Collision rates of permeable particles in creeping flows

2021 ◽  
Vol 33 (8) ◽  
pp. 083322
Author(s):  
Rodrigo B. Reboucas ◽  
Michael Loewenberg
Keyword(s):  
Creeping Flows

scholarly journals Non-Isothermal Creeping Flows in a Pipeline Network: Existence Results

Symmetry ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1300
Author(s):  
Evgenii S. Baranovskii ◽  
Vyacheslav V. Provotorov ◽  
Mikhail A. Artemov ◽  
Alexey P. Zhabko
Keyword(s):  
Nonlinear Boundary ◽  
Galerkin Approximation ◽  
Large Data ◽  
Temperature Dependent ◽  
Weak Formulation ◽  
Temperature Dependent Viscosity ◽  
Pipeline Network ◽  
Flux Boundary Conditions ◽  
Creeping Flows ◽  
Dependent Viscosity

This paper deals with a 3D mathematical model for the non-isothermal steady-state flow of an incompressible fluid with temperature-dependent viscosity in a pipeline network. Using the pressure and heat flux boundary conditions, as well as the conjugation conditions to satisfy the mass balance in interior junctions of the network, we propose the weak formulation of the nonlinear boundary value problem that arises in the framework of this model. The main result of our work is an existence theorem (in the class of weak solutions) for large data. The proof of this theorem is based on a combination of the Galerkin approximation scheme with one result from the field of topological degrees for odd mappings defined on symmetric domains.

An Improved Assembling Algorithm in Boundary Elements With Galerkin Weighting Applied to Three-Dimensional Stokes Flows

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Sofia Sarraf ◽  
Ezequiel López ◽  
Laura Battaglia ◽  
Gustavo Ríos Rodríguez ◽  
Jorge D'Elía
Keyword(s):  
Boundary Element Method ◽  
Linear System ◽  
Boundary Element ◽  
Numerical Solutions ◽  
Three Dimensional ◽  
Boundary Integral ◽  
Computational Time ◽  
Creeping Flows ◽  
Order Of Magnitude ◽  
Element Method

In the boundary element method (BEM), the Galerkin weighting technique allows to obtain numerical solutions of a boundary integral equation (BIE), giving the Galerkin boundary element method (GBEM). In three-dimensional (3D) spatial domains, the nested double surface integration of GBEM leads to a significantly larger computational time for assembling the linear system than with the standard collocation method. In practice, the computational time is roughly an order of magnitude larger, thus limiting the use of GBEM in 3D engineering problems. The standard approach for reducing the computational time of the linear system assembling is to skip integrations whenever possible. In this work, a modified assembling algorithm for the element matrices in GBEM is proposed for solving integral kernels that depend on the exterior unit normal. This algorithm is based on kernels symmetries at the element level and not on the flow nor in the mesh. It is applied to a BIE that models external creeping flows around 3D closed bodies using second-order kernels, and it is implemented using OpenMP. For these BIEs, the modified algorithm is on average 32% faster than the original one.

scholarly journals Periodic and Chaotic Orbits of Plane-Confined Micro-rotors in Creeping Flows

2015 ◽  
Vol 25 (5) ◽  
pp. 1111-1123 ◽  
Author(s):  
Enkeleida Lushi ◽  
Petia M. Vlahovska
Keyword(s):  
Chaotic Orbits ◽  
Creeping Flows

scholarly journals Optimal Boundary Control of Non-Isothermal Viscous Fluid Flow

Fluids ◽  
2019 ◽  
Vol 4 (3) ◽  
pp. 133 ◽  
Author(s):  
Evgenii S. Baranovskii ◽  
Anastasia A. Domnich ◽  
Mikhail A. Artemov
Keyword(s):  
Control Parameters ◽  
Marginal Function ◽  
Weak Formulation ◽  
Existence Of Weak Solutions ◽  
Viscous Fluid Flow ◽  
Lower Semi ◽  
Locally Lipschitz ◽  
Creeping Flows ◽  
Flow Domain ◽  
The Mathematical Model

