scholarly journals Analysis of the 3D non-linear Stokes problem coupled to transport-diffusion for shear-thinning heterogeneous microscale flows, applications to digital rock physics and mucociliary clearance

2019 ◽  
Vol 53 (4) ◽  
pp. 1083-1124 ◽  
Author(s):  
David Sanchez ◽  
Laurène Hume ◽  
Robin Chatelin ◽  
Philippe Poncet
Keyword(s):  
Complex Geometry ◽  
Stokes Problem ◽  
Real Life ◽  
Coupled Model ◽  
Rock Physics ◽  
Shear Thinning ◽  
Fluid Viscosity ◽  
Domain Modeling ◽  
Time Dependent Domain ◽  
Non Linear

This study provides the analysis of the generalized 3D Stokes problem in a time dependent domain, modeling a solid in motion. The fluid viscosity is a non-linear function of the shear-rate and depends on a transported and diffused quantity. This is a natural model of flow at very low Reynolds numbers, typically at the microscale, involving a miscible, heterogeneous and shear-thinning incompressible fluid filling a complex geometry in motion. This one-way coupling is meaningful when the action produced by a solid in motion has a dominant effect on the fluid. Several mathematical aspects are developed. The penalized version of this problem is introduced, involving the penalization of the solid in a deformable motion but defined in a simple geometry (a periodic domain and/or between planes), which is of crucial interest for many numerical methods. All the equations of this partial differential system are analyzed separately, and then the coupled model is shown to be well-posed and to converge toward the solution of the initial problem. In order to illustrate the pertinence of such models, two meaningful micrometer scale real-life problems are presented: on the one hand, the dynamics of a polymer percolating the pores of a real rock and miscible in water; on the other hand, the dynamics of the strongly heterogeneous mucus bio-film, covering the human lungs surface, propelled by the vibrating ciliated cells. For both these examples the mathematical hypothesis are satisfied.

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.

Study on the Flow Characteristics of Shengli Oilfield Super Heavy Oil

2017 ◽  
Vol 10 (1) ◽  
pp. 69-78 ◽  
Author(s):  
Wang Shou-long ◽  
Li Ai-fen ◽  
Peng Rui-gang ◽  
Yu Miao ◽  
Fu Shuai-shi
Keyword(s):  
Pressure Drop ◽  
Pressure Gradient ◽  
Heavy Oil ◽  
Flow Characteristics ◽  
Fluid Viscosity ◽  
Linear Flow ◽  
Start Up ◽  
Non Linear ◽  
Core Permeability ◽  
Velocity Pressure

Objective:The rheological properties of oil severely affect the determination of percolation theory, development program, production technology and oil-gathering and transferring process, especially for super heavy oil reservoirs. This paper illustrated the basic seepage morphology of super heavy oil in micro pores based on its rheological characteristics.Methods:The non-linear flow law and start-up pressure gradient of super heavy oil under irreducible water saturation at different temperatures were performed with different permeable sand packs. Meanwhile, the empirical formulas between start-up pressure gradient, the parameters describing the velocity-pressure drop curve and the ratio of gas permeability of a core to fluid viscosity were established.Results:The results demonstrate that temperature and core permeability have significant effect on the non-linear flow characteristics of super heavy oil. The relationship between start-up pressure gradient of oil, the parameters representing the velocity-pressure drop curve and the ratio of core permeability to fluid viscosity could be described as a power function.Conclusion:Above all, the quantitative description of the seepage law of super heavy oil reservoir was proposed in this paper, and finally the empirical diagram for determining the minimum and maximum start-up pressure of heavy oil with different viscosity in different permeable formations was obtained.

Influence of fluid viscosity and flow transition over non-linear filtration through porous media

2021 ◽  
Vol 130 (4) ◽  
Author(s):  
Ashes Banerjee ◽  
Srinivas Pasupuleti ◽  
Mritunjay Kumar Singh ◽  
Dandu Jagan Mohan
Keyword(s):  
Porous Media ◽  
Fluid Viscosity ◽  
Flow Transition ◽  
Non Linear ◽  
Linear Filtration

Multi-Period Virtual Cell Formation: A New Methodology Based on Non-Linear Mixed-Integer Programming Model

2013 ◽  
Vol 278-280 ◽  
pp. 2210-2217
Author(s):  
Jie Lv ◽  
Jing Yuan ◽  
Wen Min Han
Keyword(s):  
Cell Size ◽  
Production Cost ◽  
Dynamic Condition ◽  
Cell Formation ◽  
Real Life ◽  
Mixed Integer ◽  
Virtual Cell ◽  
Work In Process ◽  
Non Linear ◽  
Internal Production

