scholarly journals Optimization of Fins Arrangements for the Square Light Edding Diode (LED) Cooling through Nanofluid-Filled Microchannel

2021 ◽  
Author(s):  
Mohamed Bechir Ben Hamida ◽  
Mohammad Hatami
Keyword(s):  
Heat Transfer ◽  
Convection Heat Transfer ◽  
Micro Channel ◽  
Cooling Fluid ◽  
Heat Transfer Efficiency ◽  
Surface Method ◽  
Die Attach ◽  
Flow Through ◽  
Central Composite ◽  
Fin Length

Abstract In current paper, a finned micro-channel is designed for the cooling application in Light Edding Diode (LED), numerically. Selected materials for LED-chip is GaN, Die from Si, Die-attach is made by Au-20Sn, substrate is copper and heat sink material is considered to be Al. To make a convection heat transfer for cooling process, Al2O3-water nanofluid is used as the cooling fluid flow through the micro-channel and tried to maximize the heat transfer efficiency by optimized geometry. For this aim, there geometry variables from the microchannel were selected and minimum possible geometry cases (11cases) were proposed by Central composite design (CCD) and variables were optimized by the Response Surface Method (RSM). As a main result, parameter B, i.e. fin length had the most effect on the Nusselt number and Al2O3 nanoparticles with φ = 0.01 stated greatest heat transfer value.

scholarly journals Optimization of fins arrangements for the square light emitting diode (LED) cooling through nanofluid-filled microchannel

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mohamed Bechir Ben Hamida ◽  
Mohammad Hatami
Keyword(s):  
Heat Transfer ◽  
Light Emitting Diode ◽  
Convection Heat Transfer ◽  
Micro Channel ◽  
Cooling Process ◽  
Cooling Fluid ◽  
Light Emitting ◽  
Heat Transfer Efficiency ◽  
Die Attach ◽  
Flow Through

AbstractIn current paper, a finned micro-channel is designed for the cooling application in Light Emitting Diode (LED), numerically using Galerkin weighted residual Finite Element Method (GFEM). Selected materials for LED-chip is GaN, Die from Si, Die-attach is made by Au-20Sn, substrate is copper and heat sink material is considered to be Al. To make a convection heat transfer for cooling process, Al2O3-water nanofluid is used as the cooling fluid flow through the micro-channel and tried to maximize the heat transfer efficiency by optimized geometry. For this aim, there geometry variables from the microchannel were selected and minimum possible geometry cases (11 cases) were proposed by Central composite design (CCD) and variables were optimized by the Response Surface Method (RSM). As a main result, parameter B, i.e. fin length had the most effect on the Nusselt number and Al2O3 nanoparticles with φ = 0.05 stated greatest heat transfer value. Also, different designs of fins arrangements, caused up to 6.5% increase in the nanofluid temperature which enhanced the LED cooling process.

Bio-Inspired Segmented Flow: Effect of Particle Elongation on the Heat Transfer

2013 ◽  
Vol 135 (7) ◽  
Author(s):  
Laura Small ◽  
Fatemeh Hassanipour
Keyword(s):  
Heat Transfer ◽  
Phase Change ◽  
Exchange Process ◽  
Convection Heat Transfer ◽  
Spherical Geometry ◽  
Spherical Particles ◽  
Channel Height ◽  
Segmented Flow ◽  
Heat Transfer Efficiency ◽  
Shaped Particle

This study presents numerical simulations of forced convection heat transfer with parachute-shaped segmented flow. The particles are encapsulated phase-change material flowing with water through a square cross-section duct with iso-flux boundaries. The system is inspired by the gas exchange process in the alveolar capillaries between red blood cells and lung tissue. A numerical model is developed for the motion of elongated encapsulated phase-change particles along a channel in a particulate flow where particle diameters are comparable with the channel height. The heat transfer enhancement for the parachute-shaped particles is compared with that of the spherical particles. Results reveal that the snug movement of the particles has the key role in heat transfer efficiency. The parachute-shaped geometry produces small changes in the heat transfer coefficient compared to a spherical geometry. However, the parachute-shaped particle flow is more robust to changes in particle concentration inside the channel.

Cavity Heat Transfer on a Transverse Grooved Wall in a Narrow Flow Channel

1989 ◽  
Vol 111 (1) ◽  
pp. 73-79 ◽  
Author(s):  
D. E. Metzger ◽  
R. S. Bunker ◽  
M. K. Chyu
Keyword(s):  
Heat Transfer ◽  
Experimental Situation ◽  
Turbine Blades ◽  
Convection Heat Transfer ◽  
Heat Transfer Characteristics ◽  
Cavity Depth ◽  
Intermediate Depth ◽  
Narrow Slot ◽  
Flow Through ◽  
Cavity Floor

Measurements are presented of local convection heat transfer for the case of flow through a narrow slot-type channel where one of the bounding walls contains a transverse rectangular cavity. The experimental situation is a stationary modeling of some salient features of flow through the clearance gap at the grooved tips of axial turbine blades. Cavity depth-to-width ratios of 0.1, 0.2, and 0.5 are included for each of clearance-to-width ratios of 0.05, 0.10, and 0.15. Overall heat transfer on the cavity floor is in general reduced as cavity depth is increased, but reduction with the deepest cavity tested is essentially the same as that of the intermediate depth cavity. Resistance to flow through the gap is increased as cavity depth is increased, but again the change between the deepest and intermediate depth cavities is small. In addition to the stationary experiments, heat transfer in the cavity with a moving as well as stationary shroud is modeled with a finite-difference method. The numerical results indicate that, within the range of parameters considered, heat transfer characteristics in the cavity are virtually unaffected by the shroud movement. This is in agreement with a previous finding for heat transfer on ungrooved blade tips.

