Rheologica Acta最新文献_第9页

Hydrodynamical characteristics of a pair of elliptical squirmers in a channel flow of power-law fluids 幂律流体通道流中一对椭圆蠕动器的流体力学特性

IF 2.3 3区工程技术

Rheologica Acta Pub Date : 2023-12-05 DOI: 10.1007/s00397-023-01420-0

Chen Liu, Jianzhong Lin, Zhenyu Ouyang

{"title":"Hydrodynamical characteristics of a pair of elliptical squirmers in a channel flow of power-law fluids","authors":"Chen Liu, Jianzhong Lin, Zhenyu Ouyang","doi":"10.1007/s00397-023-01420-0","DOIUrl":"10.1007/s00397-023-01420-0","url":null,"abstract":"<p>The locomotion state and motion type of elliptical squirmers in a channel flow of power-law fluids are simulated numerically. Three locomotion states (independent, coupled, related) and three types of motions (upstream, intermediate, downstream) for pairs of squirmers are found and identified. The effect of height difference (0.5 ~ 10) between the initial positions of two squirmers, aspect ratio (0.3 ~ 1.0), particle Reynolds numbers (0.5 ~ 10), self-propelling strength of the squirmers (− 9 to 9), and power-law index (0.4 ~ 1.5) of the fluid on the locomotion state and motion type of a pair of squirmers are explored, and the corresponding hydrodynamical characteristics are analyzed in detail. Head-to-head coupled structures and body-to-body coupled structures are observed for a pair of pullers and a pair of pushers, respectively. It is found that coupled structures are easy to be broken for squirmers with larger aspect ratio or larger particle Reynolds number and self-propelling strength. The movement characteristics of squirmers are closely related to the initial positions of squirmers in strong shear-thinning fluid, but not to the initial positions in strong shear-thickening fluid. The dependence of viscosity on shear will also significantly affect the flow velocity, thus changing the motion type of squirmers.</p>","PeriodicalId":755,"journal":{"name":"Rheologica Acta","volume":"63 1","pages":"61 - 78"},"PeriodicalIF":2.3,"publicationDate":"2023-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138546548","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

Machine learning methods for particle stress development in suspension Poiseuille flows 悬浮泊泽维尔流中颗粒应力发展的机器学习方法

IF 2.3 3区工程技术

Rheologica Acta Pub Date : 2023-12-02 DOI: 10.1007/s00397-023-01413-z

Amanda A. Howard, Justin Dong, Ravi Patel, Marta D’Elia, Martin R. Maxey, Panos Stinis

引用次数: 1

A web-based intelligent calculator for predicting viscosity of ethylene–glycol–based nanofluids using an artificial neural network model 基于网络的基于人工神经网络模型的预测乙二醇基纳米流体粘度的智能计算器

IF 2.3 3区工程技术

Rheologica Acta Pub Date : 2023-12-01 DOI: 10.1007/s00397-023-01425-9

Walaeddine Maaoui, Zouhaier Mehrez, Mustapha Najjari

{"title":"A web-based intelligent calculator for predicting viscosity of ethylene–glycol–based nanofluids using an artificial neural network model","authors":"Walaeddine Maaoui, Zouhaier Mehrez, Mustapha Najjari","doi":"10.1007/s00397-023-01425-9","DOIUrl":"10.1007/s00397-023-01425-9","url":null,"abstract":"<div><p>This study presents the development of an artificial neural network (ANN) model to predict the viscosity of ethylene–glycol based nanofluids with different types of nanoparticles using four input parameters: nanoparticle type, size, concentration, and temperature of measurement. The model was trained and validated using 470 experimental measurements. The ANN model demonstrated high accuracy in predicting the viscosity of nanofluids. The obtained statistical error metrics between the measured and predicted values of viscosity were found to be very low. MAPE values were equal to 1.19% and 2.33% for training and testing respectively. The developed model can help researchers to better understand EG-based nanofluids viscosity behavior, and this could be considered as a good step forward to help researchers design new nanofluids with enhanced properties. To make the model more accessible for engineers and researchers, a user-friendly web application was developed using Angular and Django, allowing users to input parameters and obtain viscosity predictions without dealing with complex code. The web application offers multiple output options, including figures, tables, and Excel files. This multidisciplinary research study combines web technology, data science, and fluid mechanics to provide a valuable tool to predict nanofluids’ viscosity for different input parameters.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":755,"journal":{"name":"Rheologica Acta","volume":"63 1","pages":"49 - 60"},"PeriodicalIF":2.3,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138504527","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

A novel approach for the fractional SLS material model experimental identification 分数阶SLS材料模型实验识别的新方法

