Effect of Inter-Connector on Thermo-Hydraulic Characteristics of Parallel and Counter Flow Mini-Channel Heat Sink

2018 ◽  
Author(s):  
Amitav Tikadar ◽  
Saad K. Oudah ◽  
Azzam S. Salman ◽  
A. K. M. M. Morshed ◽  
Titan C. Paul ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Sink ◽  
Conjugate Heat Transfer ◽  
Single Phase ◽  
Three Dimensional ◽  
Cross Flow ◽  
Constant Heat Flux ◽  
Hydraulic Characteristics ◽  
Counter Flow ◽  
Flow And Heat Transfer

A numerical investigation of three-dimensional conjugate heat transfer was performed to quantify the thermal and hydraulic performance of an inter-connected parallel and counter flow mini-channel heat sink under laminar flow condition and within the single-phase regime. The aspect ratio (height/width) and the hydraulic diameter of the mini-channel were 0.33 and 750μm respectively. Three different widths of the inter-connector were selected to analyze the effect of cross flow for Reynolds number ranging from 150 to 1044, at a constant heat flux (20 W/cm2). To understand the fluid flow and heat transfer mechanism inside the inter-connector and their effects on overall thermal performance of the heat sink, Nusselt number (Nu), friction factor, pumping power, and overall thermal resistance were analyzed. Results show that the inter-connector has significantly higher effect on counter flow mini-channel heat sink than parallel flow mini-channel heat sink.

Numerical Analysis of Blockage and Optimization of Heat Transfer Performance of Fractal-like Microchannel Nets

2005 ◽  
Vol 128 (1) ◽  
pp. 38-45 ◽  
Author(s):  
Xiang-Qi Wang ◽  
Arun S. Mujumdar ◽  
Christopher Yap
Keyword(s):  
Heat Transfer ◽  
Heat Sink ◽  
Flow Resistance ◽  
Heat Transfer Performance ◽  
Three Dimensional ◽  
Constant Heat Flux ◽  
Low Flow ◽  
Flow And Heat Transfer ◽  
Computational Fluid Dynamics Cfd ◽  
Number Of Branches

The conjugate fluid flow and heat transfer characteristics of fractal-like microchannel nets embedded in a disk-shape heat sink are investigated using a three-dimensional computational fluid dynamics (CFD) approach. A constant heat flux is applied to the top wall of the heat sink. The intrinsic advantages of fractal-like microchannel nets such as low flow resistance, temperature uniformity, and reduced danger of blockage compared with the traditional parallel channel nets are demonstrated. In addition, various optimized designs with parameters such as the number of branches, number of branching levels, and number of channels that reach the center of the disk are addressed in this context.

scholarly journals The Effect of Geometrical Parameters on Heat Transfer Characteristics of Compact Heat Exchanger with Louvered Fins

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
P. Gunnasegaran ◽  
N. H. Shuaib ◽  
M. F. Abdul Jalal
Keyword(s):  
Heat Transfer ◽  
Heat Exchangers ◽  
Three Dimensional ◽  
Cross Flow ◽  
Geometrical Parameters ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Flow And Heat Transfer ◽  
Drop Flow ◽  
Louvered Fins

Compact heat exchangers (CHEs) have been widely used in various applications in thermal fluid systems including automotive thermal management systems. Among the different types of heat exchangers for engine cooling applications, cross-flow CHEs with louvered fins are of special interest because of their higher heat rejection capability with the lower flow resistance. In this study, the effects of geometrical parameters such as louver angle and fin pitch on air flow and heat transfer characteristics on CHEs are numerically investigated. Numerical investigations using five different cases with increased and decreased louver angles (+2°, +4°, −2°, −4°, and uniform angle 20°), with a fixed fin pitch and using three different fin pitches (1.0 mm, 2.0 mm, and 4.0 mm), and with the fixed louver angle are examined. The three-dimensional (3D) governing equations for the fluid flow and heat transfer are solved using a standard finite-volume method (FVM) for the range of Reynolds number between 100 and 1000. The computational model is used to study the variations of pressure drop, flow temperature, and Nusselt number.

Direct Numerical Simulation of Flow and Heat Transfer From a Sphere in a Uniform Cross-Flow

2000 ◽  
Vol 123 (2) ◽  
pp. 347-358 ◽  
Author(s):  
P. Bagchi ◽  
M. Y. Ha ◽  
S. Balachandar
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Nusselt Number ◽  
Vortex Shedding ◽  
Axisymmetric Flow ◽  
Three Dimensional ◽  
Cross Flow ◽  
Reynolds Numbers ◽  
Temperature Fields ◽  
Flow And Heat Transfer

Direct numerical solution for flow and heat transfer past a sphere in a uniform flow is obtained using an accurate and efficient Fourier-Chebyshev spectral collocation method for Reynolds numbers up to 500. We investigate the flow and temperature fields over a range of Reynolds numbers, showing steady and axisymmetric flow when the Reynolds number is less than 210, steady and nonaxisymmetric flow without vortex shedding when the Reynolds number is between 210 and 270, and unsteady three-dimensional flow with vortex shedding when the Reynolds number is above 270. Results from three-dimensional simulation are compared with the corresponding axisymmetric simulations for Re>210 in order to see the effect of unsteadiness and three-dimensionality on heat transfer past a sphere. The local Nusselt number distribution obtained from the 3D simulation shows big differences in the wake region compared with axisymmetric one, when there exists strong vortex shedding in the wake. But the differences in surface-average Nusselt number between axisymmetric and three-dimensional simulations are small owing to the smaller surface area associated with the base region. The shedding process is observed to be dominantly one-sided and as a result axisymmetry of the surface heat transfer is broken even after a time-average. The one-sided shedding also results in a time-averaged mean lift force on the sphere.