We study an optimal control problem for the mathematical model that describes steady non-isothermal creeping flows of an incompressible fluid through a locally Lipschitz bounded domain. The control parameters are the pressure and the temperature on the in-flow and out-flow parts of the boundary of the flow domain. We propose the weak formulation of the problem and prove the existence of weak solutions that minimize a given cost functional. It is also shown that the marginal function of this control system is lower semi-continuous.

scholarly journals Cytoskeletal Strains in Modeled Optohydrodynamically Stressed Healthy and Diseased Biological Cells

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Sean S. Kohles ◽  
Yu Liang ◽  
Asit K. Saha
Keyword(s):  
Optical Tweezers ◽  
Computational Simulation ◽  
Three Dimensional ◽  
Cellular Membrane ◽  
Three Dimensions ◽  
Cellular Mechanics ◽  
Health Maintenance ◽  
Full Field ◽  
Creeping Flows ◽  
Distinct Disease

Controlled external chemomechanical stimuli have been shown to influence cellular and tissue regeneration/degeneration, especially with regards to distinct disease sequelae or health maintenance. Recently, a unique three-dimensional stress state was mathematically derived to describe the experimental stresses applied to isolated living cells suspended in an optohydrodynamic trap (optical tweezers combined with microfluidics). These formulae were previously developed in two and three dimensions from the fundamental equations describing creeping flows past a suspended sphere. The objective of the current study is to determine the full-field cellular strain response due to the applied three-dimensional stress environment through a multiphysics computational simulation. In this investigation, the multiscale cytoskeletal structures are modeled as homogeneous, isotropic, and linearly elastic. The resulting computational biophysics can be directly compared with experimental strain measurements, other modeling interpretations of cellular mechanics including the liquid drop theory, and biokinetic models of biomolecule dynamics. The described multiphysics computational framework will facilitate more realistic cytoskeletal model interpretations, whose intracellular structures can be distinctly defined, including the cellular membrane substructures, nucleus, and organelles.

scholarly journals Bacterial floc mediated rapid streamer formation in creeping flows

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Mahtab Hassanpourfard ◽  
Zahra Nikakhtari ◽  
Ranajay Ghosh ◽  
Siddhartha Das ◽  
Thomas Thundat ◽  
...  
Keyword(s):  
Creeping Flows

Electroosmotically driven creeping flows in a wavy microchannel

2008 ◽  
Vol 6 (1) ◽  
pp. 37-52 ◽  
Author(s):  
Zheng Xia ◽  
Renwei Mei ◽  
Mark Sheplak ◽  
Z. Hugh Fan
Keyword(s):  
Creeping Flows

Kinetic alpha effect in viscosity stratified creeping flows

1995 ◽  
Vol 7 (8) ◽  
pp. 1866-1871 ◽  
Author(s):  
Igor Kliakhandler ◽  
Gregory Sivashinsky
Keyword(s):  
Creeping Flows ◽  
Alpha Effect

scholarly journals Laminar momentum jets in a stratified fluid

1971 ◽  
Vol 45 (3) ◽  
pp. 561-574 ◽  
Author(s):  
E. J. List
Keyword(s):  
Fourier Transforms ◽  
Equations Of Motion ◽  
Finite Thickness ◽  
Three Dimensional ◽  
Stratified Fluid ◽  
Integral Representations ◽  
Return Flow ◽  
Horizontal Flows ◽  
Creeping Flows ◽  
Finite Distance

Solutions are presented for creeping flows induced by two-and three-dimensional horizontal and vertical momentum jets in a linearly stratified unbounded diffusive viscous fluid. These linear problems are solved by replacing the momentum jet by a body force singularity represented by delta functions and solving the partial differential equations of motion by use of multi-dimensional Fourier transforms. The integral representations for the physical variables are evaluated by a combination of residue theory and numerical integration.The solutions for vertical jets show the jet to be trapped within a layer of finite thickness and systems of rotors to be induced. The horizontal two-dimensional jet solution shows return flows above and below the jet and a pair of rotors. The three-dimensional horizontal jet has no return flow at finite distance and the diffusive contribution is found to be almost negligible in most situations, the primary character of the horizontal flows being given by the non-diffusive solution. Stokes's paradox is found to be non-existent in a density-stratified fluid.

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