scholarly journals On solution existence of MHD Casson nanofluid transportation across an extending cylinder through porous media and evaluation of priori bounds

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sohaib Abdal ◽  
Sajjad Hussain ◽  
Imran Siddique ◽  
Ali Ahmadian ◽  
Massimiliano Ferrara
Keyword(s):  
Porous Matrix ◽  
Momentum Equation ◽  
Flow Speed ◽  
Existence Of Solution ◽  
Similarity Functions ◽  
Shooting Technique ◽  
Casson Nanofluid ◽  
Runge Kutta Method ◽  
Large Injection ◽  
Flow Through

AbstractIt is a theoretical exportation for mass transpiration and thermal transportation of Casson nanofluid over an extending cylindrical surface. The Stagnation point flow through porous matrix is influenced by magnetic field of uniform strength. Appropriate similarity functions are availed to yield the transmuted system of leading differential equations. Existence for the solution of momentum equation is proved for various values of Casson parameter $$\beta $$ β , magnetic parameter M, porosity parameter $$K_p$$ K p and Reynolds number Re in two situations of mass transpiration (suction/injuction). The core interest for this study aroused to address some analytical aspects. Therefore, existence of solution is proved and uniqueness of this results is discussed with evaluation of bounds for existence of solution. Results for skin friction factor are established to attain accuracy for large injection values. Thermal and concentration profiles are delineated numerically by applying Runge-Kutta method and shooting technique. The flow speed retards against M, $$\beta $$ β and $$K_p$$ K p for both situations of mass injection and suction. The thermal boundary layer improves with Brownian and thermopherotic diffusions.

scholarly journals On Solution Existence of Mhd Casson Nanofluid Transportation Across an Extending Cylinder Through Porous Media and Evaluation of Priori Bounds

2020 ◽  
Author(s):  
Sohaib Abdal ◽  
Sajjad Hussain ◽  
Imran Siddique
Keyword(s):  
Magnetic Parameter ◽  
Porous Matrix ◽  
Momentum Equation ◽  
Similarity Functions ◽  
Shooting Technique ◽  
Casson Nanofluid ◽  
Uniqueness Results ◽  
Runge Kutta Method ◽  
Large Injection ◽  
Flow Through

It is a theoretical exportation for mass transpiration and thermal transpiration of Casson nanofluid over an extending cylindrical surface. The Stagnation point flow through porous matrix is influenced by magnetic field of form strength. Appropriate similarity functions are availed to yield the transmuted system of leading differential equations. Existence for the solution of momentum equation is proved for various values of Casson parameter β, magnetic parameter M, porosity parameter Kp and Raynolds number Re in two situations of mass transpiration (suction/injuction). Moreover, uniqueness results are discussed and for skin friction factor are established to attain accuracy for large injection values. Thermal and concentration profiles are delineated numerically by applying Runge-Kutta method and shooting technique.

scholarly journals The Importance of Nanoparticles Addition in a Base Fluid Flow through a Porous Medium

2013 ◽  
Vol 8-9 ◽  
pp. 225-234
Author(s):  
Dalia Sabina Cimpean
Keyword(s):  
Porous Medium ◽  
Fluid Flow ◽  
Boundary Conditions ◽  
Mixed Convection ◽  
Mathematical Models ◽  
Base Fluid ◽  
Porous Matrix ◽  
Fluid Properties ◽  
Flow Through ◽  
Energy Equations

The present study is focused on the mixed convection fluid flow through a porous medium, when a different amount of nanoparticles is added in the base fluid. The nanofluid saturates the porous matrix and different situations of the flow between two walls are presented and discussed. Alternatively mathematical models are presented and discussed. A solution of a system which contains the momentum, Darcy and energy equations, together with the boundary conditions involved, is given. The behavior of different nanofluids, such thatAu-water, Ag-waterandFe-wateris graphically illustrated and compared with the previous results.The research target is to observe the substantial increase of the thermophysical fluid properties, when the porous medium issaturated by a nanofluid instead of a classical Newtonian fluid.