Analysis of Conjugate Heat Transfer in a Three-Dimensional Microchannel Heat Sink for Cooling of Electronic Components

1999 ◽  
Author(s):  
Andrei G. Fedorov ◽  
Raymond Viskanta
Keyword(s):  
Heat Transfer ◽  
Heat Sink ◽  
Conjugate Heat Transfer ◽  
Stokes Equations ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Solid Substrate ◽  
Microchannel Heat Sink ◽  
Three Dimensional Model ◽  
Wide Range

Abstract A three-dimensional model is developed to investigate flow and conjugate heat transfer in the microchannel-based heat sink for electronic packaging applications. The incompressible laminar flow Navier-Stokes equations of motion as well as the energy conservation equations for the fluid and solid are employed as the governing model equations which are numerically solved using the generalized single-equation framework for solving conjugate problems. First, the theoretical model developed is validated by comparing the model predictions of the thermal resistance and the friction coefficient with available experimental data for a wide range of Reynolds numbers. Then, the parametric calculations are performed to investigate the effects of different working fluids, solid substrate materials and channel geometry on conjugate heat transfer in the microchannel heat sink. The bulk and wall temperature and heat flux distributions as well as the average heat transfer characteristics are reported and discussed. Important practical design recommendations are also provided regarding the cooling efficiency of the microchannel heat sink.

Experimental Study of Forced Convection Heat Transfer and Flow Friction of a Water-Cooled Inter-Connected Mini-Channel Heat Sink

2019 ◽  
Author(s):  
Amitav Tikadar ◽  
Saad K. Oudah ◽  
Nabeel M. Abdulrazzaq ◽  
Titan C. Paul ◽  
Jamil A. Khan
Keyword(s):  
Heat Transfer ◽  
Friction Factor ◽  
Heat Sink ◽  
Convection Heat Transfer ◽  
Constant Heat Flux ◽  
Transverse Flow ◽  
Working Fluid ◽  
Experimental Investigations ◽  
Bottom Surface ◽  
Counter Flow

Abstract Experimental investigations were performed to quantify the thermal and hydraulic performances of an inter-connected counter flow mini-channel heat sink under laminar flow regime. The aspect ratio (height/width) and the hydraulic diameter of the mini-channel were 0.33 and 750 μm respectively. Water was used as the working fluid, and a constant heat flux of 120000 W/m2 was applied on the bottom surface of the heat sink. To enable transverse flow between two counter flow streams by utilizing pressure difference, two inter-connectors were made on the middle wall. The height and width of both inter-connectors were the same as the mini-channel. Bottom surface temperature, Nusselt number (Nu), thermal resistance, and friction factor were calculated to address the effect of the inter-connectors on the overall thermal-hydraulic performance of the heat sink. The results showed that at low Reynolds number (Re), inter-connectors affect the heat transfer performance adversely while substantial heat transfer augmentation was achieved at high Re. Additionally, for all of the test range, a significant reduction of friction factor was achieved by employing transverse flow.

Three-Dimensional Analysis of Fluid Flow and Heat Transfer in the Microchannel Heat Sink Using Additive-Correction Multigrid Technique

2008 ◽  
Author(s):  
Omid Asgari ◽  
Mohammad Hassan Saidi
Keyword(s):  
Heat Transfer ◽  
Heat Sink ◽  
Large Scale ◽  
Three Dimensional ◽  
Equation System ◽  
Microchannel Heat Sink ◽  
Poisson Equations ◽  
Acceleration Technique ◽  
Flow And Heat Transfer ◽  
Additive Correction

Heat generation from very large-scale integrated (VLSI) circuits increases with the advent of high-density integrated circuit technology. One of the promising techniques is liquid cooling by using microchannel heat sink. Numerical works on the microchannel heat sink in the literature are mostly two dimensional. The purpose of the present study is to develop a three-dimensional analysis procedure to investigate flow and conjugate heat transfer in the microchannel-based heat sink for electronic packaging applications. The micro-heat sink model consists of a 10 mm long silicon substrate, with rectangular microchannels, 57 μm wide and 180 μm deep, fabricated along the entire length. A finite volume numerical code with a multigrid technique, based on additive correction multigrid (AC-MG) scheme, that is a high-performance solver, was developed to solve the steady incompressible laminar Navier–Stokes (N–S) equations, over a colocated Cartesian grid arrangement. The results indicate that thermophysical properties of the liquid can significantly influence both the flow and heat transfer in the microchannel heat sink. Comparison of the numerical results with other published numerical results and experimental data available in the literature for Reynolds numbers less than 200 based on a hydraulic diameter of Dh = 86 μm and Dh/Lx<0.01, indicates that the assumption of hydrodynanmic, fully developed laminar flow is valid. The current research indicates that the AC-MG acceleration technique is highly efficient, reliable and robust, which makes it feasible for CPU-intensive computations, such as pressure Poisson equations. When compared to the discretized momentum equations, the pressure Poisson equations tend to be very stiff and ill-conditioned, i.e ap ≡ Σnb anb Because of these reasons, solving the pressure Poisson equation is usually the CPU bottle-neck for the incompressible N–S equation system and AC-MG technique is required. With this acceleration technique the residuals of the large-scale algebraic equation system are guaranteed to be continuously driven down to the level of the computer machine round-off error and warrants strong conservations of mass and momentum satisfied over all the control volumes. In this cell centered multigrid algorithm both restriction and prolongation operators are based on piecewise constant interpolation. The accuracy of the prediction has been verified by comparing the results obtained with the numerical and analytical results from the open literature.

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.

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