arXiv - PHYS - Fluid Dynamics最新文献_第4页

Integrating Neural Operators with Diffusion Models Improves Spectral Representation in Turbulence Modeling 将神经算子与扩散模型相结合可改进湍流建模中的频谱表示法

arXiv - PHYS - Fluid Dynamics Pub Date : 2024-09-13 DOI: arxiv-2409.08477

Vivek Oommen, Aniruddha Bora, Zhen Zhang, George Em Karniadakis

{"title":"Integrating Neural Operators with Diffusion Models Improves Spectral Representation in Turbulence Modeling","authors":"Vivek Oommen, Aniruddha Bora, Zhen Zhang, George Em Karniadakis","doi":"arxiv-2409.08477","DOIUrl":"https://doi.org/arxiv-2409.08477","url":null,"abstract":"We integrate neural operators with diffusion models to address the spectral\u0000limitations of neural operators in surrogate modeling of turbulent flows. While\u0000neural operators offer computational efficiency, they exhibit deficiencies in\u0000capturing high-frequency flow dynamics, resulting in overly smooth\u0000approximations. To overcome this, we condition diffusion models on neural\u0000operators to enhance the resolution of turbulent structures. Our approach is\u0000validated for different neural operators on diverse datasets, including a high\u0000Reynolds number jet flow simulation and experimental Schlieren velocimetry. The\u0000proposed method significantly improves the alignment of predicted energy\u0000spectra with true distributions compared to neural operators alone.\u0000Additionally, proper orthogonal decomposition analysis demonstrates enhanced\u0000spectral fidelity in space-time. This work establishes a new paradigm for\u0000combining generative models with neural operators to advance surrogate modeling\u0000of turbulent systems, and it can be used in other scientific applications that\u0000involve microstructure and high-frequency content. See our project page:\u0000vivekoommen.github.io/NO_DM","PeriodicalId":501125,"journal":{"name":"arXiv - PHYS - Fluid Dynamics","volume":"39 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142267654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Viscoelastic fluid flow in a slowly varying planar contraction: the role of finite extensibility on the pressure drop 缓慢变化的平面收缩中的粘弹性流体流动：有限延伸性对压力降的作用

arXiv - PHYS - Fluid Dynamics Pub Date : 2024-09-12 DOI: arxiv-2409.08150

Bimalendu Mahapatra, Tachin Ruangkriengsin, Howard A. Stone, Evgeniy Boyko

{"title":"Viscoelastic fluid flow in a slowly varying planar contraction: the role of finite extensibility on the pressure drop","authors":"Bimalendu Mahapatra, Tachin Ruangkriengsin, Howard A. Stone, Evgeniy Boyko","doi":"arxiv-2409.08150","DOIUrl":"https://doi.org/arxiv-2409.08150","url":null,"abstract":"We analyze the steady viscoelastic fluid flow in slowly varying contracting\u0000channels of arbitrary shape and present a theory based on the lubrication\u0000approximation for calculating the flow rate-pressure drop relation at low and\u0000high Deborah ($De$) numbers. Unlike most prior theoretical studies leveraging\u0000the Oldroyd-B model, we describe the fluid viscoelasticity using a FENE-CR\u0000model and examine how the polymer chains' finite extensibility impacts the\u0000pressure drop. We employ the low-Deborah-number lubrication analysis to provide\u0000analytical expressions for the pressure drop up to $O(De^4)$. We further\u0000consider the ultra-dilute limit and exploit a one-way coupling between the\u0000parabolic velocity and elastic stresses to calculate the pressure drop of the\u0000FENE-CR fluid for arbitrary values of the Deborah number. Such an approach\u0000allows us to elucidate elastic stress contributions governing the pressure drop\u0000variations and the effect of finite extensibility for all $De$. We validate our\u0000theoretical predictions with two-dimensional numerical simulations and find\u0000excellent agreement. We show that, at low Deborah numbers, the pressure drop of\u0000the FENE-CR fluid monotonically decreases with $De$, similar to the previous\u0000results for the Oldroyd-B and FENE-P fluids. However, at high Deborah numbers,\u0000in contrast to a linear decrease for the Oldroyd-B fluid, the pressure drop of\u0000the FENE-CR fluid exhibits a non-monotonic variation due to finite\u0000extensibility, first decreasing and then increasing with $De$. Nevertheless,\u0000even at sufficiently high Deborah numbers, the pressure drop of the FENE-CR\u0000fluid in the ultra-dilute and lubrication limits is lower than the\u0000corresponding Newtonian pressure drop.","PeriodicalId":501125,"journal":{"name":"arXiv - PHYS - Fluid Dynamics","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142212683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mesh-based Super-Resolution of Fluid Flows with Multiscale Graph Neural Networks 利用多尺度图神经网络对流体流动进行基于网格的超分辨率分析

arXiv - PHYS - Fluid Dynamics Pub Date : 2024-09-12 DOI: arxiv-2409.07769

Shivam Barwey, Pinaki Pal, Saumil Patel, Riccardo Balin, Bethany Lusch, Venkatram Vishwanath, Romit Maulik, Ramesh Balakrishnan

