Microstructures of fiber suspensions in complex geometry

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Chunlei Ruan ◽  
Jie Ouyang
Keyword(s):  
Fiber Orientation ◽  
Molecular Conformation ◽  
Complex Geometry ◽  
Fluid Model ◽  
Transversely Isotropic ◽  
Fiber Suspensions ◽  
Conformation Tensor ◽  
Planar Contraction ◽  
Volume Method ◽  
Nonlinear Elastic

AbstractEvolutions of molecular conformation and fiber orientation in fiber suspensions are investigated by collocated finite volume method on unstructured triangular meshes. FENE-P (Finite Extensible Nonlinear Elastic Dumbbell model with Peterlin’s approximation) model which is microstructure-based is chosen to describe the polymeric matrix and TIF (transversely isotropic fluid) model is used to calculate the fiber contribution in order to realize the coupling of flow and fiber orientation. Microstructures of molecule and fiber are obtained by analyzing the information of molecular conformation tensor and second-order fiber orientation tensor respectively. Two numerical examples are considered, namely, a planar contraction flow and a planar flow past a confined cylinder. Present results are hoping to give more insight into the microscopic details of complex flows and thus be more helpful for industrial application.

A New Computational Procedure to Predict Transient Hydroplaning Performance of a Tire

2001 ◽  
Vol 29 (1) ◽  
pp. 2-22 ◽  
Author(s):  
T. Okano ◽  
M. Koishi
Keyword(s):  
Complex Geometry ◽  
Fluid Flows ◽  
Computational Procedure ◽  
Vehicle Body ◽  
Fluid Viscosity ◽  
Safe Driving ◽  
Transient Phenomena ◽  
Vehicle Velocity ◽  
Fixed Reference ◽  
Volume Method

Abstract “Hydroplaning characteristics” is one of the key functions for safe driving on wet roads. Since hydroplaning depends on vehicle velocity as well as the tire construction and tread pattern, a predictive simulation tool, which reflects all these effects, is required for effective and precise tire development. A numerical analysis procedure predicting the onset of hydroplaning of a tire, including the effect of vehicle velocity, is proposed in this paper. A commercial explicit-type FEM (finite element method)/FVM (finite volume method) package is used to solve the coupled problems of tire deformation and flow of the surrounding fluid. Tire deformations and fluid flows are solved, using FEM and FVM, respectively. To simulate transient phenomena effectively, vehicle-body-fixed reference-frame is used in the analysis. The proposed analysis can accommodate 1) complex geometry of the tread pattern and 2) rotational effect of tires, which are both important functions of hydroplaning simulation, and also 3) velocity dependency. In the present study, water is assumed to be compressible and also a laminar flow, indeed the fluid viscosity, is not included. To verify the effectiveness of the method, predicted hydroplaning velocities for four different simplified tread patterns are compared with experimental results measured at the proving ground. It is concluded that the proposed numerical method is effective for hydroplaning simulation. Numerical examples are also presented in which the present simulation methods are applied to newly developed prototype tires.

scholarly journals One-way coupling of fiber suspensions through a rotating curved expansion duct

2012 ◽  
Vol 16 (5) ◽  
pp. 1405-1409
Author(s):  
Qi-Hua Zhang ◽  
Fei Tian ◽  
Wei-Dong Shi ◽  
Hua Zhang ◽  
Xiong-Fa Gao
Keyword(s):  
Numerical Method ◽  
Flow Structure ◽  
Fiber Orientation ◽  
Pressure Rise ◽  
Initial Orientation ◽  
Fiber Suspensions ◽  
Inlet Velocity ◽  
The One

A numerical method based on the one-way coupling using the Jeffery equation is presented. The influence of the inlet velocity and the initial orientation on the evolution of fiber orientation is investigated. It is observed that the rotation mainly contributes to the pressure rise, and the flow structure is not obviously altered. Due to the one-way coupling, the effects of the inlet velocity and the rotating rate are insignificant.

