Design of viscometers corresponding to a universal molecular simulation method

2011 ◽  
Vol 691 ◽  
pp. 461-486 ◽  
Author(s):  
Kaushik Dayal ◽  
Richard D. James
Keyword(s):  
Molecular Simulation ◽  
Compressible Flows ◽  
Incompressible Flows ◽  
Complex Fluids ◽  
Unsteady Flows ◽  
Simulation Method ◽  
Solid State Phys ◽  
Basic Theme ◽  
Conceptual Designs ◽  
Large Families

AbstractWe present conceptual designs of viscometers corresponding to our new exact molecular simulation method (Dayal & James, J. Mech. Phys. Solids, vol. 58 (2), 2010, pp. 145–163). The molecular simulation method is a generalization of the method of Lees & Edwards (J. Phys. C: Solid State Phys., vol. 5, 1972, p. 1921), and includes a three-parameter family of incompressible flows, as well as compressible flows and unsteady flows exhibiting vortex stretching. All fluids are allowed. The method gives a way to simulate these flows using relatively few molecules, in the absence of a constitutive relation describing the fluid. This paper presents conceptual designs for viscometers that produce large families of these flows. The basic theme of this paper is that the flows discussed here are a better way to characterize the properties of complex fluids than the currently available methods, such as those based on viscometric flows.

scholarly journals On mathematical analysis of complex fluids in active hydrodynamics

2021 ◽  
Vol 0 (0) ◽  
pp. 0
Author(s):  
Yazhou Chen ◽  
Dehua Wang ◽  
Rongfang Zhang
Keyword(s):  
Weak Solution ◽  
Mathematical Analysis ◽  
Stochastic Analysis ◽  
Compressible Flows ◽  
Incompressible Flows ◽  
Complex Fluids ◽  
Strong Uniqueness ◽  
Special Issue ◽  
Survey Article ◽  
Active Liquid

<p style='text-indent:20px;'>This is a survey article for this special issue providing a review of the recent results in the mathematical analysis of active hydrodynamics. Both the incompressible and compressible models are discussed for the active liquid crystals in the Landau-de Gennes Q-tensor framework. The mathematical results on the weak solutions, regularity, and weak-strong uniqueness are presented for the incompressible flows. The global existence of weak solution to the compressible flows is recalled. Other related results on the inhomogeneous flows, incompressible limits, and stochastic analysis are also reviewed.</p>

scholarly journals A hybrid molecular-continuum simulation method for incompressible flows in micro/nanofluidic networks

2013 ◽  
Vol 15 (4) ◽  
pp. 541-557 ◽  
Author(s):  
Matthew K. Borg ◽  
Duncan A. Lockerby ◽  
Jason M. Reese
Keyword(s):  
Incompressible Flows ◽  
Simulation Method

New space-averaging procedure for inhomogeneous flow fields using balance equation formulations

2006 ◽  
Vol 220 (9) ◽  
pp. 1363-1374
Author(s):  
S Wattananusorn
Keyword(s):  
Compressible Flows ◽  
Incompressible Flows ◽  
Flow Fields ◽  
Coupling Factor ◽  
Balance Equations ◽  
Mean Velocity ◽  
New Space ◽  
Inhomogeneous Flow ◽  
The Mean ◽  
Dependent Flow

This paper features the possibility of averaging space-dependent flow fields using a coupling factor that links the equations of momentum and energy. The scheme is applied to the mean velocity, which is derived straightforwardly through the continuity equation. It creates a small imbalance, which can be eliminated later completely. Smaller discrepancies in the integration of systems of balance equations for inhomogeneous flow are the consequence. The procedure is verified on various flow patterns, and comparisons are made with other conventional methods and with some available experimental data. Despite investigating only numerical examples of incompressible flows here, the technique, in principle, is capable of dealing with compressible flows as well. Furthermore, the proposed method discards some variables required in other techniques while still providing useful and acceptable results for practical problems.

