European Journal of Mechanics B-fluids最新文献_第10页

Mixed convection three-dimensional Hiemenz stagnation point flow 混合对流三维希门兹滞止点流动

IF 2.5 3区工程技术

European Journal of Mechanics B-fluids Pub Date : 2025-03-31 DOI: 10.1016/j.euromechflu.2025.204267

Abdul Aziz , Tapas Ray Mahapatra , Sumanta Sidui

{"title":"Mixed convection three-dimensional Hiemenz stagnation point flow","authors":"Abdul Aziz , Tapas Ray Mahapatra , Sumanta Sidui","doi":"10.1016/j.euromechflu.2025.204267","DOIUrl":"10.1016/j.euromechflu.2025.204267","url":null,"abstract":"<div><div>This study delves into the intricate analysis of the steady mixed convection three-dimensional Hiemenz stagnation-point flows over a vertical flat wall immersed in viscous and incompressible fluid. The analysis considers the derivation of a similarity solution, incorporating <span><math><mi>γ</mi></math></span>, indicative of the shear to strain rate ratio, and <span><math><mi>λ</mi></math></span> representing a mixed convection parameter. Numerical solutions are derived meticulously for typical values of <span><math><mi>δ</mi></math></span> (which is function of <span><math><mi>γ</mi></math></span>) and <span><math><mi>λ</mi></math></span> with particular towards discerning critical values <span><math><msub><mrow><mi>λ</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span> especially concerning opposing flow. Asymptotic results are obtained for large values of <span><math><mi>λ</mi></math></span> and <span><math><mi>δ</mi></math></span>. It is observed that dual solutions are present for opposing flows. It is noticed that the critical values <span><math><msub><mrow><mi>λ</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span> of <span><math><mi>λ</mi></math></span> are found in opposing flow, which produce two solution branches by making saddle node bifurcation at <span><math><msub><mrow><mi>λ</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span>. A stability analysis of the steady flow solutions was carried out for different values of mixed convection parameter <span><math><mi>λ</mi></math></span> and it reveals that, the lower solution branches are unstable while the upper solution branches are stable.</div></div>","PeriodicalId":11985,"journal":{"name":"European Journal of Mechanics B-fluids","volume":"113 ","pages":"Article 204267"},"PeriodicalIF":2.5,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143950488","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 flow over a finite wall-mounted circular cylinder at low Reynolds numbers for various aspect ratios 低雷诺数下不同长径比有限壁挂圆柱流动的数值研究

IF 2.5 3区工程技术

European Journal of Mechanics B-fluids Pub Date : 2025-03-28 DOI: 10.1016/j.euromechflu.2025.204266

A. Sohankar, K. Pasha

{"title":"Numerical investigation of flow over a finite wall-mounted circular cylinder at low Reynolds numbers for various aspect ratios","authors":"A. Sohankar, K. Pasha","doi":"10.1016/j.euromechflu.2025.204266","DOIUrl":"10.1016/j.euromechflu.2025.204266","url":null,"abstract":"<div><div>Three-dimensional simulations of flow over and heat transfer from a finite wall-mounted circular cylinder have been conducted for different Reynolds numbers (<em>Re</em> = 1 – 100) and aspect ratios (AR=1–8) at <em>Pr</em>= 0.7, where flow remains steady for most of <em>Re</em> and <em>AR</em> considered. It was found that the computational domain size strongly affects the results, especially at low <em>AR</em> and <em>Re</em>. Thus, for very low Re <em>,</em> where the viscous effects are more dominant, it needs to be employed a more extensive domain size. In contrast, the sensitivity to the domain size decreases with increasing <em>Re</em> and <em>AR</em>. It was also deduced that the drag coefficients decrease by increasing <em>Re</em> for all aspect ratios examined. Furthermore, with the increase of <em>AR</em> but with the same Re <em>,</em> the drag coefficients increase. Some unsteady simulations were also carried out for higher <em>Re</em> in the range of <em>Re</em>= 100–200 for <em>AR</em>= 3–8 to find the critical Reynolds numbers of the onset of vortex shedding (<em>Re</em><sub><em>cr</em></sub>). It is found that the <em>Re</em><sub><em>cr</em></sub> decreases from 195 ± 5–65 ± 5 by increasing <em>AR</em> from 3 to 8, or flow becomes unsteady in lower <em>Re</em> for higher <em>AR</em>. Furthermore<strong>,</strong> the flow structure has been examined for various <em>Re</em> and <em>AR</em>. Different types of vortices, including tip (TV), base (BV), and horseshoe (HV) vortices, as well as Kármán vortex shedding (VS), are observed for a specific range of <em>Re</em> and <em>AR</em>. It is found that contrary to cases with high <em>Re</em>, the aforementioned vortices do not form for all <em>Re</em> (1−100) and <em>AR</em> (1−8) examined.</div></div>","PeriodicalId":11985,"journal":{"name":"European Journal of Mechanics B-fluids","volume":"113 ","pages":"Article 204266"},"PeriodicalIF":2.5,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143950487","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

Modal analysis for incompressible fluid flow: Proposed treatment of inlet and outlet boundary conditions 不可压缩流体流动的模态分析：入口和出口边界条件的建议处理

