scholarly journals Numerical Study of Air-Flow Phenomena Through a Baffled Rectangular Micro-Channel

2021 ◽  
Vol 13 (2) ◽  
pp. 51-57
Author(s):  
Sandip Saha
Keyword(s):  
Heat Transfer ◽  
Numerical Study ◽  
Micro Channel ◽  
Flow And Heat Transfer ◽  
Flow Phenomena ◽  
Turbulent Airflow ◽  
Fluent Software ◽  
Volume Method

The aim of this study is to investigate the heat transfer characteristics of turbulent airflow phenomena in a rectangular micro-channel in presence of two plane shaped (type-1) and diamond shaped (type-2) baffles which will help to develop various heat exchanger models. Finite volume method has been used to solve the governing equations and the FLUENT software has been employed to visualize the simulation results. For both the baffles, the profile of flow structure, normalized velocity profile, normalized friction factor and average Nusselt number have been investigated with the variations of Reynolds number ranges between [10,000-50,000]. In terms of fluid flow and heat transfer phenomena, it has been found that in the presence of diamond shaped baffles (type-2) are more convenient than plane shaped baffles.

scholarly journals Lid-Driven and Inclined Square Cavity Filled With a Nanofluid: Optimum Heat Transfer

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Abdelkader Boutra ◽  
Karim Ragui ◽  
Nabila Labsi ◽  
Youb Khaled Benkahla
Keyword(s):  
Heat Transfer ◽  
Volume Fraction ◽  
Numerical Study ◽  
Square Enclosure ◽  
Coupled Equations ◽  
Flow And Heat Transfer ◽  
Wide Range ◽  
Optimum Heat ◽  
Nanoparticles Volume Fraction ◽  
Volume Method

AbstractThis paper reports a numerical study on mixed convection within a square enclosure, filled with a mixture of water and Cu (or Ag) nanoparticles. It is assumed that the temperature difference driving the convection comes from the side moving walls, when both horizontal walls are kept insulated. In order to solve the general coupled equations, a code based on the finite volume method is used and it has been validated after comparison between the present results and those of the literature. To make clear the effect of the main parameters on fluid flow and heat transfer inside the enclosure, a wide range of the Richardson number, taken from 0.01 to 100, the nanoparticles volume fraction (0% to 10%), and the cavity inclination angle (0º to 180º) are investigated. The phenomenon is analyzed through streamlines and isotherm plots, with special attention to the Nusselt number.

Heat Transfer Improvement in a Square Duct with Diagonal Inclined Ribs

2014 ◽  
Vol 931-932 ◽  
pp. 1144-1148
Author(s):  
Supattarachai Suwannapan ◽  
Ratsak Poomsalood ◽  
Pongjet Promvonge ◽  
Withada Jedsadaratanachai ◽  
Thitipat Limkul
Keyword(s):  
Heat Transfer ◽  
Friction Factor ◽  
Numerical Study ◽  
Simple Algorithm ◽  
Reynolds Numbers ◽  
Square Duct ◽  
Flow And Heat Transfer ◽  
Pitch Ratio ◽  
Volume Method ◽  
Heat Transfer Improvement

This research presents a numerical study of turbulent periodic flow and heat transfer in threedimensional isothermalfluxed square duct with diagonal inclined rib inserted. The fluid flow and heat transfer characteristics are presented for Reynolds numbers in the range of 4000 to 20,000. The computations based on the finite volume method, and the SIMPLE algorithm has been implemented. Effects of rib pitch ratios (0.5 to 2) at a single blockage ratio of 0.2 and attack angle of 60o on heat transfer and friction factor in the duct are examined and their results of the inclined rib are also compared with those of the smooth duct. It is found that the inclined rib provides higher heat transfer rate and friction factor than the smooth duct for all cases. In addition, the decreasing of the pitch ratio leads to the rise in the Nusselt number and friction factor.

scholarly journals Numerical study of melting in an annulur enclosure filled with nano-enhanced phase change material

2015 ◽  
Vol 19 (3) ◽  
pp. 1067-1076 ◽  
Author(s):  
Seyed Sebti ◽  
Mohammad Mastiani ◽  
Sina Kashani ◽  
Hooshyar Mirzaei ◽  
Ahmad Sohrabi
Keyword(s):  
Heat Transfer ◽  
Volume Fraction ◽  
Numerical Study ◽  
Melting Time ◽  
Nanoparticle Dispersion ◽  
Flow And Heat Transfer ◽  
Cylindrical Annulus ◽  
Pure Fluid ◽  
Volume Method ◽  
Change Material

