Microchannel Simulation (original) (raw)
Related papers
Thermal and hydrodynamic analysis of microchannel heat sinks: A review
Renewable and Sustainable Energy Reviews, 2013
An impressive amount of investigation has been devoted to enhancing overall thermal and hydrodynamic performance of microchannel heat sinks. The small size of microchannel heat sinks and their ability to dissipate heat generated by modern electronics makes them the first choice for the electronic cooling systems in most devices. In this paper, a comprehensive review of available studies regarding non-circular microchannel heat sinks, with emphasis on rectangular microchannels, was presented and analyzed. This review looked into the methodologies used to analyze and optimize the overall performance of microchannel systems along with channel geometries, flow conditions, the coolants used, structural materials, optimization tools and finally, the form in which the final outcome of each study was presented. The review showed that earlier studies (from 1981 to 1999) were largely conducted using experimental or analytical approaches while more recent studies (from 2000 to the end of 2012) showed a dependency on numerical simulations and evolutionary algorithms. In addition, they also showed that laminar was the prevailing flow condition as out of the 69 articles reviewed, 54 employed laminar flows. Furthermore, the use of liquid coolants was preferable over gaseous coolants. Recent developments in nanofluids are providing alternative coolants that are quickly establishing as coolants to be reckoned with.
Heat Transfer Analysis of Microchannel using Fluids
2020
In recent time due to high performance of electronic component the heat generation is increasing drastically. Due to this scenario heat dissipation becomes a major issue in efficiency promation and stable operation. Silicon based microchannel heat sink fabricated using semiconductor production technique plays important role in cooling devices. The effect of the thermophysical properties of working fluids on the performance of microchannel is tested or we can say investigated. For this purpose the different working fluids are selected. water, hepthane, ammonia, methanol, and ethanol. KeywordsHeat transfer, Micro channel, different coolents, natural convection, heat transfer, heat sink, , cooling, micro heat sinks. I.INTRODUCTION Now a days the electronic devices become compact. Due to compactness of this devices there is huge heat generation in this devices. Hence for the safety purpose heat should be remove from this devices continuosly.so the purpose of cooling system is to maintai...
A review of liquid flow and heat transfer in microchannels with emphasis to electronic cooling
Sādhanā
Since the realization of microchannel devices more than three and half decades ago with water as the cooling fluid providing heat transfer enhancement, significant progress has been made to improve the cooling performance. Thermal management for electronic devices with their ever-widening user profile remains the major driving force for performance improvement in terms of miniaturisation, long-term reliability, and ease of maintenance. The ever-increasing requirement of meeting higher heat flux density in more compact and powerful electronic systems calls for further innovative solutions. Some recent studies indicate the promise offered by processes with phase change and the use of active devices. But their adoption for electronic cooling still weighs unfavourably against long-term fluid stability and simplicity of device profile with moderate to high heat transfer capability. Applications and reviews of these promising research trends have been briefly visited in this work. The main focus of this review is the flow and heat transfer regime related to electronic cooling in evolving channel forms, whose fabrication are being enabled by the significant advancement in micro-technologies. Use of disruptive wall structures like ribs, cavities, dimples, protrusions, secondary channels and other interrupts along with smooth-walled channels with curved flow passages remain the two chief geometrical innovations envisaged for these applications. These innovations target higher thermal enhancement factor since this implies more heat transfer capability for the same pumping power in comparison with the corresponding straight-axis, smooth-wall channel configuration. The sophistication necessary to deal with the experimental uncertainties associated with the micron-level characteristic length scale of any microchannel device delayed the availability of results that exhibited acceptable matching with numerical investigations. It is indeed encouraging that the experimental results pertaining to simple smooth channels to grooved, ribbed and curved microchannels without unreasonable increase in pumping power have shown good agreement with conventional numerical analyses based on laminar-flow conjugate heat-transfer model with no-slip boundary condition. The flow mechanism with the different disruptive structures like dimple, cavity and rib, fin and interruption, vortex generator, convergingdiverging side walls or curved axis are reviewed to augment the heat transfer. While the disruptions cause heat transfer enhancement by interrupting the boundary layer growth and promoting mixing by the shed vortices or secondary channel flow, the flow curvature brings in enhancement by the formation of secondary rolls culminating into chaotic advection at higher Reynolds number. Besides these revelations, the numerical studies helped in identifying the parameter ranges, promoting a particular enhancement mechanism. Also, the use of modern tools like Poincare section and the analysis of flow bifurcation leading to chaotic advection is discussed. Among the different disruptive structures, sidewall cavity with rib on the bottom wall within the cavity plays a significant role in augmenting the thermal performance. Among the different converging-diverging side walls or curved axis, the sinusoidal channel provides the highest mixing by the introduction of secondary vortices or dean vortices to augment the heat transfer with less pressure drop. The optimum geometry in terms of high heat transfer with low pressure plays a major role in the design of heat sink. Directions of some future research are provided at the end.
