scholarly journals Heat and Mass Transfer in Partially-Layered Cavity with Inner Square conductive Body

2016 ◽  
Vol 13 (1) ◽  
Keyword(s):  
Mass Transfer ◽  
Lewis Number ◽  
Darcy Number ◽  
The Body ◽  
Thermal Conductivity Ratio ◽  
Left Wall ◽  
Conductive Body ◽  
Thermally Conductive ◽  
The Right ◽  
Buoyancy Ratio

This paper investigates the double diffusive natural convection in a partially porous layered enclosed cavity with a thermally conductive square body. The horizontal walls are thermally insulated, the left wall adds heat isothermally into the porous layer, while the right wall is cooled isothermally. The center of the square conductive body is positioned in the center of the cavity in such a way it lays on the porous-fluid interface. The governing equations have been solved using up-wind scheme finite difference method. The Parndtl number, thermal conductivity ratio of the body to fluid, Darcy number, aspect ratio of the square body to the cavity sides have fixed at 6.26, 1, 10-3, 0.5, respectively. The study has been governed by three parameters namely, Lewis number (Le = 1–50), buoyancy ratio (-10 – 10), and Rayleigh number (103 - 106 ). The results have showed that the mass diffusivity ratio, which takes into account non-unity tortuosity ratio (Deff/D = 0.53) has a significant effect on the mass transfer than the unity value. It is found also that Sherwood number is minimal when the buoyancy ratio equals to -0.5, otherwise, it increases with increasing the absolute value of the buoyancy ratio.

Coupled Heat and Mass Transfer by Mixed Convection From a Buried Pipe With Leakage

2003 ◽  
Author(s):  
C. C. Ngo ◽  
F. C. Lai
Keyword(s):  
Mass Transfer ◽  
Nusselt Number ◽  
Mixed Convection ◽  
Heat And Mass Transfer ◽  
Sherwood Number ◽  
Numerical Solutions ◽  
Lewis Number ◽  
The Body ◽  
Buried Pipe ◽  
Buoyancy Ratio

Numerical solutions are presented for combined heat and mass transfer by mixed convection induced from a buried pipe with leakage. Two locations of leakage are considered in the present study: one is on top of the pipe and the other is at the bottom of the pipe. The governing equations formulated in the body-fitted coordinates are solved via the finite difference method. A parametric study has been performed to investigate the effects of Rayleigh number, Peclet number, Lewis number, and buoyancy ratio N on the heat and mass transfer results. It is found that both the Nusselt number and Sherwood number increase for the aiding flows (N > 0) and decrease for the opposing flows (N < 0). For aiding flows, Sherwood number increases with the Lewis number but Nusselt number decreases with the Lewis number.

scholarly journals Double-Diffusive of Natural Convection in an Inclined Porous Square Domain Generalized Model

2019 ◽  
Vol 12 (3) ◽  
pp. 151-160
Author(s):  
Khaled Al-Farhany ◽  
A. Turan
Keyword(s):  
Natural Convection ◽  
Lewis Number ◽  
Boussinesq Approximation ◽  
Darcy Number ◽  
Governing Equations ◽  
Simpler Algorithm ◽  
Wide Range ◽  
Finite Volume Approach ◽  
Buoyancy Ratio ◽  
Double Diffusive

Numerical investigate of double-diffusive natural convection in an inclined porous square. Two opposing walls of the square cavity are adiabatic; while the other walls are, kept at constant concentrations and temperatures. The Darcy–Forchheimer–Brinkman model is used to solve the governing equations with the Boussinesq approximation. A code written in FORTRAN language developed to solve the governing equations in dimensionless forms using a finite volume approach with a SIMPLER algorithm. The results presented in U-velocity and V-velocity, isotherms, iso-concentration, streamline, the average Nusselt number, and the average Sherwood number for different values of the dimensionless parameters. A wide range of these parameters have been used including; Darcy Number, modified Rayleigh number, Lewis number, buoyancy ratio, and inclination angle.  The results show that for opposite buoyancy ratio (N≤-1), the Nu decreases when the Le increases and the Sh increase when the Le increases. For an (N>0), the Nu increases when the Le increases until Le is equal to 1 and then it decreases, also Sh increases when the Le increases

scholarly journals SIMILARITY SOLUTION OF HEAT AND MASS TRANSFER FOR LIQUID EVAPORATION ALONG A VERTICAL PLATE COVERED WITH A THIN POROUS LAYER

