On Suddenly Expanding Non-Isothermal Pipe Flows of a Bingham Fluid

1999 ◽  
Author(s):  
Khaled J. Hammad
Keyword(s):  
Heat Transfer ◽  
Newtonian Fluid ◽  
Transfer Problem ◽  
Numerical Technique ◽  
Complex Nature ◽  
Brinkman Number ◽  
Governing Equations ◽  
Heat Transfer Characteristics ◽  
Flow And Heat Transfer ◽  
Pipe Expansion

Abstract The non-isothermal laminar flow of the Bingham non-Newtonian fluid through a sudden pipe expansion is investigated. The governing equations of conservation of mass, momentum and energy are solved using the finite-difference numerical technique. The effects of non-dimensional yield stress, Reynolds number, Prandtl number and Brinkman number on the flow and heat transfer characteristics are studied. The obtained results indicate the complex nature of the present non-Newtonian fluid flow and heat transfer problem and reveal new features not encountered in the case of Newtonian fluids.

Numerical Simulation of an ADSS With Surface Heat Flux and Heat Generation Using FEM

2005 ◽  
Author(s):  
K. Arul Prakash ◽  
G. Biswas ◽  
B. V. Rathish Kumar
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Generation ◽  
Nuclear Reactors ◽  
Critical Conditions ◽  
Governing Equations ◽  
Heat Transfer Characteristics ◽  
Critical System ◽  
Flow And Heat Transfer ◽  
Interest In Research

ADSS (Accelerator Driven Sub-critical System) nuclear reactors have evoked renewed interest in research because it operates in sub-critical conditions and transmutes nuclear wastes. Numerical investigation of fluid flow and heat transfer characteristics of an ADSS has been accomplished using a finite element method based on Streamline Upwind Petrov-Galerkin (SUPG) technique. The time-dependent governing equations for conservation of mass, momentum and energy are solved. The simulations have been carried out to predict the heat transfer in the spallation regime. The cases of beam window with heat flux prescription is analyzed in the absence and presence of heat generation in the liquid metal. At the first place, laminar regime of the flow is considered for the ADSS geometry. The Reynolds number of interest were varied over a specified range.

Magnetohydrodynamics Flow and Heat Transfer Around a Solid Cylinder Wrapped With a Porous Ring

2014 ◽  
Vol 136 (6) ◽  
Author(s):  
Mohammad Sadegh Valipour ◽  
Saman Rashidi ◽  
Reza Masoodi
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Nusselt Number ◽  
Critical Radius ◽  
Governing Equations ◽  
Heat Transfer Characteristics ◽  
Electrically Conductive ◽  
Flow And Heat Transfer ◽  
Volume Method ◽  
Physical Phenomena

The problem of the effect of an external magnetic field on fluid flow and heat transfer characteristics is relevant to several physical phenomena. In this paper, flow and heat transfer of an electrically-conductive fluid around a cylinder, wrapped with a porous ring and under the influence of a magnetic field, is studied numerically. The ranges of the Stuart (N), Reynolds (Re), and Darcy (Da) numbers are 0–7, 1–40, and 10−8–10−1, respectively. The Darcy–Brinkman–Forchheimer model was used for simulating flow in the porous layer. The governing equations provide a coupling between flow and magnetic fields. The governing equations, together with the relevant boundary conditions, are solved numerically using the finite-volume method (FVM). The effect of the Stuart, Reynolds, and Darcy numbers on the flow patterns and heat transfer rate are explored. Finally, two empirical equations for the average Nusselt number were suggested, in which the effect of a magnetic field and the Darcy numbers are taken into account. It was found that in the presence of a magnetic field, the drag coefficient and the critical radius of the insulation increases, while the wake length and Nusselt number decrease.

Numerical Simulation on Flow and Heat Transfer of Power Law Fluid in Structured Packed Porous Media of Particles

2017 ◽  
Vol 865 ◽  
pp. 239-246
Author(s):  
Xing Wang Tian ◽  
Yu Zhen Yin ◽  
Ping Wang ◽  
Lin Xu
Keyword(s):  
Heat Transfer ◽  
Porous Media ◽  
Newtonian Fluid ◽  
Power Law ◽  
Three Dimensional ◽  
Particle Diameter ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Flow And Heat Transfer ◽  
Power Law Index

Flow and heat transfer of non-Newtonian fluid in porous media is an universal physical process in nature, industry and agriculture. With a certain concentration of HPAM aqueous solution (a typical power-law type non-Newtonian fluid) as the fluid medium, constructing the porous media skeleton model of orderly arrangement of spherical particles, the flow and heat transfer characteristics in three-dimensional orderly arrangement of porous media have been investigated numerically by using Fluent software. By employing the method of fluid-solid coupling subject to uniform heat flux, the effects of power law fluid rheological index, particle material, particle diameter and porosity on the flow and heat transfer characteristics are analyzed in detail. And also the concept of thermal efficiency is introduced to gain the comprehensive evaluation of its flow and heat transfer characteristics. The results show that the flow resistance decreases with the increase of the power-law index, particle diameter and porosity, and has nothing to do with the thermal conductivity coefficient of particles; while the local convection heat transfer coefficient increases with the increase of the power-law index and the thermal conductivity coefficient of particles, and decreases with the increase of particle diameter and porosity. The results can provide a theoretical basis for the flow and heat transfer mechanism of the power-law type non-Newtonian fluid flowing through the three-dimensional structured packed porous media of particles.

scholarly journals Mixed magnetoconvection in a lid-driven cavity with a sinusoidal wavy wall and a central heat conducting body

2011 ◽  
Vol 8 (1) ◽  
pp. 13-24 ◽  
Author(s):  
Rehena Nasrin
Keyword(s):  
Heat Transfer ◽  
Numerical Study ◽  
Vertical Surface ◽  
Heat Conducting ◽  
Governing Equations ◽  
Heat Transfer Characteristics ◽  
Driven Cavity ◽  
Average Temperature ◽  
Transfer Characteristics ◽  
Flow And Heat Transfer

A numerical study has been performed to explore the mixed magnetoconvective flow and heat transfer characteristics of fluid contained in a lid-driven cavity having a sinusoidal wavy vertical surface. A heat conducting square body is located at the centre of cavity. The cavity horizontal walls are perfectly insulated while the corrugated right vertical surface is maintained at a uniform temperature higher than the left lid. The flow is assumed to be two-dimensional and Joule heating effect is considered. Calculations are carried out through solving governing equations for different parameters by using Galarkin’s weighted residual finite element method. The flow pattern and the heat transfer characteristics inside the cavity are presented in the form of streamlines, isotherms, average temperature of the fluid and temperature of solid body centre for various values of Prandtl number Pr, Richardson number Ri and magnetic parameter Ha. The heat transfer rate is detected maximum for the highest Pr and absence of magnetic field.DOI: http://dx.doi.org/10.3329/jname.v8i1.6793

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