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

Mean flow induced by longitudinal libration of a fluid-filled rotating container bounded by two conical surfaces 由两个锥形表面围成的充满液体的旋转容器的纵向弛豫引起的平均流

IF 2.6 3区工程技术

European Journal of Mechanics B-fluids Pub Date : 2024-02-23 DOI: 10.1016/j.euromechflu.2024.02.008

M.V. Kurgansky

引用次数: 0

Spatial estimation of unidirectional wave evolution based on ensemble data assimilation 基于集合数据同化的单向波演变空间估计

IF 2.6 3区工程技术

European Journal of Mechanics B-fluids Pub Date : 2024-02-23 DOI: 10.1016/j.euromechflu.2024.02.006

Zitan Zhang , Tianning Tang , Ye Li

{"title":"Spatial estimation of unidirectional wave evolution based on ensemble data assimilation","authors":"Zitan Zhang , Tianning Tang , Ye Li","doi":"10.1016/j.euromechflu.2024.02.006","DOIUrl":"10.1016/j.euromechflu.2024.02.006","url":null,"abstract":"<div><p>With the limitation of the high sensitivity of nonlinear models to initial conditions, the accurate estimation of wave spatial evolution is difficult to perform at a long distance. At this stage, a helpful approach is to improve the accuracy and robustness of the model through data assimilation technique. A robust data assimilation framework is developed by coupling ensemble Kalman filtering (EnKF) with the nonlinear wave model. The spatial evolution is obtained by numerically integrating the viscous modified Nonlinear Schrödinger (MNLS) equation. The performance of the EnKF-MNLS coupled framework is tested using synthetic data and laboratory measurements. The synthetic data is generated by the MNLS simulation superposing the Gaussian noise. In the synthetic cases, the estimated wave envelopes agree well with the clean solution. The results of laboratory experiments indicate that the EnKF-MNLS framework can improve the accuracy of wave forecasts compared to noised MNLS simulations. This study aims to enhance the noise resistance of the nonlinear wave model in spatial evolution and improve the accuracy of the model forecast.</p></div>","PeriodicalId":11985,"journal":{"name":"European Journal of Mechanics B-fluids","volume":"106 ","pages":"Pages 1-12"},"PeriodicalIF":2.6,"publicationDate":"2024-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139950692","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

Influence of passive deformation in the lift coefficient of a NACA0012 wing model 被动变形对 NACA0012 机翼模型升力系数的影响

IF 2.6 3区工程技术

European Journal of Mechanics B-fluids Pub Date : 2024-02-17 DOI: 10.1016/j.euromechflu.2024.02.007

E. Duran , M. Lorite-Díez , N. Konovalov-Shishov , P. Gutierrez-Castillo , C. del Pino

{"title":"Influence of passive deformation in the lift coefficient of a NACA0012 wing model","authors":"E. Duran , M. Lorite-Díez , N. Konovalov-Shishov , P. Gutierrez-Castillo , C. del Pino","doi":"10.1016/j.euromechflu.2024.02.007","DOIUrl":"10.1016/j.euromechflu.2024.02.007","url":null,"abstract":"<div><p>The extensive use of lightweight materials in aerial vehicle wings involves structural flexibility phenomena that generate non-negligible deformation effects. This influence is not restricted to big aircraft but also plays a role in smaller aeroplanes and Unmanned Aerial Vehicles (UAVs). Here, we conduct wind tunnel experiments to analyze the effect of passive deformation on the wing model lift slopes. To isolate the deformation effect, we compare rigid wings with a NACA0012 airfoil imposing a prescribed spanwise deformation. We study three levels of deformation: non-deformed, around 2% and 4.5% of tip deflection. Also, we consider the effect of the wing length by using three different semi-aspect ratios (1, 2, and 4), so a total of nine rigid wing models have been analyzed for a range of Reynolds number from <span><math><mrow><mn>80</mn><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>3</mn></mrow></msup></mrow></math></span> to <span><math><mrow><mn>160</mn><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>3</mn></mrow></msup></mrow></math></span>. Deformed wing models show an increase in lift coefficient compared to non-deformed wing cases. Both deformation levels exhibit a qualitatively similar lift increment. A correlation to predict lift coefficient slope in a flat plate is adapted for a NACA0012 airfoil and validated using our experimental results and literature data. The adjusted correlation can quantify the deformation effect on the lift slope, which is comparable to using a slightly longer wing model.</p></div>","PeriodicalId":11985,"journal":{"name":"European Journal of Mechanics B-fluids","volume":"105 ","pages":"Pages 338-345"},"PeriodicalIF":2.6,"publicationDate":"2024-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0997754624000323/pdfft?md5=6d0cf1e391a2fe17761da21edc4472b2&pid=1-s2.0-S0997754624000323-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139921809","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Optimization of semi-active hydrofoil propulsion performance based on CFD Taguchi method and neural network 基于 CFD 田口方法和神经网络的半主动水翼推进性能优化