{"title":"Mesh-based Super-Resolution of Fluid Flows with Multiscale Graph Neural Networks","authors":"Shivam Barwey, Pinaki Pal, Saumil Patel, Riccardo Balin, Bethany Lusch, Venkatram Vishwanath, Romit Maulik, Ramesh Balakrishnan","doi":"arxiv-2409.07769","DOIUrl":"https://doi.org/arxiv-2409.07769","url":null,"abstract":"A graph neural network (GNN) approach is introduced in this work which\u0000enables mesh-based three-dimensional super-resolution of fluid flows. In this\u0000framework, the GNN is designed to operate not on the full mesh-based field at\u0000once, but on localized meshes of elements (or cells) directly. To facilitate\u0000mesh-based GNN representations in a manner similar to spectral (or finite)\u0000element discretizations, a baseline GNN layer (termed a message passing layer,\u0000which updates local node properties) is modified to account for synchronization\u0000of coincident graph nodes, rendering compatibility with commonly used\u0000element-based mesh connectivities. The architecture is multiscale in nature,\u0000and is comprised of a combination of coarse-scale and fine-scale message\u0000passing layer sequences (termed processors) separated by a graph unpooling\u0000layer. The coarse-scale processor embeds a query element (alongside a set\u0000number of neighboring coarse elements) into a single latent graph\u0000representation using coarse-scale synchronized message passing over the element\u0000neighborhood, and the fine-scale processor leverages additional message passing\u0000operations on this latent graph to correct for interpolation errors.\u0000Demonstration studies are performed using hexahedral mesh-based data from\u0000Taylor-Green Vortex flow simulations at Reynolds numbers of 1600 and 3200.\u0000Through analysis of both global and local errors, the results ultimately show\u0000how the GNN is able to produce accurate super-resolved fields compared to\u0000targets in both coarse-scale and multiscale model configurations.\u0000Reconstruction errors for fixed architectures were found to increase in\u0000proportion to the Reynolds number, while the inclusion of surrounding coarse\u0000element neighbors was found to improve predictions at Re=1600, but not at\u0000Re=3200.","PeriodicalId":501125,"journal":{"name":"arXiv - PHYS - Fluid Dynamics","volume":"59 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142212687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Enhancing Accuracy of Transition Models for Gas Turbine Applications Through Data-Driven Approaches 通过数据驱动方法提高燃气轮机应用过渡模型的准确性

arXiv - PHYS - Fluid Dynamics Pub Date : 2024-09-12 DOI: arxiv-2409.07803

Harshal D. Akolekar

{"title":"Enhancing Accuracy of Transition Models for Gas Turbine Applications Through Data-Driven Approaches","authors":"Harshal D. Akolekar","doi":"arxiv-2409.07803","DOIUrl":"https://doi.org/arxiv-2409.07803","url":null,"abstract":"Separated flow transition is a very popular phenomenon in gas turbines,\u0000especially low-pressure turbines (LPT). Low-fidelity simulations are often used\u0000for gas turbine design. However, they are unable to predict separated flow\u0000transition accurately. To improve the separated flow transition prediction for\u0000LPTs, the empirical relations that are derived for transition prediction need\u0000to be significantly modified. To achieve this, machine learning approaches are\u0000used to investigate a large number of functional forms using computational\u0000fluid dynamics-driven gene expression programming. These functional forms are\u0000investigated using a multi-expression multi-objective algorithm in terms of\u0000separation onset, transition onset, separation bubble length, wall shear\u0000stress, and pressure coefficient. The models generated after 177 generations\u0000show significant improvements over the baseline result in terms of the above\u0000parameters. All of the models developed improve the wall shear stress\u0000prediction by 40-70% over the baseline laminar kinetic energy model. This\u0000method has immense potential to improve boundary layer transition prediction\u0000for gas turbine applications across several geometries and operating\u0000conditions.","PeriodicalId":501125,"journal":{"name":"arXiv - PHYS - Fluid Dynamics","volume":"273 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142212686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Analog-Based Forecasting of Turbulent Velocity: Relationship between Predictability and Intermittency 基于模拟的湍流速度预测：可预测性与间歇性之间的关系

arXiv - PHYS - Fluid Dynamics Pub Date : 2024-09-12 DOI: arxiv-2409.07792

Ewen FrogéIMT Atlantique - MEE, ODYSSEY, Lab-STICC_OSE, Carlos Granero-BelinchonODYSSEY, IMT Atlantique - MEE, Lab-STICC_OSE, Stéphane G. RouxENS de Lyon, Nicolas B. GarnierPhys-ENS, Thierry ChonavelIMT Atlantique - MEE, Lab-STICC_MATRIX