IF 2.5 3区工程技术

European Journal of Mechanics B-fluids Pub Date : 2025-03-27 DOI: 10.1016/j.euromechflu.2025.204271

Satoshi Ishikawa, Shinya Kijimoto

引用次数: 0

Macroscopic non-linear filtration law for porous media containing cylindrical and spherical inhomogeneities 含圆柱和球面非均匀性多孔介质的宏观非线性过滤规律

IF 2.5 3区工程技术

European Journal of Mechanics B-fluids Pub Date : 2025-03-21 DOI: 10.1016/j.euromechflu.2025.204264

V. Monchiet

引用次数: 0

Experimental study of the drag force applied by supercritical flows on emerging obstacles 超临界气流对新兴障碍物阻力的实验研究

IF 2.5 3区工程技术

European Journal of Mechanics B-fluids Pub Date : 2025-03-13 DOI: 10.1016/j.euromechflu.2025.204262

Okba Mostefaoui , Santiago Gómez , Diego Lopez , Emmanuel Mignot , Nicolas Rivière

{"title":"Experimental study of the drag force applied by supercritical flows on emerging obstacles","authors":"Okba Mostefaoui , Santiago Gómez , Diego Lopez , Emmanuel Mignot , Nicolas Rivière","doi":"10.1016/j.euromechflu.2025.204262","DOIUrl":"10.1016/j.euromechflu.2025.204262","url":null,"abstract":"<div><div>Supercritical open channel flows are typically encountered in mountainous rivers, in tsunami break flood waves, or in steep flooded streets, where they can interact respectively with boulders, bridge piles, buildings, city blocks or urban furniture. Depending on the Froude number of the approaching flow and on the obstacle width compared to the water depth, the flow can either form a wall-jet like bow wave or a detached hydraulic jump, which are expected to modify the force applied on the obstacle. Thus, the present work aims to characterize the steady drag force applied on an emerging obstacle, and to provide a model of the corresponding drag coefficient. To that end, force measurements are performed on parallelepipedal obstacles within supercritical flows, for a wide range of Froude numbers and of obstacle width to water depth ratios. The drag coefficient increases with this ratio and decreases with the Froude number. A momentum-based hydraulic model explains these trends, basing on the specific force arriving on the obstacle. Once combined with the experimental asymptotic values for the very wide obstacles and large Froude numbers, the model results in a semi-empirical equation that provides accurate predictions of the drag coefficient. Strikingly, the same equation is efficient for the two kinds of flow, detached hydraulic jump and wall-jet like bow wave.</div></div>","PeriodicalId":11985,"journal":{"name":"European Journal of Mechanics B-fluids","volume":"113 ","pages":"Article 204262"},"PeriodicalIF":2.5,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143947510","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

Comparative study of Reynolds-averaged Navier–Stokes and partially-averaged Navier–Stokes models for cavitation flows around a hemispherical head-form body 半球形头状体空化流的reynolds平均Navier-Stokes模型与部分平均Navier-Stokes模型的比较研究

IF 2.5 3区工程技术

European Journal of Mechanics B-fluids Pub Date : 2025-03-13 DOI: 10.1016/j.euromechflu.2025.204265

Junyoung Park , Woochan Seok

{"title":"Comparative study of Reynolds-averaged Navier–Stokes and partially-averaged Navier–Stokes models for cavitation flows around a hemispherical head-form body","authors":"Junyoung Park , Woochan Seok","doi":"10.1016/j.euromechflu.2025.204265","DOIUrl":"10.1016/j.euromechflu.2025.204265","url":null,"abstract":"<div><div>Cavitation causes the erosion of marine propellers and induces noise and vibration within the mechanical system. In this study, the results of Reynolds-averaged Navier–Stokes (RANS) and partially-averaged Navier–Stokes (PANS) models for detecting cavitation flows around a three-dimensional (3D) hemispherical head-form body were compared. These turbulence models can accurately depict the unsteady characteristics of cavitation flows. To investigate the effect of these turbulence models on flow characteristics, we analyzed the periodic shedding of the sheet and cloud cavitation. In addition to the shape of the cavity around the body, the pressure, velocity, turbulent kinetic energy, and turbulent viscosity were compared to identify the differences between the turbulent models. An open-source platform OpenFOAM was used for this analysis. The results revealed that the pressure coefficient in the PANS model was consistent with the experimental data. Furthermore, the PANS model provided an accurate depiction of the development process of sheet and cloud cavitation.</div></div>","PeriodicalId":11985,"journal":{"name":"European Journal of Mechanics B-fluids","volume":"113 ","pages":"Article 204265"},"PeriodicalIF":2.5,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143950486","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

LBM simulation of bubble dynamics in a microchannel with multi-hole orifice plate 多孔孔板微通道气泡动力学的LBM模拟

IF 2.5 3区工程技术

European Journal of Mechanics B-fluids Pub Date : 2025-03-11 DOI: 10.1016/j.euromechflu.2025.204260