2021 ◽  
Vol 16 (4) ◽  
Author(s):  
Md Hasanuzzaman
Keyword(s):  
Mass Transfer ◽  
Differential Equations ◽  
Heat And Mass Transfer ◽  
Porous Layer ◽  
Vertical Plate ◽  
Nonlinear Partial Differential Equations ◽  
Lewis Number ◽  
Darcy Number ◽  
Shooting Technique ◽  
Liquid Evaporation

In this paper, heat and mass transfer for liquid evaporation along a vertical plate covered with a thin porous layer has been investigated. The continuity, momentum, energy and mass balance equations, which are coupled nonlinear partial differential equations are reduced to a set of two nonlinear ordinary differential equations and solved analytically and numerically by using the shooting technique in MATLAB. The effect of various parameters like the Froude number, the porosity, the Darcy number, the Prandtl number, the Lewis number and the driving parameters on the temperature and concentration profiles are presented and discussed. It is viewed that the heat transfer performance is enhanced by the presence of a porous layer. The local Nusselt number and the local Sherwood numbers are computed and analyzed both numerically and graphically.

scholarly journals Effect of Uniform and Non-Uniform Hot Wall Temperature on Species Separation in a Tilting Cell

2020 ◽  
Vol 307 ◽  
pp. 01035
Author(s):  
Mouna Touiker ◽  
Abdeslam Omara
Keyword(s):  
Aspect Ratio ◽  
Stokes Equations ◽  
Liquid Mixture ◽  
Lewis Number ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Left Wall ◽  
Tilting Angle ◽  
The Right ◽  
Volume Method

This work deals with the Soret separation of a binary liquid mixture (Water 60 wt %-Ethanol 40 wt %). The studied configuration is a tilted rectangular cavity of large aspect ratio A. It is assumed that the right wall is heated uniformly or non-uniformly, while the left wall is maintained at a constant cold temperature. The top and bottom walls are well insulated. A developed program (based on the finite-volume method and the semi-implicit method for pressure-linked equations algorithm) was utilized to numerically solve the governing Navier–Stokes equations, the energy and the species equations with the associated boundary conditions. The relevant parameters in this study are the tilting angle (α), the aspect ratio (A), the mass Rayleigh number (Ram) and the Lewis number (Le).

scholarly journals Hydrodynamic Mixed Convection in a Lid- Driven Porous Square Cavity with Internal Heat Generating Elliptic Block

2018 ◽  
Vol 37 ◽  
pp. 175-183 ◽  
Author(s):  
Abdul Halim Bhuiyan ◽  
M Jahirul Haque Munshi
Keyword(s):  
Mixed Convection ◽  
Internal Heat ◽  
Darcy Number ◽  
Constant Speed ◽  
Working Fluid ◽  
Square Cavity ◽  
Left Wall ◽  
Thermal Fields ◽  
Nusselt Numbers ◽  
The Right

Hydrodynamic mixed convection in a lid-driven porous square cavity with internal heat generating elliptic block is numerically simulated in this paper by employing finite element method. The working fluid is assigned as air with a Prandtl number of 0.71 throughout the simulation. The top lid moves left to right at a constant speed (U0)with cold temperature and while the bottom lid moves right to left at a constant speed (−U0) with hot temperature. The left wall is heated while the right wall is linearly heated and heat generating elliptic block is placed at the center of square cavity. The effects of governing parameters in the present study are namely, Rayleigh number Ra, Darcy number Da, Grash of number Gr. The effects of heat generation and the porosity of the medium on the streamlines, isotherms, temperature profiles, velocity field and average Nusselt numbers are presented in graphical and tabular forms and discussed. An optimum combination of the governing parameters would result in higher heat transfer. Moreover, it is observed that both the Darcy number and moving lid ordination have significant effects on the flow and thermal fields in the enclosure.GANIT J. Bangladesh Math. Soc.Vol. 37 (2017) 175-183