Friction factor analysis for a nanofluid circulating in a microchannel filled with a homogeneous porous medium

2022 ◽  
Author(s):  
Francisco Fernando Hernandez ◽  
Federico Mendez ◽  
Jose Joaquin Lizardi ◽  
Ian Guillermo Monsivais
Keyword(s):  
Porous Medium ◽  
Friction Factor ◽  
Porous Matrix ◽  
Velocity Profiles ◽  
Momentum Equation ◽  
Volumetric Concentration ◽  
Forchheimer Equation ◽  
Viscosity Models ◽  
Friction Factors ◽  
Homogeneous Porous Medium

Abstract This work presents the numerical solution for different velocity profiles and friction factors on a rectangular porous microchannel fully saturated by the flow of a nanofluid introducing different viscosity models, including one nanofluid density model. The Darcy-Brinkman-Forchheimer equation was used to solve the momentum equation in the porous medium. The results show that the relative density of the fluid, the nanoparticle diameters and their volumetric concentration have a direct influence on the velocity profiles only when the inertial effects caused by the presence of the porous matrix are important. Finally, it was found that only viscosity models that depend on temperature and nanoparticle diameter reduce the friction factor by seventy percent compared to a base fluid without nanoparticles; furthermore, these models show a velocity reduction of even ten percent along the symmetry axis of the microchannel.

Extended Stokes series: laminar flow through a loosely coiled pipe

1978 ◽  
Vol 86 (1) ◽  
pp. 129-145 ◽  
Author(s):  
Milton Van Dyke
Keyword(s):  
Laminar Flow ◽  
Flow Speed ◽  
Square Root ◽  
Mean Flow ◽  
Dean Number ◽  
Curvature Ratio ◽  
Wide Range ◽  
Square Root Singularity ◽  
Flow Through ◽  
The One

Dean's series for steady fully developed laminar flow through a toroidal pipe of small curvature ratio has been extended by computer to 24 terms. Analysis suggests that convergence is limited by a square-root singularity on the negative axis of the square of the Dean number. An Euler transformation and extraction of the leading and secondary singularities at infinity render the series accurate for all Dean numbers. For curvature ratios no greater than$\frac{1}{250} $, experimental measurements of the laminar friction factor agree with the theory over a wide range of Dean numbers. In particular, they confirm our conclusion that the friction in a loosely coiled pipe grows asymptotically as the one-quarter power of the Dean number based on mean flow speed. This contradicts a number of incomplete boundary-layer analyses in the literature, which predict a square-root variation.

Macroscopic Simulation of Pedestrian Flow through a Bottleneck

2011 ◽  
Vol 97-98 ◽  
pp. 1168-1175 ◽  
Author(s):  
Yan Qun Jiang ◽  
Peng Zhang
Keyword(s):  
Traffic Congestion ◽  
Mass Conservation ◽  
Flow Speed ◽  
Conservation Equation ◽  
Comfort Level ◽  
Macroscopic Model ◽  
Pedestrian Flow ◽  
Macroscopic Simulation ◽  
Flow Through ◽  
Mass Conservation Equation

The paper deals with the macroscopic type modelling of the unidirectional pedestrian flow moving through a corridor with a bottleneck. The macroscopic model of pedestrian flow is the two-dimensional Lighthill-Whitham-Richards model described as a mass conservation equation. The characteristic feature of pedestrian route choice is that pedestrians in the corridor try to minimize the instantaneous travel time and improve the comfort level. The model equation is solved numerically by the discontinuous Galerkin method. Numerical results visualize the ability of the model to predict macroscopic characteristics of pedestrian flow through bottlenecks, i.e. the spatial distribution of the flow speed and density, as well as the formation and dissipation of traffic congestion in the corridor. They also validate that congestion is caused by the limited capacity of the bottleneck.

scholarly journals Numerical solution of hydromagnetic peristaltic flow in a porous-saturated heated channel

2019 ◽  
Vol 23 (5 Part B) ◽  
pp. 3075-3091 ◽  
Author(s):  
Raheel Ahmed ◽  
Nasir Ali
Keyword(s):  
Flow Velocity ◽  
Mass Concentration ◽  
Porous Matrix ◽  
Momentum Equation ◽  
Radius Of Curvature ◽  
Governing Equations ◽  
Long Wavelength ◽  
Implicit Finite Difference Scheme ◽  
Permeability Parameter ◽  
Implicit Finite Difference

The hydromagnetic-flow in sinusoidally heated porous channel is studied by utilizing Darcy-Forchiemmer law with Joule heating effect. The Darcy?s resistance term in the momentum equation is acquired by using modified Darcy?s law. The governing equations for flow velocity, temperature, and mass concentration are developed under lubrication approximation, commonly known as long wavelength assumption in the realm of peristaltic flows. A well-tested implicit finite difference scheme is employed to solve the set of these equations along with appropriate boundary conditions. The governing equations involve important parameters namely, Forchiemmer parameter, dimensionless radius of curvature, permeability parameter, Hartmann, Brinkmann, Schmidt, and Soret numbers. The effect of these important parameters on velocity, temperature and mass concentration is illustrated through graphs. The pressure-flow rate relationship and streamlines are also shown. The presence of porous matrix inside the channel impedes the flow velocity and reduces the peristaltic transport and mingling. Moreover, temperature of the fluid rises with decreasing permeability of porous-matrix and Hartmann number.