This paper researched on multi-period dynamic virtual cell formation problem, and filled the gap on objectives of previous literatures. A developed 0-1 non-linear mixed-integer mathematical model was proposed, it incorporates real-life parameters like alternative routings, operation sequence, duplicate machine, processing time and machine capacity. The advantage of the model is to embed the function relationship between cell size and internal production cost in the model, thus the effects of set-up cost, work-in-process inventory cost, coordination cost and inventory handling cost on VCMS are acted on the model. Finally a numerical example solved by Lingo11.0 software package was presented to verify the model and related discussion was made. The results show that the cell size changes as time in dynamic condition and different scenarios of internal production cost can obtain different cell configurations.

Large-amplitude unsteady flow in liquid-filled elastic tubes

1967 ◽  
Vol 29 (3) ◽  
pp. 513-538 ◽  
Author(s):  
John H. Olsen ◽  
Ascher H. Shapiro
Keyword(s):  
Water Waves ◽  
Large Amplitude ◽  
Linear Equations ◽  
Perturbation Expansion ◽  
Elastic Tube ◽  
Fluid Viscosity ◽  
Elastic Tubes ◽  
Non Linear ◽  
Laminar And Turbulent Flow ◽  
Large Amplitude Motion

Unsteady, large-amplitude motion of a viscous liquid in a long elastic tube is investigated theoretically and experimentally, in the context of physiological problems of blood flow in the larger arteries. Based on the assumptions of long wavelength and longitudinal tethering, a quasi-one-dimensional model is adopted, in which the tube wall moves only radially, and in which only longitudinal pressure gradients and fluid accelerations are important. The effects of fluid viscosity are treated for both laminar and turbulent flow. The governing non-linear equations are solved analytically in closed form by a perturbation expansion in the amplitude parameter, and, for comparison, by numerical integration of the characteristic curves. The two types of solution are compared with each other and with experimental data. Non-linear effects due to large amplitude motion are found to be not as large as those found in similar problems in gasdynamics and water waves.

scholarly journals Improving Entropy Estimates of Complex Network Topology for the Characterization of Coupling in Dynamical Systems

Entropy ◽  
2018 ◽  
Vol 20 (11) ◽  
pp. 891 ◽  
Author(s):  
Teddy Craciunescu ◽  
Andrea Murari ◽  
Michela Gelfusa
Keyword(s):  
Dynamical Systems ◽  
Southern Oscillation ◽  
Geodesic Distance ◽  
Influenza Pandemic ◽  
Real Life ◽  
Coupled Model ◽  
Model Systems ◽  
Life Problems ◽  
Metric Distance

A new measure for the characterization of interconnected dynamical systems coupling is proposed. The method is based on the representation of time series as weighted cross-visibility networks. The weights are introduced as the metric distance between connected nodes. The structure of the networks, depending on the coupling strength, is quantified via the entropy of the weighted adjacency matrix. The method has been tested on several coupled model systems with different individual properties. The results show that the proposed measure is able to distinguish the degree of coupling of the studied dynamical systems. The original use of the geodesic distance on Gaussian manifolds as a metric distance, which is able to take into account the noise inherently superimposed on the experimental data, provides significantly better results in the calculation of the entropy, improving the reliability of the coupling estimates. The application to the interaction between the El Niño Southern Oscillation (ENSO) and the Indian Ocean Dipole and to the influence of ENSO on influenza pandemic occurrence illustrates the potential of the method for real-life problems.

ENHANCING THE SYSTEM DYNAMICS MODELING PROCESS WITH A DOMAIN MODELING METHOD

2013 ◽  
Vol 22 (02) ◽  
pp. 1350011 ◽  
Author(s):  
FIONA P. TULINAYO ◽  
PATRICK VAN BOMMEL ◽  
H. A. (ERIK) PROPER
Keyword(s):  
System Dynamics ◽  
Real Life ◽  
Modeling Method ◽  
Flow Diagram ◽  
Domain Modeling ◽  
Dynamics Modeling ◽  
Organizational Settings ◽  
National Medical ◽  
Modeling Process ◽  
Object Role Modeling

Defining complex system dynamics (SD) models in complex organizational settings is hard. This is so because the numbers of variables to consider are many and the question of causation is complicated to untangle. Second, SD models are ambiguous and hard to conceptualize. In this paper, we explore the use of a domain modeling method object-role modeling (ORM) in the process of developing SD models. We do so, because domain modeling methods help to identify relationships among entities within the scope of the problem domain and provide a structural view of the domain. The addition of a domain modeling method to the process of developing SD models is to improve SD model conceptualization, enable transformation and reuse of information plus underpin SD with a domain modeling method that allows creation of database. To realize this, we come up with a procedure in our overall research which we refer to as grounded system dynamics (GSD) a combination of ORM and SD. To reason about the combination of SD with a domain modeling method (ORM), we identify and evaluate relationships between their constructs. Basing on the identified relations, ORM to stock and flow diagram (SFD) steps are defined and applied to a real-life case study national medical stores (NMS) situated in Uganda. On completion, we draw conclusions.