Computational Simulation of Synovial Fluid Kinematics of the Scapholunate Joint

2019 ◽  
Vol 24 (02) ◽  
pp. 169-174
Author(s):  
Yoke-Rung Wong ◽  
Sophie Sok Huei Tay ◽  
Ita Suzana Mat Jais ◽  
Hwa-Liang Leo ◽  
Chee-Fui Lieu ◽  
...  
Keyword(s):  
Synovial Fluid ◽  
Fluid Model ◽  
Computational Simulation ◽  
Fluid Pressure ◽  
Pressure Change ◽  
Carpal Bones ◽  
Ligament Injury ◽  
Maximum Pressure ◽  
Fluid Interface ◽  
Volume Method

Background: The interaction between wrist kinematics and synovial fluid pressure has yet to be studied. To our knowledge, this is the first study to determine the effect of scapholunate joint kinematics on synovial fluid pressure change using finite volume method. Methods: The carpal bones of a cadaveric hand were obtained from Computed Tomography (CT) scans. CT images of the carpal bones were segmented and reconstructed into 3D model. The 3D synovial fluid model between the scaphoid and lunate was constructed and then used for computational simulations. The kinematics data of scapholunate joint obtained from radioulnar deviation of the wrist was investigated. Results: It was found that the pressure in synovial fluid varied from -1.68 to 2.64 Pa with maximum pressure located at the scaphoid-fluid interface during the radial deviation. For ulnar deviation, the pressure increased gradually from the scaphoid-fluid interface towards the lunate-fluid interface (-1.37 to 0.37 Pa). Conclusions: This new computational model provides a basis for the study of pathomechanics of ligament injury with the inclusion of synovial fluid.

Mixed convection from a discrete heater in lid-driven enclosures filled with non-Newtonian nanofluids

2016 ◽  
Vol 231 (1) ◽  
pp. 3-16 ◽  
Author(s):  
AM Rashad ◽  
MA Mansour ◽  
Rama Subba Reddy Gorla
Keyword(s):  
Nusselt Number ◽  
Heat Source ◽  
Local Nusselt Number ◽  
Volume Fraction ◽  
Fluid Model ◽  
Convection Flow ◽  
Viscosity Parameter ◽  
Volumetric Rate ◽  
Vertical Walls ◽  
Volume Method

The transport mechanism of laminar combined convection flow of an incompressible viscous non-Newtonian nanofluid in a shear- and buoyancy-driven enclosure has been investigated in this article. The micropolar fluid model is used for the rheological behavior of the non-Newtonian fluid. A heat source with constant volumetric rate is attached in a part of the bottom wall and the remaining parts are thermally insulated. The vertical walls of the cavity are considered to be adiabatic, while the top wall is cooled and moves from left to right with uniform velocity. The thermal conductivity and the dynamic viscosity of the nanofluid are represented by different experimental correlations that are suitable to each nanoparticles. The finite volume method is applied to solve the dimensionless form of the governing equations. A discussion is provided for the effects of the governing parameters on the local Nusselt number and average Nusselt number along the heat source. It is found that an increase in the vortex-viscosity parameter causes a reduction in the local Nusselt number. As the vortex-viscosity parameter increases by 10 times from 0.5 to 5, the Nusselt number reduces by 15%. Additionally, as the nanoparticle volume fraction increases, the rate of heat transfer increases. As the volume fraction increases by 100% from 0.1 to 0.2, the Nusselt number increases by 86%.

Numerical model of two-phase mechanical face seal with shallow grooves based on finite volume method

2020 ◽  
Vol 72 (10) ◽  
pp. 1303-1309
Author(s):  
Wenbin Gao ◽  
Weifeng Huang ◽  
Tao Wang ◽  
Ying Liu ◽  
Zhihao Wang ◽  
...  
Keyword(s):  
Flow Field ◽  
Phase Change ◽  
Finite Volume Method ◽  
Peer Review ◽  
Finite Volume ◽  
Fluid Model ◽  
Mechanical Seal ◽  
Two Phase ◽  
Content Type ◽  
Volume Method