IF 2.3 3区工程技术

Rheologica Acta Pub Date : 2023-12-01 DOI: 10.1007/s00397-023-01422-y

Stefano Amadori, Giuseppe Catania

{"title":"A novel approach for the fractional SLS material model experimental identification","authors":"Stefano Amadori, Giuseppe Catania","doi":"10.1007/s00397-023-01422-y","DOIUrl":"10.1007/s00397-023-01422-y","url":null,"abstract":"<div><p>A multi-step, iterative technique for the local non-parametric identification of the standard linear solid (SLS) material model employing fractional order time differential operators is presented. Test input data consists of a set of identified material complex modulus values estimated at different frequency values, obtained from input–output experimental measurements made on a material specimen by means of forced harmonic excitation and from experimental measurements made on the same specimen in quasi-static relaxation conditions. The proposed technique is mainly based on an algebraic procedure leading to the solution of an overdetermined system of linear equations, in order to get the optimal value of the model unknown parameters. The procedure is non-parametric, since the SLS model order is initially unknown. The optimal model size can be found by evaluating the stability properties of the solution associated to any model size and by automatically discarding computational, non-physical contributions. The identification procedure is first validated by means of numerically simulated test data from within known model examples, and then it is applied to some experimentally obtained test data associated to different materials.</p></div>","PeriodicalId":755,"journal":{"name":"Rheologica Acta","volume":"63 1","pages":"33 - 47"},"PeriodicalIF":2.3,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00397-023-01422-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138504526","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

Study of the electroosmotic flow of a structured fluid with a new generalized rheological model 用一种新的广义流变模型研究结构流体的电渗透流动

IF 2.3 3区工程技术

Rheologica Acta Pub Date : 2023-11-27 DOI: 10.1007/s00397-023-01418-8

E. E. Herrera-Valencia, M. L. Sánchez-Villavicencio, C. Soriano-Correa, O. Bautista, L.A. Ramírez-Torres, V. J. Hernández-Abad, F. Calderas

{"title":"Study of the electroosmotic flow of a structured fluid with a new generalized rheological model","authors":"E. E. Herrera-Valencia, M. L. Sánchez-Villavicencio, C. Soriano-Correa, O. Bautista, L.A. Ramírez-Torres, V. J. Hernández-Abad, F. Calderas","doi":"10.1007/s00397-023-01418-8","DOIUrl":"10.1007/s00397-023-01418-8","url":null,"abstract":"<div><p>The electroosmotic flow of a viscoelastic fluid in a capillary system was investigated analytically. The rheology of the fluid was characterized by a novel generalized exponential model equation. The charge density obeys the Boltzmann distribution, which governs the electrical double-layer field and body force generated by the applied electrical field. Mathematically, this scenario can be modeled by the Poisson-Boltzmann partial differential equation, by assuming that the zeta potential is small, i.e., less than 25 mV (Debye-Hückel approximation). Considering a pulsating electric field, the shear viscosity and the alteration in the volumetric flow were presented as a function of the material parameters through the characteristic dimensionless numbers by using an exponential-type generalized rheological model. Thixotropy, shear thinning, yield stress mechanisms, and weight concentration were analyzed through numerical results. Finally, the flow properties and rheology were predicted using experimental data reported elsewhere for worm-like micellar solution of cetyl trimethyl ammonium tosilate (CTAT). The rheological equation of state proposed in this study describes the alterations in the structure resulting from applied forces (tangential and normal). These forces induced a structural evolution (kinetic model) due to the relaxation processes caused by shear strain. It is important to mention that in electroosmotic flows, complex behavior such as (i) thixotropy, (ii) rheopexy, and (iii) shear banding flow is scarcely explained in terms of the change in the structure of the fluid under flow.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":755,"journal":{"name":"Rheologica Acta","volume":"63 1","pages":"3 - 32"},"PeriodicalIF":2.3,"publicationDate":"2023-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00397-023-01418-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138504525","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

Progress and challenges in suspension rheology 悬浮液流变学的进展与挑战

IF 2.3 3区工程技术

Rheologica Acta Pub Date : 2023-11-21 DOI: 10.1007/s00397-023-01421-z

Jeffrey F. Morris

引用次数: 0

Specific viscosity of polymer solutions with large thermal blobs 具有较大热膨胀的聚合物溶液的比粘度

IF 2.3 3区工程技术

Rheologica Acta Pub Date : 2023-11-01 DOI: 10.1007/s00397-023-01419-7

Ralph H. Colby, Aijie Han

引用次数: 0

Data-driven methods in Rheology 流变学中的数据驱动方法

IF 2.3 3区工程技术

Rheologica Acta Pub Date : 2023-10-03 DOI: 10.1007/s00397-023-01416-w

Kyung Hyun Ahn, Safa Jamali

引用次数: 0

Obtaining test-independent values of the dynamic and static yield stresses for time-dependent materials 为随时间变化的材料获取与试验无关的动态和静态屈服应力值