{"title":"Analog-Based Forecasting of Turbulent Velocity: Relationship between Predictability and Intermittency","authors":"Ewen FrogéIMT Atlantique - MEE, ODYSSEY, Lab-STICC_OSE, Carlos Granero-BelinchonODYSSEY, IMT Atlantique - MEE, Lab-STICC_OSE, Stéphane G. RouxENS de Lyon, Nicolas B. GarnierPhys-ENS, Thierry ChonavelIMT Atlantique - MEE, Lab-STICC_MATRIX","doi":"arxiv-2409.07792","DOIUrl":"https://doi.org/arxiv-2409.07792","url":null,"abstract":"This study evaluates the performance of analog-based methodologies to predict\u0000the longitudinal velocity in a turbulent flow. The data used comes from hot\u0000wire experimental measurements from the Modane wind tunnel. We compared\u0000different methods and explored the impact of varying the number of analogs and\u0000their sizes on prediction accuracy. We illustrate that the innovation, defined\u0000as the difference between the true velocity value and the prediction value,\u0000highlights particularly unpredictable events that we directly link with extreme\u0000events of the velocity gradients and so to intermittency. This result indicates\u0000that while the estimator effectively seizes linear correlations, it fails to\u0000fully capture higher-order dependencies. The innovation underscores the\u0000presence of intermittency, revealing the limitations of current predictive\u0000models and suggesting directions for future improvements in turbulence\u0000forecasting.","PeriodicalId":501125,"journal":{"name":"arXiv - PHYS - Fluid Dynamics","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142212693","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","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 of Particle Clustering and Turbulence Modulation: An Eulerian Approach 粒子集群和湍流调制的直接数值模拟：欧拉方法

arXiv - PHYS - Fluid Dynamics Pub Date : 2024-09-12 DOI: arxiv-2409.07988

Ajay Dhankarghare, Yuval Dagan

{"title":"Direct Numerical Simulation of Particle Clustering and Turbulence Modulation: An Eulerian Approach","authors":"Ajay Dhankarghare, Yuval Dagan","doi":"arxiv-2409.07988","DOIUrl":"https://doi.org/arxiv-2409.07988","url":null,"abstract":"We present a new Eulerian framework for the computation of turbulent\u0000compressible multiphase channel flows, specifically to assess turbulence\u0000modulation by dispersed particulate matter. By combining a modified\u0000low-dissipation numerical scheme for the carrier flow and a quadrature\u0000moment-based method for the particle phase, the turbulent statistics of the\u0000carrier flow and the fluctuations of the particle phase may be obtained as both\u0000are resolved as coupled fields. Using direct numerical simulations, we\u0000demonstrate how this method resolves the turbulent statistics, kinetic energy,\u0000and drag modulation for moderate Reynolds numbers channel flows for the first\u0000time. Validation of our approach to the turbulent clean flow proves the\u0000applicability of the carrier flow low dissipation scheme for relatively low\u0000Mach number compressible flows. This study also rationalizes the computed drag\u0000modulation results using a simplified analytical approach, revealing how the\u0000particle migration towards the wall can affect the drag between the two phases\u0000at different Stokes numbers and particle loadings. Using our Eulerian approach,\u0000we also show the complex interplay between the particles and flow turbulence\u0000fluctuations by capturing the preferential clustering of particles in the\u0000turbulence streaks. This interplay leads to turbulent flow modulations similar\u0000to recent observations reported in prior computational works using Lagrangian\u0000simulations. Our study extends the applicability of Eulerian approaches to\u0000accurately study particle-fluid interactions in compressible turbulent flows by\u0000explicitly calculating the energy equations for both the particle phase and the\u0000carrier fluid motion.","PeriodicalId":501125,"journal":{"name":"arXiv - PHYS - Fluid Dynamics","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142212685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Digital twin of a large-aspect-ratio Rayleigh-Bénard experiment: Role of thermal boundary conditions, measurement errors and uncertainties 大宽比雷利-贝纳德实验的数字孪生：热边界条件、测量误差和不确定性的作用