Jiafu Wan, Hongyi Ding, Nan Wang, Wuhan Dong, Zhiyun Wang

{"title":"LBM simulation of bubble dynamics in a microchannel with multi-hole orifice plate","authors":"Jiafu Wan, Hongyi Ding, Nan Wang, Wuhan Dong, Zhiyun Wang","doi":"10.1016/j.euromechflu.2025.204260","DOIUrl":"10.1016/j.euromechflu.2025.204260","url":null,"abstract":"<div><div>This study employs a lattice Boltzmann method (LBM), incorporating the Allen-Cahn (A-C) phase-field model, to numerically simulate bubble dynamics in a microchannel with a multi-hole orifice plate. The influence of Weber number (<em>We</em>), non-dimensional bubble diameter (<em>γ</em>), and contact angle (<em>θ</em>) on bubble motion characteristics is thoroughly examined. Phenomena such as dynamic deformation, splitting, coalescence, and mass loss of the bubble during its passage through the multi-hole orifice plate are analyzed. Numerical results demonstrate that as the surface tension of the bubble decreases, corresponding to an increase in the Weber number, the bubble’s splitting process is facilitated as it passes through the multi-hole orifice plate. Additionally, two critical Weber numbers are identified in the study, delineating three different behaviors of the bubble as its passage, with these behaviors being influenced by changes in the non-dimensional bubble diameter. An increase in contact angle significantly prolongs the passage time <em>t</em> * , especially at higher <em>We</em> numbers. The most substantial increase of <em>t</em> * occurs at a Weber number of 27.24 when the contact angle shifts from 125 to 150 degrees, reaching a maximum of 64.13 %. Furthermore, the residual mass ratio of bubbles post-passage diminishes, recording its lowest at the highest Weber number and contact angle (<em>We</em> = 27.24, <em>θ</em> = 150°), standing at 0.71.</div></div>","PeriodicalId":11985,"journal":{"name":"European Journal of Mechanics B-fluids","volume":"113 ","pages":"Article 204260"},"PeriodicalIF":2.5,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143947508","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 flow structure of liquid metal pulsating cross flow in-line tube bundles with various pitch-to-diameter ratio 不同节径比下液态金属脉动横流直列管束流动结构分析

IF 2.5 3区工程技术

European Journal of Mechanics B-fluids Pub Date : 2025-03-08 DOI: 10.1016/j.euromechflu.2025.204259

Hantao Jiang, Wenqiang Suo, Yingwen Liu

{"title":"Analysis of flow structure of liquid metal pulsating cross flow in-line tube bundles with various pitch-to-diameter ratio","authors":"Hantao Jiang, Wenqiang Suo, Yingwen Liu","doi":"10.1016/j.euromechflu.2025.204259","DOIUrl":"10.1016/j.euromechflu.2025.204259","url":null,"abstract":"<div><div>In order to further improve the efficiency and safety of tube bundle heat exchangers, liquid metal cross flow tube bundles under pulsating inlet flow conditions are investigated in this paper. The simulation study is carried out using the <em>k-kl-ω</em> turbulence model, which has been validated by previous experimental data, for in-line tube bundles with different arrangements. The numerical studies were carried out for pulsating velocity amplitude of 0.5, frequency of 10, and Re of 20,000 with transverse and streamwise pitch-to-diameter ratios of 1.5, 1.65, and 1.8. The analysis of the circumferential pressure drop factor of the tube bundle reveals that the pulsating flow excites the secondary flow at the back side of the bundle, which strengthens the local flow field, while the increase in global pressure drop is more pronounced at a smaller pitch ratio. Enlarged figure of the local time-averaged flow field show the differential flow behaviors at different pitch ratios, further revealing the obvious asymmetric characteristics of the secondary flow. The local secondary flow time-averaged results show that the first three columns of secondary flow are enhanced more than three times as much as in normal flow. Finally, the time series of secondary flow is analyzed by using power spectral density, continuous wavelet transform, and combined with Gaussian multimodal decomposition to reveal the representative secondary flow change characteristics at the back side of the tube in the first three columns. Finally, the distribution map of vortex structure features under the simulation parameters of this paper is given.</div></div>","PeriodicalId":11985,"journal":{"name":"European Journal of Mechanics B-fluids","volume":"113 ","pages":"Article 204259"},"PeriodicalIF":2.5,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143947507","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

Dynamics of a neutrally-buoyant elliptic particle in a square cavity with two adjacent moving walls: A lattice Boltzmann simulation 具有两个相邻移动壁的方形腔中中性浮力椭圆粒子的动力学：晶格玻尔兹曼模拟

IF 2.5 3区工程技术

European Journal of Mechanics B-fluids Pub Date : 2025-03-08 DOI: 10.1016/j.euromechflu.2025.204261

Taha Rezaee

引用次数: 0

Flow past a porous plate of a new class of fluids with limiting stress: Analytical results and linear stability analysis 一类具有极限应力的新型流体流过多孔板：分析结果和线性稳定性分析

IF 2.5 3区工程技术

European Journal of Mechanics B-fluids Pub Date : 2025-03-04 DOI: 10.1016/j.euromechflu.2025.02.007

Lorenzo Fusi , Kumbakonam R. Rajagopal

引用次数: 0