Research on Trait in Heat Exchange and Flow of Inner Single-Phase Currentin Micro Channel

2012 ◽  
Vol 516-517 ◽  
pp. 408-413 ◽  
Author(s):  
Yue Lian Hu
Keyword(s):  
Heat Transfer ◽  
Heat Exchange ◽  
Single Phase ◽  
Fluid Dynamic ◽  
High Heat ◽  
Micro Channel ◽  
Heat Transfer Efficiency ◽  
Flow And Heat Transfer ◽  
High Heat Transfer ◽  
Phase Water

During recent years,micro-channel heat transfer technique has been successfully used in many practical situations，and has notable advantages of high heat transfer efficiency and compact configuration.It is an important subject in modern hydrodynamic and heat transfer research field.Computational fluid dynamic program CFX will be used in this article to simulate flow and heat transfer of single-phase water in micro-channel ,flow and temperature felid will be described visually in CFX, and this object is searching a new method to research more flow and heat transfer of single-phase water.

An Analytical Investigation of Forced Convection Heat Transfer to Fluids Near the Thermodynamic Critical Point

1975 ◽  
Vol 97 (2) ◽  
pp. 226-230 ◽  
Author(s):  
V. S. Sastry ◽  
N. M. Schnurr
Keyword(s):  
Heat Transfer ◽  
Critical Point ◽  
Circular Tube ◽  
Convection Heat Transfer ◽  
Analytical Investigation ◽  
Convection Heat ◽  
Thermodynamic Critical Point ◽  
Constant Wall Heat Flux ◽  
Flow Through ◽  
Implicit Finite Difference

A numerical solution is carried out for heat transfer to fluids near the thermodynamic critical point for turbulent flow through a circular tube with constant wall heat flux. An adaptation of the Patankar-Spalding implicit finite difference marching procedure is used. Agreement of the results with experimental data for water and carbon dioxide show the solution to be quite accurate very near the critical point provided the wall temperature at inlet is less than the pseudocritical temperature of the fluid.

Numerical Investigation of Natural Convection Heat Transfer From an Array of Horizontal Fins in Non-Newtonian Power-Law Fluids

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Jacob K. Mulamootil ◽  
Sukanta K. Dash
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Power Law ◽  
Convection Heat Transfer ◽  
Natural Convection Heat Transfer ◽  
Convection Heat ◽  
Flat Plates ◽  
Power Law Fluids ◽  
Power Law Index ◽  
Fin Length

Natural convection heat transfer from an array of horizontal rectangular fins on a vertical flat plate in non-Newtonian power-law fluids has been studied. The underlying physical principles affecting heat transfer were studied using comprehensive solutions obtained from numerical investigations. Heat transfer to the power-law fluid was found to depend on the fluid rheology (power-law index) and significantly on the geometric parameters (interfin spacing, fin length) as well. The dependence was quantified using the Nusselt number (Nu) and fin effectiveness (Q/Q0). The present study shows that compared to a fin analyzed in isolation, the spatial arrangement of multiple fins relative to one another in an array does have a significant effect on the flow field around subsequent fins in power-law fluids. Therefore, the average heat transfer coefficient of the natural convection system is affected significantly. The variation of Nu with the dimensionless fin length (l/L), dimensionless interfin spacing (S/L), and fluid power-law index (n) was plotted. The dependence was found to be counter intuitive to expectations based on studies for natural convection from vertical flat plates to power-law fluids. In the present study involving fins, shear-thinning fluids (n < 1) show a decrease in heat transfer and shear-thickening fluids (n > 1) show an enhancement in heat transfer for higher l/L values. The results of the study may be useful in the design of natural convection systems that employ power-law fluids to enhance or control heat transfer.

Optimizing Heat Transfer Rate in an Internally Cooled Cutting Tool: FE- Based Design Analysis and Experimental Study

2011 ◽  
Vol 496 ◽  
pp. 188-193
Author(s):  
Saiful Che Ghani ◽  
Kai Cheng ◽  
Xi Zhi Sun ◽  
Richard Bateman
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Cutting Tool ◽  
Cutting Temperature ◽  
Channel Structure ◽  
Dominant Factor ◽  
Micro Channel ◽  
Internal Wall ◽  
Cooling Fluid

The machining process produces high local temperatures in the tool-chip and tool-workpiece contact areas, normally lead to negative influence on the machine performance. This paper presents a study on optimizing the internal micro channel structure of a tungsten carbide (WC) cutting tool in order to enhance heat transfer rate when applied with internal cooling fluid. Inspired by water jet impingement theory, the efficiency and heat transfer rate of single phase micro channel mainly depends on the fluid velocity as well as temperature difference between the cooling fluid and hot surface. In this study three variables, i.e. the space between channel and internal wall of the insert, channel diameter and fluid temperature, have been tested with design of experiments (DoE) to study the significance of the factors and interactions between them on cutting temperature. A 3-D finite element (FE) model has been developed to observe the effects of these factors on heat transfer rate. The simulation results show the most dominant factor to affect the cutting temperature is the temperature of the cooling fluid followed by the space between channel and tool insert internal wall.

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