IF 2.3 3区工程技术

Rheologica Acta Pub Date : 2023-09-29 DOI: 10.1007/s00397-023-01414-y

Behbood Abedi, Eliana P. Marín Castaño, Elias C. Rodrigues, Roney Leon Thompson, Paulo R. de Souza Mendes

{"title":"Obtaining test-independent values of the dynamic and static yield stresses for time-dependent materials","authors":"Behbood Abedi, Eliana P. Marín Castaño, Elias C. Rodrigues, Roney Leon Thompson, Paulo R. de Souza Mendes","doi":"10.1007/s00397-023-01414-y","DOIUrl":"10.1007/s00397-023-01414-y","url":null,"abstract":"<div><p>When it comes to the measurement of yield stress, the experimental procedure appears to play a significant role. Using a series of experiments, in which the effects of time dependence and shear banding were identified and taken into account, we determined the dynamic and static yield stresses of the materials as unique, test-independent properties. We studied the shear rheological properties of an aqueous suspension of Laponite<sup>®</sup>, which is a highly time-dependent (thixotropic) material. To minimize the irreversible effect of aging on its material properties, the Laponite<sup>®</sup> dispersion was aged for 347 days under a controlled environment. For comparison, an aqueous solution of Carbopol<sup>®</sup>—a slightly time-dependent material—was also investigated. The peak values of the shear stress evolution in constant shear rate tests were compared with the static and dynamic yield stress values. We noticed that, as the shear rate is reduced the peak stress value tends asymptotically to the dynamic yield stress for the slightly time-dependent material, but to slightly above the static yield stress for the thixotropic material. For the Laponite<sup>®</sup> suspension, at relatively low shear rates, we observed that peak stresses are influenced by shear banding. By simulating stress evolution curves using stress step-changes, we eliminated the influence of shear banding and discovered that the lowest yielding point coincides with the static yield stress. In addition, we provided the complete flow curve for the Laponite<sup>®</sup> suspension, showing the role of the static and dynamic yield stresses, and the unattainable zone which is closely related to steady shear banding effects.</p></div>","PeriodicalId":755,"journal":{"name":"Rheologica Acta","volume":"62 11-12","pages":"665 - 685"},"PeriodicalIF":2.3,"publicationDate":"2023-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135200148","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 combined effect of matrix molecular weight, filler concentration, and filler-matrix interactions on the dynamic viscoelasticity of polydimethylsiloxane/clay composites 基质分子量、填料浓度以及填料与基质相互作用对聚二甲基硅氧烷/粘土复合材料动态粘弹性的综合影响

IF 2.3 3区工程技术

Rheologica Acta Pub Date : 2023-09-23 DOI: 10.1007/s00397-023-01417-9

Akanksha Gavendra, Asima Shaukat

{"title":"The combined effect of matrix molecular weight, filler concentration, and filler-matrix interactions on the dynamic viscoelasticity of polydimethylsiloxane/clay composites","authors":"Akanksha Gavendra, Asima Shaukat","doi":"10.1007/s00397-023-01417-9","DOIUrl":"10.1007/s00397-023-01417-9","url":null,"abstract":"<div><p>The macroscopic properties of particle-filled polymer melts depend sensitively on the state of particle dispersion and the structure and dynamics of the interfacial polymer layer, which, in turn, are governed by factors like polymer molecular weight (<i>M</i><sub><i>w</i></sub>), particle concentration (<i>C</i>), and particle-polymer interfacial interactions. However, the combined effect of these factors on the macroscopic properties is far from fully understood, especially for polymers filled with anisotropic particles. In this work, we investigate the combined effect of <i>M</i><sub><i>w</i></sub>, <i>C</i>, and polymer end-group (methyl, Me or hydroxyl, OH) on the dynamic viscoelastic behavior of polydimethylsiloxane (PDMS)/clay composites. The linear viscoelastic behavior of these composites follows a non-monotonic dependence on <i>M</i><sub><i>w</i></sub>, which varies considerably with a modification in <i>C</i> or the polymer end-group. Furthermore, for both Me-PDMS/clay and OH-PDMS/clay composites, the non-linear tests reveal either strain softening-hardening-softening or sustained softening beyond the linear regime, depending on the combination of <i>C</i> and <i>M</i><sub><i>w</i></sub>. The critical strains for the onset of softening and hardening vary differently with <i>M</i><sub><i>w</i></sub> for different combinations of<i> C</i> and the polymer end-group. Our results suggest that the morphology and rheological behavior of these composites are dictated by a complex interplay of various competing effects, namely, particle agglomeration, interfacial polymer packing and density, entanglements, and bridging interactions. These findings give insight into tailoring the properties of polymer composites by adjusting the combination of <i>C</i>, <i>M</i><sub><i>w</i></sub>, and particle-polymer interactions.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":755,"journal":{"name":"Rheologica Acta","volume":"62 11-12","pages":"641 - 663"},"PeriodicalIF":2.3,"publicationDate":"2023-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135957937","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