IF 2.6 3区工程技术

European Journal of Mechanics B-fluids Pub Date : 2024-02-16 DOI: 10.1016/j.euromechflu.2024.02.005

Zhenyu Song , Jianyang Zhu , Chao Wang

引用次数: 0

Flow analysis for lateral synthetic jets to remove contaminants from the outer surface of an automobile camera module 用于清除汽车摄像头模块外表面污染物的侧向合成射流的流动分析

IF 2.6 3区工程技术

European Journal of Mechanics B-fluids Pub Date : 2024-02-13 DOI: 10.1016/j.euromechflu.2024.02.004

Jihyeon Park, Jaeik Ko, Ji Hoon Song, Minsuk Choi

引用次数: 0

Modal analysis for incompressible fluid flow 不可压缩流体流动的模态分析

IF 2.6 3区工程技术

European Journal of Mechanics B-fluids Pub Date : 2024-02-12 DOI: 10.1016/j.euromechflu.2024.02.002

Satoshi Ishikawa, Takaaki Yamaoka, Shinya Kijimoto

引用次数: 0

The dynamics of the droplet impact and rebound: A lattice Boltzmann study 液滴撞击和反弹的动力学：晶格玻尔兹曼研究

IF 2.6 3区工程技术

European Journal of Mechanics B-fluids Pub Date : 2024-02-10 DOI: 10.1016/j.euromechflu.2024.02.001

Yawen Deng, Xi Liu, Chengjie Zhan, Zhenhua Chai, Baochang Shi

{"title":"The dynamics of the droplet impact and rebound: A lattice Boltzmann study","authors":"Yawen Deng, Xi Liu, Chengjie Zhan, Zhenhua Chai, Baochang Shi","doi":"10.1016/j.euromechflu.2024.02.001","DOIUrl":"https://doi.org/10.1016/j.euromechflu.2024.02.001","url":null,"abstract":"<div><p>In this work, the droplet impact and rebound behaviors on a flat substrate are comprehensively investigated by using the consistent and conservative phase-field based lattice Boltzmann method, which is robust for the multiphase flow problems with the large density ratios and long-time dynamics. The dynamic behavior of the droplet considered here is governed by five key factors: the contact angle, droplet size, the Bond number, the Reynolds number and the density ratio. The effects of these parameters on the barycenter motion trajectory, contact time, the maximum spreading factor and rebound height are studied, and the results show that the Bond number and the density ratio play the critical roles in the droplet morphology when it impacts the substrate. After the impact process, there are three typical patterns: fragmentation, deposition and rebound, which are mainly controlled by the wettability, the size of droplet and the Bond number. In the rebound process, we focus on the rebound height and the number of rebound, and also give the distribution of pressure inside the droplet and the evolution of pressure before fragmentation. Finally, it is also found that under some certain conditions, the air density has a positive effect on the droplet rebound behavior and a large density ratio of 6400 can be achieved.</p></div>","PeriodicalId":11985,"journal":{"name":"European Journal of Mechanics B-fluids","volume":"105 ","pages":"Pages 313-326"},"PeriodicalIF":2.6,"publicationDate":"2024-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139744176","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

Influence of the turbulent closure for the prediction of the linear response of a flow bounded by a corrugated wall 湍流闭合对预测波纹壁水流线性响应的影响

IF 2.6 3区工程技术

European Journal of Mechanics B-fluids Pub Date : 2024-02-09 DOI: 10.1016/j.euromechflu.2024.01.015