scholarly journals Simulation of Bronchial Airflow in COPD Patients

2020 ◽  
Vol 14 (1) ◽  
pp. 20-27
Author(s):  
L.F. Salcedo-Hernandez ◽  
C.R. Torres-Sanmiguel ◽  
G. Urriolagoitia-Sosa ◽  
G.P. Torres-San Miguel ◽  
L.A. Aguilar-Perez ◽  
...  
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Flow Speed ◽  
Chronic Obstructive ◽  
Internal Wall ◽  
Common Risk Factor ◽  
Obstructive Pulmonary Disease ◽  
The Third ◽  
Copd Patients ◽  
Flow Through ◽  
Fluid Interaction

Aim: This research tackles the problem of assessing airflow inside both a healthy and a COPD bronchus ramification, by a Finite Element Method (FEM) computational mode. Background: Chronic Obstructive Pulmonary Disease (COPD) is considered the third leading cause of death worldwide, smoking being the most common risk factor. In the case of emphysema, the appearance of bullae in the upper and middle lobes is frequent. Objective: Bullae tend to increase their size progressively with time, severely clogging bronchi. In this research, bullae with different sizes are modelled as semi-spheres located at the internal wall of a 3D tomographic-based bronchi model. Methods: Several numerical analyses were performed by applying fluid interaction focused on the behaviour of flow through a fifth generations bronchus bifurcation in different cases and degrees of the advance of COPD. Results: The outcome provides the gradients of flow speed and pressure within the bronchus ramification in the considered cases. Conclusion: The methodology herein proposed is applicable to determine the airflow within any patient’s bronchus bifurcation were bullae appear, and thereby to assess and improve the design of custom treatments.

scholarly journals Tracer Test in Fractured Chalk

1993 ◽  
Vol 24 (4) ◽  
pp. 263-274 ◽  
Author(s):  
R. Jakobsen ◽  
K. Høgh Jensen ◽  
K. L. Brettmann
Keyword(s):  
Short Duration ◽  
Transport Mechanism ◽  
Arrival Time ◽  
Porous Matrix ◽  
Tracer Test ◽  
Breakthrough Curves ◽  
Advective Transport ◽  
Long Tail ◽  
Flow Through ◽  
Chalk Aquifer

A two-well tracer test was conducted in eastern Denmark, in which a short duration pulse of lithium chloride was injected into a recharge well and made to flow through a fractured chalk aquifer to a discharge well. The wells were 25 m apart, and the concentration of lithium arriving at the discharge well was monitored at five vertical intervals in the well for a 21-day period. The observed breakthrough curves show a sharp breakthrough front, with an arrival time that is consistent with advective transport through the fractures in the chalk. The breakthrough curves also exhibit a long tail in the falling limb, suggesting the influence of a secondary transport mechanism of diffusion into the porous matrix.

Forced Convection Flow Through an Unsaturated Wellbore

2003 ◽  
Author(s):  
Maria Laura Martins-Costa ◽  
Roge´rio M. Saldanha da Gama
Keyword(s):  
Nonlinear Partial Differential Equations ◽  
Operator Splitting ◽  
Mixture Theory ◽  
Porous Matrix ◽  
Convection Flow ◽  
Theory Approach ◽  
Splitting Technique ◽  
Nonlinear Hyperbolic System ◽  
Implicit Finite Difference Scheme ◽  
Flow Through

This work studies the dynamics of the filling up of a rigid cylindrical shell porous matrix by a Newtonian fluid and the heat transfer associated phenomenon. A mixture theory approach is employed to obtain a preliminary local model for nonisothermal flows through a wellbore. The mixture consists of three overlapping continuous constituents: a solid (porous medium), a liquid and an inert gas included to account for the compressibility of the mixture as a whole. Assuming the convection flow on radial direction only, a set of four nonlinear partial differential equations describes the problem. Its hydrodynamic part — a nonlinear hyperbolic system — is approximated by means of a Glimm’s scheme, combined with an operator splitting technique, while an implicit finite difference scheme is used to simulate the thermal part.

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