Combined Heat and Mass Transfer by Natural Convection in a Vertical Enclosure

1987 ◽  
Vol 109 (1) ◽  
pp. 104-112 ◽  
Author(s):  
O. V. Trevisan ◽  
A. Bejan
Keyword(s):  
Mass Transfer ◽  
Natural Convection ◽  
Heat And Mass Transfer ◽  
Lewis Number ◽  
Convective Mass Transfer ◽  
Transfer Rates ◽  
Rectangular Slot ◽  
Transfer Path ◽  
Mass Fluxes ◽  
Buoyancy Ratio

The phenomenon of natural convection caused by combined temperature and concentration buoyancy effects is studied analytically and numerically in a rectangular slot with uniform heat and mass fluxes along the vertical sides. The analytical part is devoted to the boundary layer regime where the heat and mass transfer rates are ruled by convection. An Oseen-linearized solution is reported for tall spaces filled with mixtures characterized by Le = 1 and arbitrary buoyancy ratios. The effect of varying the Lewis number is documented by a similarity solution valid for Le >1 in heat-transfer-driven flows, and for Le <1 in mass-transfer-driven flows. The analytical results are validated by numerical experiments conducted in the range 1≤H/L≤4, 3.5×105≤Ra≤7×106, −11≤n≤9, 1≤Le≤40, and Pr=0.7, 7. “Massline” patterns are used to visualize the convective mass transfer path and the flow reversal observed when the buoyancy ratio n passes through the value −1.

Investigating Double Diffusive Convection in an Inclined Rectangular Porous Enclosure Subjected to Magnetic Field

2009 ◽  
Author(s):  
Behnam Moghadassian ◽  
Pooyan Razi ◽  
Hossein Shokouhmand
Keyword(s):  
Magnetic Field ◽  
Mass Transfer ◽  
Flow Characteristics ◽  
Darcy Number ◽  
Double Diffusive Convection ◽  
Diffusive Convection ◽  
Dimensional Parameters ◽  
The Magnetic Field ◽  
Buoyancy Ratio ◽  
Double Diffusive

The problem of double diffusive convection in an inclined rectangular enclosure filled with a uniform porous medium at the presence of magnetic field has been studied. The constant temperature and concentration are imposed along two opposing walls, while the other two walls are adiabatic and impermeable to mass transfer. Non-dimensional governing equations are solved using the finite difference method. The representative results illustrates streamline, temperature, concentration and density contours as well as non-dimensional parameters of heat and mass transfer versus changes in magnitude and direction of magnetic field, buoyancy ratio, Darcy number and inclination angle of the enclosure. One of the main results is that average Nusselt and Sherwood numbers and flow characteristics depend significantly on the buoyancy ratio, Darcy number and direction of the magnetic field. Also it is observed that there is a decreasing trend in the average Nusselt and Sherwood numbers with increasing strength of the magnetic field.

Modified Lewis Number and Buoyancy Ratio Effects on Turbulent Double-Diffusive Convection in Porous Media Using the Thermal Nonequilibrium Model

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Marcelo J. S. de Lemos ◽  
Paulo H. S. Carvalho
Keyword(s):  
Thermal Conductivity ◽  
Porous Media ◽  
Nusselt Number ◽  
Average Nusselt Number ◽  
Lewis Number ◽  
Thermal Conductivity Ratio ◽  
Conductivity Ratio ◽  
Thermal Nonequilibrium ◽  
Buoyancy Ratio ◽  
Double Diffusive