Heat transfer enhancement during melting in a two-dimensional cylindrical annulus through dispersion of nanoparticle is investigated numerically. Paraffin-based nanofluid containing various volume fractions of Cu is applied. The governing equations are solved on a non-uniform O type mesh using a pressure-based finite volume method with an enthalpy porosity technique to trace the solid and liquid interface. The effects of nanoparticle dispersion into pure fluid as well as the influences of some significant parameters, namely, nanoparticle volume fraction and natural convection on the fluid flow and heat transfer features are studied. The results are presented in terms of streamlines, isotherms, temperatures and velocity profiles and dimensionless heat flux. It is found that the suspended nanoparticles give rise to the higher thermal conductivity as compared to the pure fluid and consequently the heat transfer is enhanced. In addition, the heat transfer rate and the melting time increases and decreases, respectively, as the volume fraction of nanoparticle increases.

scholarly journals Numerical study on characteristics of flow and thermal fields around rotating cylinder

10.30544/450 ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 71-86
Author(s):  
Kamel Korib ◽  
Mohamed ROUDANE ◽  
Yacine Khelili
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Numerical Study ◽  
Simple Algorithm ◽  
Rotation Rates ◽  
Rotating Circular Cylinder ◽  
Flow And Heat Transfer ◽  
Lift And Drag ◽  
Energy Equations ◽  
Volume Method

In this paper, a numerical simulation has been performed to study the fluid flow and heat transfer around a rotating circular cylinder over low Reynolds numbers. Here, the Reynolds number is 200, and the values of rotation rates (α) are varied within the range of 0 < α < 6. Two-dimensional and unsteady mass continuity, momentum, and energy equations have been discretized using the finite volume method. SIMPLE algorithm has been applied for solving the pressure linked equations. The effect of rotation rates (α) on fluid flow and heat transfer were investigated numerically. Also, time-averaged (lift and drag coefficients and Nusselt number) results were obtained and compared with the literature data. A good agreement was obtained for both the local and averaged values.

Numerical Study of Natural Convection in a Differentially-Heated Rectangular Cavity Filled with TiO2-Water Nanofluid

2011 ◽  
Vol 13 ◽  
pp. 75-80 ◽  
Author(s):  
Ghanbar Ali Sheikhzadeh ◽  
A. Arefmanesh ◽  
Mostafa Mahmoodi
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Volume Fraction ◽  
Numerical Study ◽  
Rectangular Cavity ◽  
Flow And Heat Transfer ◽  
Shallow Cavities ◽  
The Mean ◽  
Volume Method ◽  
Rayleigh Numbers

In this study, the buoyancy-driven fluid flow and heat transfer in a differentially-heated rectangular cavity filled with the TiO2-water nanofluid is investigated numerically. The left and the top walls of the cavity are maintained at constant temperatures Thand Tc, respectively, with Th> Tc.The enclosure’s right and bottom walls are kept insulated. The governing equations are discretized using the finite volume method. A proper upwinding scheme is employed to obtain stabilized solutions for high Rayleigh numbers. Using the developed code, a parametric study is undertaken, and the effects of pertinent parameters, such as, the Rayleigh number, the aspect ratio of the cavity and the volume fraction of the nanoparticles on the fluid flow and heat transfer inside the cavity are investigated. It is observed from the results that by increasing the volume fraction of the nanoparticles, the mean Nusselt number of the hot wall increases for the shallow cavities; while, the reverse trend occurs for the tall cavities. Moreover, the heat transfer enhancement utilizing nanofluid is more effective at Ra = 103.

Three-Dimensional Analysis of Fluid Flow and Heat Transfer in Single- and Two-Layered Micro-Channel Heat Sinks

2008 ◽  
Author(s):  
M. L.-J. Levac ◽  
H. M. Soliman ◽  
S. J. Ormiston
Keyword(s):  
Heat Transfer ◽  
Heat Sink ◽  
Numerical Study ◽  
Three Dimensional ◽  
Heat Sinks ◽  
Micro Channel ◽  
Flow Conditions ◽  
Flow And Heat Transfer ◽  
Computer Chips ◽  
Laminar Flow Conditions

Micro-channel heat sinks are currently at the forefront of cooling technologies for computer chips where the input heat flux is projected to exceed 100 W/cm2 [1, 2]. The quest for better heat-sink designs has produced different ideas, one of which is the idea of using multi-layered micro-channel heat sinks [3, 4]. The objectives of the present investigation were to conduct a detailed numerical study of the hydrodynamic and thermal behavior of a two-layered micro-channel heat sink and to compare the performance of the two-layered heat sink with that of a single-layered sink under laminar flow conditions.