arXiv - PHYS - Fluid Dynamics Pub Date : 2024-09-12 DOI: arxiv-2409.08263

Philipp Patrick Vieweg, Theo Käufer, Christian Cierpka, Jörg Schumacher

{"title":"Digital twin of a large-aspect-ratio Rayleigh-Bénard experiment: Role of thermal boundary conditions, measurement errors and uncertainties","authors":"Philipp Patrick Vieweg, Theo Käufer, Christian Cierpka, Jörg Schumacher","doi":"arxiv-2409.08263","DOIUrl":"https://doi.org/arxiv-2409.08263","url":null,"abstract":"Albeit laboratory experiments and numerical simulations have proven\u0000themselves successful in enhancing our understanding of long-living large-scale\u0000flow structures in horizontally extended Rayleigh-B'enard convection, some\u0000discrepancies with respect to their size and induced heat transfer remain. This\u0000study traces these discrepancies back to their origins. We start by generating\u0000a digital twin of one standard experimental set-up. This twin is subsequently\u0000simplified in steps to understand the effect of non-ideal thermal boundary\u0000conditions, and the experimental measurement procedure is mimicked using\u0000numerical data. Although this allows explaining the increased observed size of\u0000the flow structures in the experiment relative to past numerical simulations,\u0000our data suggests that the vertical velocity magnitude has been underestimated\u0000in the experiments. A subsequent re-assessment of the latter's original data\u0000reveals an incorrect calibration model. The re-processed data show a relative\u0000increase in $u_{z}$ of roughly $24 %$, resolving the previously observed\u0000discrepancies. This digital twin of a laboratory experiment for thermal\u0000convection at Rayleigh numbers $Ra = left{ 2, 4, 7 right} times 10^{5}$,\u0000a Prandtl number $Pr = 7.1$, and an aspect ratio $Gamma = 25$ highlights the\u0000role of different thermal boundary conditions as well as a reliable calibration\u0000and measurement procedure.","PeriodicalId":501125,"journal":{"name":"arXiv - PHYS - Fluid Dynamics","volume":"99 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142212684","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","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 jet breakup and the resultant drop size distribution: effect of nozzle size and impingement velocity 射流破裂动力学及由此产生的液滴粒度分布：喷嘴尺寸和撞击速度的影响

arXiv - PHYS - Fluid Dynamics Pub Date : 2024-09-11 DOI: arxiv-2409.07056

Pavan Kumar Kirar, Nikhil Kumar, Kirti Chandra Sahu

{"title":"Dynamics of jet breakup and the resultant drop size distribution: effect of nozzle size and impingement velocity","authors":"Pavan Kumar Kirar, Nikhil Kumar, Kirti Chandra Sahu","doi":"arxiv-2409.07056","DOIUrl":"https://doi.org/arxiv-2409.07056","url":null,"abstract":"We conduct systematic experiments to investigate the dynamics of liquid jet\u0000breakup and the resulting droplet size distribution, emphasizing the influence\u0000of liquid jet velocity and needle exit diameter. We precisely control jet\u0000formation using a pressurized water tank equipped with needles of different\u0000sizes. Our study quantifies breakup dynamics through dimensionless parameters\u0000such as the liquid Weber number and the needle exit area ratio. Our key\u0000findings identify three distinct breakup regimes, such as dripping, Rayleigh,\u0000and wind-induced, each dictated by the interplay of surface tension and\u0000aerodynamic forces for various combinations of liquid jet velocity and needle\u0000exit diameter. We construct a regime map to delineate different breakup\u0000behaviours in the We - Ar space. It is observed that lower jet velocities\u0000produce narrow probability density functions for jet breakup length due to\u0000stable jets, whereas higher velocities result in broader distributions.\u0000Increasing jet velocity extends breakup lengths for moderate flow rates due to\u0000enhanced stability in the Rayleigh regime, but higher velocities induce\u0000instability, leading to shorter breakup lengths. Additionally, we analyze the\u0000effects of the needle exit area ratio and liquid Weber number on droplet size\u0000distribution, highlighting the transition from mono-modal to bi-modal\u0000distribution under varying conditions.","PeriodicalId":501125,"journal":{"name":"arXiv - PHYS - Fluid Dynamics","volume":"59 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142212696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Turbulent skin-friction drag reduction via spanwise forcing at high Reynolds number 在高雷诺数条件下通过跨向强迫降低湍流表皮摩擦阻力

arXiv - PHYS - Fluid Dynamics Pub Date : 2024-09-11 DOI: arxiv-2409.07230

Davide Gatti, Maurizio Quadrio, Alessandro Chiarini, Federica Gattere, Sergio Pirozzoli