This work presents a study of double-diffusive free convection in a porous square cavity under turbulent flow regime and with aiding drive. The thermal nonequilibrium model was employed to analyze the energy and mass transport across the enclosure. Governing equations were time- and volume-averaged according to the double-decomposition concept. Analysis of a modified Lewis number, Lem, showed that for porous media, this parameter presents opposite behavior when varying the thermal conductivity ratio or the Schmidt number, while maintaining the same value for Lem. Differently form free flow, the existence of the porous matrix contributes to the overall thermal diffusivity of the medium, whereas mass diffusivity is only effective within the fluid phase for an inert medium. Results indicated that increasing Lem through an increase in Sc reduces flow circulation inside porous cavities, reducing Nuw and increasing Shw. Results further indicate that increasing the buoyancy ratio N promotes circulation within the porous cavity, leading to an increase in turbulence levels within the boundary layers. Partial contributions of each phase of the porous cavity (solid and fluid) to the overall average Nusselt number become independent of n for higher values of the thermal conductivity ratio, ks/kf. Further, for high values of ks/kf, the average Nusselt number drops as N increases.

Our Bodies, Whose Property?

2013 ◽  
Author(s):  
Anne Phillips
Keyword(s):  
Labor Markets ◽  
Personal Autonomy ◽  
The Body ◽  
Body Parts ◽  
Complex Issue ◽  
Human Organs ◽  
Property Owners ◽  
The Common ◽  
The Difference ◽  
The Right

No one wants to be treated like an object, regarded as an item of property, or put up for sale. Yet many people frame personal autonomy in terms of self-ownership, representing themselves as property owners with the right to do as they wish with their bodies. Others do not use the language of property, but are similarly insistent on the rights of free individuals to decide for themselves whether to engage in commercial transactions for sex, reproduction, or organ sales. Drawing on analyses of rape, surrogacy, and markets in human organs, this book challenges notions of freedom based on ownership of our bodies and argues against the normalization of markets in bodily services and parts. The book explores the risks associated with metaphors of property and the reasons why the commodification of the body remains problematic. The book asks what is wrong with thinking of oneself as the owner of one's body? What is wrong with making our bodies available for rent or sale? What, if anything, is the difference between markets in sex, reproduction, or human body parts, and the other markets we commonly applaud? The book contends that body markets occupy the outer edges of a continuum that is, in some way, a feature of all labor markets. But it also emphasizes that we all have bodies, and considers the implications of this otherwise banal fact for equality. Bodies remind us of shared vulnerability, alerting us to the common experience of living as embodied beings in the same world. Examining the complex issue of body exceptionalism, the book demonstrates that treating the body as property makes human equality harder to comprehend.

ANALISIS YURIDIS NORMATIF PUTUSAN PERKARA MAHKAMAH AGUNG KONSTITUSI RI No. 004/PUU-II/2004

2013 ◽  
Vol 7 (1) ◽  
pp. 7
Author(s):  
Doni Budiono
Keyword(s):  
The Body ◽  
Supreme Courts ◽  
Military Justice ◽  
State Administration ◽  
The Supreme Court ◽  
Directorate General ◽  
The Government ◽  
Government Rules ◽  
The Right ◽  
Tax Court

The  authority  of justice in Indonesia  is executed by  the Supreme Courts and  the  justice  boards/body under the Supreme Courts, including  the general  justice, religious affairs justice, military justice,  state administration  justice,  and  the Constitution Court. According to  certainty in  the Act of  Tax Court, Article1, clause  (5),  tax  dispute   refers to the legal dispute arising in the  taxation  affairs between the  tax payer or the  body  responsible for the  tax with   the government   executives  ( Directorate General of Tax) as the consequence of   the issue of  the decree for the  appeal  to the Tax  Court in accordance with the  tax Act, including the  charge  against the  execution of collection   in accordance with the  Act of Tax Collection by force. The  formation of Tax Court is  designed by  the Executives, in this case, the  Department of Finance, specifically  the Directorate   General  of Tax  which has the right to issue  law  more technical about  tax accord to Article 14,  letter A,  President Decree  no. 44  year 1974,  concerning the  basic  organization of the Department.  Based on  it,  it  is clear that  in addition to execute the government  rules and policy,  this body  has to execute judicial   rules and policy. This is against the  principles of  Judicative  Power/Authority in Indonesia,  which   clearly states that this body  should be under the Supreme Court.   Therefore. It is suggested that   the Act  No UU no.14 Year 2012 concerning  Tax Court   be revised  in accordance with the system of  Power Division  of Justice  as  stated in 45 Constitutions.

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