A Cartesian Explicit Solver for Complex Hydrodynamic Applications

2014 ◽  
Author(s):  
P. Bigay ◽  
A. Bardin ◽  
G. Oger ◽  
D. Le Touzé
Keyword(s):  
Level Set ◽  
Incompressible Flows ◽  
Stokes Equations ◽  
Simulation Method ◽  
Navier Stokes ◽  
Viscous Effects ◽  
Navier Stokes Equations ◽  
Eddy Simulation ◽  
Flow Past A Cylinder ◽  
Explicit Solver

In order to efficiently address complex problems in hydrodynamics, the advances in the development of a new method are presented here. This method aims at finding a good compromise between computational efficiency, accuracy, and easy handling of complex geometries. The chosen method is an Explicit Cartesian Finite Volume method for Hydrodynamics (ECFVH) based on a compressible (hyperbolic) solver, with a ghost-cell method for geometry handling and a Level-set method for the treatment of biphase-flows. The explicit nature of the solver is obtained through a weakly-compressible approach chosen to simulate nearly-incompressible flows. The explicit cell-centered resolution allows for an efficient solving of very large simulations together with a straightforward handling of multi-physics. A characteristic flux method for solving the hyperbolic part of the Navier-Stokes equations is used. The treatment of arbitrary geometries is addressed in the hyperbolic and viscous framework. Viscous effects are computed via a finite difference computation of viscous fluxes and turbulent effects are addressed via a Large-Eddy Simulation method (LES). The Level-Set solver used to handle biphase flows is also presented. The solver is validated on 2-D test cases (flow past a cylinder, 2-D dam break) and future improvements are discussed.

Effective boundary conditions for compressible flows over rough boundaries

2015 ◽  
Vol 25 (07) ◽  
pp. 1257-1297 ◽  
Author(s):  
Giulia Deolmi ◽  
Wolfgang Dahmen ◽  
Siegfried Müller
Keyword(s):  
Boundary Conditions ◽  
Compressible Flows ◽  
Incompressible Flows ◽  
Laminar Flows ◽  
Small Scale ◽  
Reynolds Number Flow ◽  
Effective Boundary ◽  
Effective Boundary Conditions ◽  
High Reynolds ◽  
Rough Boundaries

Simulations of a flow over a roughness are prohibitively expensive for small-scale structures. If the interest is only on some macroscale quantity it will be sufficient to model the influence of the unresolved microscale effects. Such multiscale models rely on an appropriate upscaling strategy. Here the strategy originally developed by Achdou et al. [Effective boundary conditions for laminar flows over periodic rough boundaries, J. Comput. Phys. 147 (1998) 187–218] for incompressible flows is extended to compressible high Reynolds number flow. For proof of concept a laminar flow over a flat plate with partially embedded roughness is simulated. The results are compared with computations on a rough domain.

Toward a robust and general molecular simulation method for computing solid-liquid coexistence

2005 ◽  
Vol 122 (1) ◽  
pp. 014115 ◽  
Author(s):  
David M. Eike ◽  
Joan F. Brennecke ◽  
Edward J. Maginn
Keyword(s):  
Molecular Simulation ◽  
Simulation Method ◽  
Solid Liquid

Building of Poly(Imino Ketone) Chains Model via Molecular Simulation

2011 ◽  
Vol 117-119 ◽  
pp. 1306-1309
Author(s):  
Guan Jun Chang ◽  
Yi Xu ◽  
Hong Ju Hu ◽  
Li Dong Wei ◽  
Shang Fei Sun ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Mechanics ◽  
Molecular Simulation ◽  
Single Molecule ◽  
Three Dimensional ◽  
Periodic Boundary Conditions ◽  
Simulation Method ◽  
Chain Model ◽  
Aggregation State ◽  
Material Studio

Based on different aromatic dibromides and diamines, using Material Studio software and molecular simulation method, Poly(imino ketone) (PIK), Poly(imino ketone ketone) (PIKK), Poly(imino imino ketone) (PIIK), Poly(imino imino ketone ketone) (PIIKK), Flourene-PIIK and Naphthyl-PIIK, respectively, were designed as six different structures of polymers. And through the method of molecular mechanics and molecular dynamics the single-molecule polymer chain model and the aggregation-state model with three-dimensional periodic boundary conditions would be built. Theoretically, the established model has been verified availably after optimization based on molecular mechanics and molecular dynamics.

scholarly journals New Molecular Simulation Method To Determine Both Aluminum and Cation Location in Cationic Zeolites

2017 ◽  
Vol 29 (2) ◽  
pp. 513-523 ◽  
Author(s):  
Marie Jeffroy ◽  
Carlos Nieto-Draghi ◽  
Anne Boutin
Keyword(s):  
Molecular Simulation ◽  
Simulation Method
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