{"title":"Turbulent skin-friction drag reduction via spanwise forcing at high Reynolds number","authors":"Davide Gatti, Maurizio Quadrio, Alessandro Chiarini, Federica Gattere, Sergio Pirozzoli","doi":"arxiv-2409.07230","DOIUrl":"https://doi.org/arxiv-2409.07230","url":null,"abstract":"We address the Reynolds-number dependence of the turbulent skin-friction drag\u0000reduction induced by streamwise-travelling waves of spanwise wall oscillations.\u0000The study relies on direct numerical simulations of drag-reduced flows in a\u0000plane open channel at friction Reynolds numbers in the range $1000 le Re_tau\u0000le 6000$, which is the widest range considered so far in simulations with\u0000spanwise forcing. Our results corroborate the validity of the predictive model\u0000proposed by Gatti & Quadrio, J. Fluid Mech. (2016): regardless of the control\u0000parameters, the drag reduction decreases monotonically with $Re$, at a rate\u0000that depends on the drag reduction itself and on the skin-friction of the\u0000uncontrolled flow. We do not find evidence in support of the results of Marusic\u0000et al., Nat. Comm. (2021), which instead report by experiments an increase of\u0000the drag reduction with $Re$ in turbulent boundary layers, for control\u0000parameters that target low-frequency, outer-scaled motions. Possible\u0000explanations for this discrepancy are provided, including obvious differences\u0000between open channel flows and boundary layers, and possible limitations of\u0000laboratory experiments.","PeriodicalId":501125,"journal":{"name":"arXiv - PHYS - Fluid Dynamics","volume":"273 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142212695","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Inertial forces and elastohydrodynamic interaction of spherical particles in wall-bounded sedimentation experiments at low particle Reynolds number 低颗粒雷诺数下壁界沉积实验中球形颗粒的惯性力和弹流相互作用

arXiv - PHYS - Fluid Dynamics Pub Date : 2024-09-11 DOI: arxiv-2409.07209

Isabell Noichl, Clarissa Schönecker

{"title":"Inertial forces and elastohydrodynamic interaction of spherical particles in wall-bounded sedimentation experiments at low particle Reynolds number","authors":"Isabell Noichl, Clarissa Schönecker","doi":"arxiv-2409.07209","DOIUrl":"https://doi.org/arxiv-2409.07209","url":null,"abstract":"Wall-bounded sedimentation of spherical particles at low particle Reynolds\u0000numbers $Re_text{P}lessapprox 0.1$ under the influence of elastic deformation\u0000was investigated experimentally. The complete kinematics of both elastic and\u0000rigid spheres sedimenting from rest near a rigid or an elastic plane wall in a\u0000rectangular duct were recorded. Several specific phenomena related to both\u0000inertial and elastohydrodynamic effects were identified and discussed. Among\u0000these phenomena is an inertial wall attraction, i.e., particles approach the\u0000wall while being accelerated from rest. It was found, that this initial\u0000attraction was a universal, purely hydrodynamic phenomenon which occurred in\u0000all experiments at $Re_text{P}lessapprox 0.1$. After the initial stage, rigid\u0000spheres sedimenting at $Re_text{P}approx O(10^{-1}$) near the wall behaved in\u0000the classical way, showing linear migration due to hydrodynamic lift forces.\u0000Non-classic evolution of the particle velocity with respect to the wall\u0000distance was observed for both rigid and elastic spheres sedimenting at\u0000$Re_text{P}approx O(10^{-2}$). Sedimentation was persistently unsteady and\u0000the spheres decelerated although the wall distance was increased. Another\u0000phenomenon is that very soft spheres showed instationarities superimposed by\u0000nonlinearities. These peculiarities in the kinematics are attributed to the\u0000non-trivial coupling between particle-fluid inertial forces and elastic\u0000effects, i.e., to the existence of elastohydrodynamic memory. Instationarities\u0000were also observed during the sedimentation of rigid spheres along an elastic\u0000wall. For example, in the near-wall region, elastohydrodynamic interactions\u0000damped the dynamics during mass acceleration. Meanwhile, persistent undulating\u0000motion towards the wall was observed, i.e., elastohydrodynamic particle\u0000trapping instead of hydrodynamic lift was observed.","PeriodicalId":501125,"journal":{"name":"arXiv - PHYS - Fluid Dynamics","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142212692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0