Purpose By modeling and analyzing the two-phase mechanical seal of the fan-shaped groove end face, which is prone to phase change, an effective method to study the flow field of the mechanical seal when both cavitation and boiling exist simultaneously is found. Design/methodology/approach Based on the finite volume method, a fluid model was developed to investigate a two-phase mechanical seal. The validity of the proposed model was verified by comparing with some classical models. Findings By modeling and analyzing the two-phase mechanical seal of the fan-shaped groove end face, which is prone to phase change, the analysis of the gap flow field of the mechanical seal was realized when cavitation and boiling existed simultaneously. Originality/value Based on the model proposed for different conditions, the pressure and phase states in the shallow groove sealing gap were compared. The phase change rate between the mechanical seal faces was also investigated. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-12-2019-0537/

scholarly journals A Multimoment Constrained Finite-Volume Model for Nonhydrostatic Atmospheric Dynamics

2013 ◽  
Vol 141 (4) ◽  
pp. 1216-1240 ◽  
Author(s):  
Xingliang Li ◽  
Chungang Chen ◽  
Xueshun Shen ◽  
Feng Xiao
Keyword(s):  
Finite Volume ◽  
Evolution Equations ◽  
Complex Geometry ◽  
High Order ◽  
Computationally Efficient ◽  
Dynamical Core ◽  
Benchmark Tests ◽  
Volume Method ◽  
Further Development ◽  
Mesh Cell

Abstract The two-dimensional nonhydrostatic compressible dynamical core for the atmosphere has been developed by using a new nodal-type high-order conservative method, the so-called multimoment constrained finite-volume (MCV) method. Different from the conventional finite-volume method, the predicted variables (unknowns) in an MCV scheme are the values at the solution points distributed within each mesh cell. The time evolution equations to update the unknown point values are derived from a set of constraint conditions based on the multimoment concept, where the constraint on the volume-integrated average (VIA) for each mesh cell is cast into a flux form and thus guarantees rigorously the numerical conservation. Two important features make the MCV method particularly attractive as an accurate and practical numerical framework for atmospheric and oceanic modeling. 1) The predicted variables are the nodal values at the solution points that can be flexibly located within a mesh cell (equidistant solution points are used in the present model). It is computationally efficient and provides great convenience in dealing with complex geometry and source terms. 2) High-order and physically consistent formulations can be built by choosing proper constraints in view of not only numerical accuracy and efficiency but also underlying physics. In this paper the authors present a dynamical core that uses the third- and the fourth-order MCV schemes. They have verified the numerical outputs of both schemes by widely used standard benchmark tests and obtained competitive results. The present numerical core provides a promising and practical framework for further development of nonhydrostatic compressible atmospheric models.

scholarly journals One and two-fiber orientation kinetic theories of fiber suspensions

2013 ◽  
Vol 200 ◽  
pp. 17-33 ◽  
Author(s):  
Miroslav Grmela ◽  
Amine Ammar ◽  
Francisco Chinesta
Keyword(s):  
Fiber Orientation ◽  
Fiber Suspensions

Orientation Distribution of Fiber Suspensions in Extensional Flow

2013 ◽  
Vol 785-786 ◽  
pp. 981-984 ◽  
Author(s):  
Zan Huang ◽  
Jin Ping Qu ◽  
Ji Wei Geng ◽  
Shu Feng Zhai ◽  
Shi Kui Jia
Keyword(s):  
Differential Equation ◽  
Distribution Function ◽  
Orientation Distribution Function ◽  
Fiber Orientation ◽  
Extensional Flow ◽  
Three Dimensional ◽  
Orientation Distribution ◽  
Fiber Suspensions ◽  
Short Fibers ◽  
Fiber Orientation Distribution

An orientation distribution function is adopted to describe three-dimensional orientation distribution of short fibers suspensions in extensional flow. A mathematical model of evolution process on fiber orientation distribution function is established by analytical method. Numerical simulation is also used to describe two and three dimensional orientation distribution of fibers. Therefore, analytical solution of differential equation on forecast fiber orientation distribution is deduced.

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