Advantages of Spectrally Analyzed Data: Stochastic Models for Automotive Measured Parameters

2014 ◽  
Vol 1036 ◽  
pp. 493-498 ◽  
Author(s):  
Radu Vilău ◽  
Marin Marinescu ◽  
Octavian Alexa ◽  
Florin Oloeriu ◽  
Marian Truta
Keyword(s):  
Dynamic Models ◽  
Real Life ◽  
Stochastic Approach ◽  
Angular Speed ◽  
Point Of View ◽  
Mechanical Parameter ◽  
Complete Analysis ◽  
Measured Parameter ◽  
Useful Signal ◽  
Non Linear

The paper deals with a new approach in data analysis of a measured mechanical parameter. The classic approach is mainly based on the deterministic statistics that cant cover the whole field of a complete analysis. The stochastic approach, to be used in this paper, offers far more information about the mechanical parameter and can take into account the non-linearity of the signal, eventually, the mechanical parameter itself. Starting from the point of view that, in real life, there is no steady evolution of any parameter, we decide to take into account the importance of the non-linear components of any signal. After e thorough investigation, we hope we could make the difference between the noise, as non-linear components of the measured parameter, and the useful non-linear components (e.g. important shocks, typically met within a vehicles transmission). Using the stochastic modeling procedures, we aimed at issuing comprehensive, accurate and valuable dynamic models of the phenomenon. These models cam be used in a large variety of situations, from describing the process, to evaluating the health of a mechanical system and to controlling a real-time process based on the pre-set models (previously drawing a map of the systems normal behavior and permanently assessing the deviation from it and acting accordingly). The data were measured within the transmission system of a military vehicle. Specifically, we have gathered information about torque and angular speed of different shafts of the driveline. As everybody knows, the power flows within any vehicles transmission in transient modes mainly and it is accompanied by plenty of noise. It is rather challenging to separate (filter) the useful signal form the noise but, on the other hand, it is the only way to achieve useful data. Therefore, a spectral analysis is a must, but not the conventional one, which has its drawbacks, but a multi-spectral one, which is able to insulate the noise. Moreover, starting from the analysis developed with this method, mathematical models, both in discrete and continuos time can be achieved. It is easy to notice that the models that we have achieved are featured by a very good accuracy. We could push the data processing even further, getting generalized models that provide the needs we have mentioned before, with respect to the mapping of a normal (averaged) behavior of a system, to be used in controlling procedures.

Non-Linear Analysis of Bio-Structures Through Refined Beam Models

2018 ◽  
Author(s):  
Daniele Guarnera ◽  
Erasmo Carrera ◽  
Ibrahim Kaleel ◽  
Alfonso Pagani ◽  
Marco Petrolo
Keyword(s):  
Complex Geometry ◽  
Local Effect ◽  
The Finite Element Method ◽  
Nonlinear Analyses ◽  
Linear Behavior ◽  
Novel Approach ◽  
Non Linear ◽  
Out Of Plane ◽  
Carrera Unified Formulation ◽  
Linear Material

A novel approach for the analysis of the non-linear behavior of bio-structures is presented here. This method is developed in the framework of the Carrera Unified Formulation (CUF), a higher-order 1D theory according to which the kinematics of the problem depends on the arbitrary expansion of the generalized unknowns. Taylor-like (TE) and Lagrange-like expansion functions (LE) are employed to describe the kinematic field along the cross-section and, the finite element method (FEM) is used to formulate the governing equations. In this work, the effects of material nonlinearities are investigated and, the problem is solved by using the Newton-Raphson method. An atherosclerotic plaque of an artery is introduced as a typical bio-structure with complex geometry and studied for both linear and non-linear material cases. The results from the proposed technique highlight the accuracy of the in-plane and out-of-plane stress/strain distributions for different 1D models. The 3D-like accuracy of local effect predictions, the possibility of dealing with complex geometries, and low computational costs of nonlinear analyses make the present formulation appealing for biomechanical applications.

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