Maxime Stuck , François Chedevergne , Marina Olazabal-Loumé , Jacques Couzi

{"title":"Influence of the turbulent closure for the prediction of the linear response of a flow bounded by a corrugated wall","authors":"Maxime Stuck , François Chedevergne , Marina Olazabal-Loumé , Jacques Couzi","doi":"10.1016/j.euromechflu.2024.01.015","DOIUrl":"https://doi.org/10.1016/j.euromechflu.2024.01.015","url":null,"abstract":"<div><p>We investigate the influence of the turbulent closure in Reynolds-Averaged Navier–Stokes (RANS) simulations for the prediction of the linear response of a turbulent boundary layer developping over a small-amplitude corrugated wall. Experimental studies by Hanratty and co-workers (Zilker et al. 1977; Abrams and Hanratty, 1985; Frederick and Hanratty, 1988) show a phase shift between the wall shear stress and the wall undulation, that depends on the wall wavenumber. Historically, this problem was studied by the means of linear forced response analyses using a mixing length model. It was shown that an <em>ad-hoc</em> correction is required to recover the experimental results (Thorsness et al. 1978; Charru et al. 2013). In this study, we ran Reynolds Averaged Navier–Stokes (RANS) computations using different types of turbulent closures. The results confirm the inadequacy of the Boussinesq assumption, leading to the failure of Eddy Viscosity Models (EVM) to properly recover the wall shear stress phase angle. Moreover, it is shown that a second moment closure performs better in capturing the effects of a small deformation of the wall. Additionally, a general strategy based on the modification of the balance of the closure coefficients of a <span><math><mrow><mi>k</mi><mo>−</mo><mi>ω</mi></mrow></math></span> model is found to be an effective approach to improve the performance of first order turbulence models. We establish corrections adapted to the <span><math><mrow><mi>k</mi><mo>−</mo><mi>ω</mi></mrow></math></span> model which can be seen as a pragmatic way to recover the expected behaviors.</p></div>","PeriodicalId":11985,"journal":{"name":"European Journal of Mechanics B-fluids","volume":"105 ","pages":"Pages 275-284"},"PeriodicalIF":2.6,"publicationDate":"2024-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139732823","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

Vorticity alignment with Lyapunov vectors and rate-of-strain eigenvectors 利用李亚普诺夫矢量和应变速率特征向量进行涡度排列

IF 2.6 3区工程技术

European Journal of Mechanics B-fluids Pub Date : 2024-02-08 DOI: 10.1016/j.euromechflu.2024.02.003

A. Encinas-Bartos, G. Haller

引用次数: 0

Migration of a multi-core compound droplet in a ratchet microchannel 多核化合物液滴在棘轮微通道中的迁移

IF 2.6 3区工程技术

European Journal of Mechanics B-fluids Pub Date : 2024-02-03 DOI: 10.1016/j.euromechflu.2024.01.016

Nang X. Ho , Hung V. Vu , Truong V. Vu

{"title":"Migration of a multi-core compound droplet in a ratchet microchannel","authors":"Nang X. Ho , Hung V. Vu , Truong V. Vu","doi":"10.1016/j.euromechflu.2024.01.016","DOIUrl":"https://doi.org/10.1016/j.euromechflu.2024.01.016","url":null,"abstract":"<div><p>With the unique structure of multi-core compound droplets, they are increasingly used in various industrial production fields, material fabrication, biological sciences, medicine, and other numerous promising large-scale applications. This study focuses on using a front tracking method to study the dynamics of a multi-core compound droplet as it moves within a ratchet microchannel. The dynamics of the multi-core droplet is assessed by deformation (determined by elongation deformation indices, and surface indentation) and the transit time of the droplet within the microchannel. The presence of the ratchet region in the microchannel increases deformation and reduces the transit time of the compound droplets. Increasing the number of ratchets leads to faster droplet motion but has no significant effect on the deformation of the compound droplet. The results indicate that the parameters such as the capillary number, microchannel geometry (i.e., number of ratchets and neck radius), droplet size and structure significantly impact the compound droplet dynamics. The compound droplet radius equal to 0.3 times the microchannel radius results in the most significant elongation deformation. The number of core droplets has minimal effect on the deformation and transit time of the compound droplet. This study provides a profound insight into the dynamics of multi-core compound droplets in a ratchet microchannel and contributes a better understanding of their behavior and potential applications in various fields.</p></div>","PeriodicalId":11985,"journal":{"name":"European Journal of Mechanics B-fluids","volume":"105 ","pages":"Pages 285-294"},"PeriodicalIF":2.6,"publicationDate":"2024-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139732824","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