Flow and Heat Transfer of the Cu-Water Nanofluid in a Corrugated Channel

2021 ◽  
Vol 8 (9) ◽  
pp. 507-517
Author(s):  
Rahima Benchabi ◽  
Ahsene Lanani
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Numerical Simulations ◽  
Metallic Nanoparticles ◽  
Volume Fraction ◽  
Corrugated Channel ◽  
Flow And Heat Transfer ◽  
Fluent Software ◽  
Volume Method ◽  
Good Agreement

This paper is devoted to study the influence of the Cu-water nanofluid on a two-dimensional laminar and incompressible flow and heat transfer in a corrugated triangular-based channel filled with homogeneous mixture of water and metallic nanoparticles. The equations governing the problem were solved using the finite volume method. ANSYS 15.0 FLUENT software was used to perform the numerical simulations. These numerical simulations were carried out for different values of the Reynolds number ranging from 100 to 1000 and for metallic nanoparticles of diameter with volume fractions of and. The effect of the Reynolds number, the nature of the nanofluid on the flow field and the heat transfer were studied. Note that the obtained results are in good agreement with the results existing in the literature. Keywords: Cu-water nanofluid, Fluent, forced convection, Reynolds number, volume fraction.

Three-Dimensional Flow and Heat Transfer Calculations in Micro-Channel Heat Exchangers

2001 ◽  
Author(s):  
A. K. Saha ◽  
Sumanta Acharya
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Friction Factor ◽  
Critical Reynolds Number ◽  
Numerical Study ◽  
Turbine Blades ◽  
Three Dimensional ◽  
Plane Channel ◽  
Micro Channel ◽  
Flow And Heat Transfer

Abstract A three-dimensional numerical study has been carried out to analyze the unsteady flow and heat transfer in a micro-channel with an array of periodically mounted square cylinders. The current geometry represents a micro-heat exchanger and has potential applications in the cooling of turbine blades and electronic cooling. The cylinder dimensions are of the order of few microns. The three-dimensional unsteady Navier-Stokes and energy equations are solved using higher order temporal and spatial discretizations. The simulations have been carried out for a range of Reynolds number based on cylinder width (180–600) and a Prandtl number of 6.99. Conjugate heat transfer calculations have been employed to account for the conduction in the solid cylinder and convection in the fluid. The flow is found to become unsteady at a critical Reynolds number that falls between 250 and 400. The flow shows quasi-periodic behavior with multiple frequencies at a Reynolds number of 400. The heat transfer enhancement compared to a plane channel is marginal (1.1–1.4 times) for the steady flow cases whereas it is significant (12–15 times) when the flow is unsteady. The friction factor was found to decrease with Reynolds number in both the steady and unsteady regimes. However, the friction factor increases at the critical Reynolds number where it becomes unsteady in nature.

scholarly journals Numerical Study of Laminar Forced Convection of Nanofluid in a New Microchannel Heat Sink

2021 ◽  
Vol 71 (2) ◽  
pp. 31-40
Author(s):  
Bouhabel Bourhane ◽  
Kabar Yassine
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Heat Sink ◽  
Numerical Study ◽  
Microchannel Heat Sink ◽  
Ansys Fluent ◽  
Mixing Chamber ◽  
Fluent Software ◽  
Volume Method ◽  
Laminar Forced Convection

Abstract The heat transfer and pressure drop in a microchannel heat sink with 02 mixing chambers with inclined walls were numerically studied. The transport equations have been resolved by the finite volume method using ANSYS Fluent software. The operating fluids are water and Al2O3-water. The results obtained for Reynolds numbers ranging from 187 and 705 show that adding a micro-mixing chamber with a rectangular rib in the microchannel improves the heat transfer and increases the pressure drop compared to conventional microchannels. The new shape of the mixing chamber studied shows a net decrease in pressure drop, which improves the performance of the micro heat sink by 5.6%.

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