugal instability reflects the transient and dissipative nature of dust devils. The model captures dust lifting and charge separation in dust devils, linking strong updrafts and confined flow to enhanced electrification and particle transport.</div></div>","PeriodicalId":11985,"journal":{"name":"European Journal of Mechanics B-fluids","volume":"117 ","pages":"Article 204451"},"PeriodicalIF":2.5,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145880202","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

Macroscopic quantum-like behavior of a turbulent jet 湍流射流的宏观类量子行为

IF 2.5 3区工程技术

European Journal of Mechanics B-fluids Pub Date : 2026-05-01 Epub Date: 2025-11-29 DOI: 10.1016/j.euromechflu.2025.204427

Laurent Nottale, Thierry Lehner

{"title":"Macroscopic quantum-like behavior of a turbulent jet","authors":"Laurent Nottale, Thierry Lehner","doi":"10.1016/j.euromechflu.2025.204427","DOIUrl":"10.1016/j.euromechflu.2025.204427","url":null,"abstract":"<div><div>We apply the scale-relativity theory of turbulence to round jets. For a flow reaching scales much larger than the integral scale, which is the case in jets, we find that fluid particle trajectories become fractal beyond the integral scale. On this basis, the Navier–Stokes equations can be integrated under the form of a macroscopic Schrödinger-type equation, which is solved in terms of a wave function whose modulus squared yields the concentration profile. The solution obtained is in excellent agreement with the experimentally observed turbulent free jet concentration. Then we have performed a new experiment, in order to put to the test such a macroquantum-like behavior. The free turbulent jet has a natural conic self-similar structure with opening angle <span><math><mrow><msub><mrow><mi>α</mi></mrow><mrow><mi>S</mi></mrow></msub><mo>≈</mo><mn>0</mn><mo>.</mo><mn>235</mn></mrow></math></span>. We have performed an experiment consisting of <em>confining a turbulent jet inside its own cone</em>: this is, according to the scale-relativity approach, a macroscopic analog of a quantum particle in a cylindrical box. Thanks to the infinite potential well thus achieved, excited states can be reached. In the first one, we predict from the Schrödinger equation a vanishing concentration on the centerline of the jet, while it is highest for the free jet. This new theoretical prediction is validated with high statistical significance in our jet experiment, which therefore brings strong support to the existence of macroscopic quantum-like phenomena driven by (effective) nondifferentiability of a medium and its induced fractality.</div></div>","PeriodicalId":11985,"journal":{"name":"European Journal of Mechanics B-fluids","volume":"117 ","pages":"Article 204427"},"PeriodicalIF":2.5,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145683171","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 on the dynamic evolution process of entrainment vortex at the horizontal inlet of a large low-head pump station 某大型低扬程泵站水平进口带涡动态演化过程研究

IF 2.5 3区工程技术

European Journal of Mechanics B-fluids Pub Date : 2026-05-01 Epub Date: 2025-11-26 DOI: 10.1016/j.euromechflu.2025.204426

Fusheng Lv, Pingping Li, Weihua Xiao, Luoping Pan

{"title":"Study on the dynamic evolution process of entrainment vortex at the horizontal inlet of a large low-head pump station","authors":"Fusheng Lv, Pingping Li, Weihua Xiao, Luoping Pan","doi":"10.1016/j.euromechflu.2025.204426","DOIUrl":"10.1016/j.euromechflu.2025.204426","url":null,"abstract":"<div><div>Understanding hydraulic transients during the inlet process of a pump station is crucial for identifying the adverse effects of strong turbulence on its operation. Such an understanding can enhance the overall quality of the pump system and mitigate potential risks associated with hydraulic transients. This paper investigates the formation mechanism of suction vortices in the forebay of a pumping station under high flow rates and their impact on the inflow regime through numerical simulation. By employing the coupled three-dimensional Volume of Fluid (VOF) + Level Set method, the dynamic evolution of the entrained flow vortex was calculated, and the causes and impacts of the vortex on the hydraulic characteristics of the pump station inlet were analyzed. The significant correlation between the development of entrained vortices and the excessive inflow angle caused by severe flow deviation in the forebay was elucidated. This study provides a visualization method for the spatiotemporal evolution of internal vortices at the horizontal inlet of large low-head pumping stations. It aids in identifying the causes of uneven flow and vibration in the inlet system, thus offering theoretical support for the safe operation of pumping stations.</div></div>","PeriodicalId":11985,"journal":{"name":"European Journal of Mechanics B-fluids","volume":"117 ","pages":"Article 204426"},"PeriodicalIF":2.5,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145683173","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

Impact of blood rheology on left heart haemodynamics: Newtonian vs. non-Newtonian modelling 血液流变学对左心血流动力学的影响：牛顿模型与非牛顿模型

IF 2.5 3区工程技术

European Journal of Mechanics B-fluids Pub Date : 2026-05-01 Epub Date: 2025-12-15 DOI: 10.1016/j.euromechflu.2025.204445

Valerio Lupi , Filippo Caruso Lombardi , Martino Andrea Scarpolini , Roberto Verzicco , Francesco Viola

{"title":"Impact of blood rheology on left heart haemodynamics: Newtonian vs. non-Newtonian modelling","authors":"Valerio Lupi , Filippo Caruso Lombardi , Martino Andrea Scarpolini , Roberto Verzicco , Francesco Viola","doi":"10.1016/j.euromechflu.2025.204445","DOIUrl":"10.1016/j.euromechflu.2025.204445","url":null,"abstract":"<div><div>Although blood exhibits non-Newtonian properties, it is often modelled as a Newtonian fluid in numerical studies. However, the impact of this assumption on the accuracy of the predictions of computational models is not thoroughly assessed. For this reason, in this work, we compare the effect of Newtonian and shear-thinning blood rheological models on computational haemodynamics in the left heart. The analysis is based on the fluid–structure-electrophysiology interaction (FSEI) within a patient-specific anatomy of an individual with low ejection fraction to better highlight viscosity changes at low strain rates. Owing to the pulsatile nature of the flow, considerable spatio-temporal variations of the kinematic viscosity are observed for the non-Newtonian case. Integral quantities as well as blood pressure within the cardiac chambers are found to be weakly affected by the rheological model. Substantial differences are reported, instead, between the Newtonian and non-Newtonian cases, for the wall shear stress and local haemolysis index since they are sensitive to the local kinematic viscosity, which decreases within the shear layers of the systolic and diastolic jets, as well as in the near-wall regions.</div></div>","PeriodicalId":11985,"journal":{"name":"European Journal of Mechanics B-fluids","volume":"117 ","pages":"Article 204445"},"PeriodicalIF":2.5,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145837008","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

Electron acoustic solitary wave in quantum plasmas with Kappa electrons 具有Kappa电子的量子等离子体中的电子声孤波

IF 2.5 3区工程技术

European Journal of Mechanics B-fluids Pub Date : 2026-05-01 Epub Date: 2025-12-23 DOI: 10.1016/j.euromechflu.2025.204449

Aakanksha Singh, Punit Kumar

引用次数: 0