IJERT-Heat Transfer Analysis of Microchannel using Fluids
International Journal of Engineering Research and Technology (IJERT), 2020
https://www.ijert.org/heat-transfer-analysis-of-microchannel-using-fluids https://www.ijert.org/research/heat-transfer-analysis-of-microchannel-using-fluids-IJERTV9IS070503.pdf In recent time due to high performance of electronic component the heat generation is increasing drastically. Due to this scenario heat dissipation becomes a major issue in efficiency promation and stable operation. Silicon based microchannel heat sink fabricated using semiconductor production technique plays important role in cooling devices. The effect of the thermophysical properties of working fluids on the performance of microchannel is tested or we can say investigated. For this purpose the different working fluids are selected. water, hepthane, ammonia, methanol, and ethanol.
Numerical Modelling of Heat Transfer in Rectangular Microchannels
ASME 2nd International Conference on Microchannels and Minichannels, 2004
The paper presents both three and two-dimensional numerical analysis of convective heat transfer in microchannels. The three-dimensional geometry of the microchannel heat sink followed the details of the experimental facility used during a previous research step. The heat sink consisted of a very high aspect ratio rectangular microchannel. Two channel heights, namely 1mm and 0.3mm (0.1mm), were used for 3D (2D) numerical model respectively. Water was employed as the cooling liquid. The Reynolds number ranged from 200 to 3000. In the paper, the thermal entrance effect is analyzed in terms of heat transfer efficiency. Finally, the comparison between measured and computed heat flux and temperature fields is presented.
Simulation of Different Geometries and Flow Parameters of the Micro channel Heat Sinks
Micro channel Heat Sinks are used for heat transfer for miniature electronic circuits. The high performance of the micro channel depends upon the number of parameters like geometrical & flow parameters. There is wide variation in the performance of the micro channel heat sinks as the geometry of these channels changes. The performance is measured in terms of the thermal resistance of the channels. A three- dimensional numerical model of the interrupted micro channel heat sink is presented to study the effect of pumping power and thermal resistance and heat transfer characteristics due to various dimensions of micro channel. Numerical investigation was conducted to predict pumping power and thermal resistance in a rectangular cross section micro channel heat sink by numerical analysis of different geometries. The pumping power and thermal resistance was analysed with different cooling liquid used as water and ethylene glycol while micro channel substrate used was made of copper. The fluid flow and heat transfer mechanism of the newly proposed micro channel heat sink are analysed. Keywords: Simulation; Heat sinks; microelectronic; electronic circuits.
Numerical Analysis of Microchannels Designed for Heat Sinks
Nanomanufacturing and Metrology
Conjugate heat transfer is numerically investigated using a three-dimensional computational fluid dynamics approach in various microchannel geometries to identify a high-performance cooling method for piezoelectric ceramic stacks and spindle units in high-precision machines. Straight microchannels with rectangular cross sections are first considered, showing the performance limitations of decreasing the size of the microchannels, so other solutions are needed for high applied heat fluxes. Next, many microchannel designs, focusing on streamwise geometric variation, are compared to straight channels to assess their performances. Sinusoidally varying channels produce the highest heat transfer rates of those studied. Thus, their optimization is considered at a channel width and height of 35 and 100 μm, respectively. Heat transfer increases as the amplitude and spatial frequencies of the channels increase due to increased interfacial surface area and enhanced Dean flow. The highest perfo...
Numerical simulation of heat transfer in rectangular microchannel
Advances in Applied …, 2009
Numerical simulation of heat transfer in a high aspect ratio rectangular microchannel with heat sinks has been conducted, similar to an experimental study. Three channel heights measuring 0.3 mm, 0.6 mm and 1 mm are considered and the Reynolds number varies from 300 to 2360, based on the hydraulic diameter. Simulation starts with the validation study on the Nusselt number and the Poiseuille number variations along the channel streamwise direction. It is found that the predicted Nusselt number has shown very good agreement with the theoretical estimation, but some discrepancies are noted in the Poiseuille number comparison. This observation however is in consistent with conclusions made by other researchers for the same flow problem. Simulation continues on the evaluation of heat transfer characteristics, namely the friction factor and the thermal resistance. It is found that noticeable scaling effect happens at small channel height of 0.3 mm and the predicted friction factor agrees fairly well with an experimental based correlation. Present simulation further reveals that the thermal resistance is low at small channel height, indicating that the heat transfer performance can be enhanced with the decrease of the channel height.
Applied Thermal Engineering
Microchannel heat sinks are pointed to have a great potential in cooling systems. This paper presents a systematic study to develop a microchannel heat sink to be used in PV panels cooling. A systematic experimental approach is used to optimize the heat sink geometry. Then the potential advantage of using flow boiling conditions is explored in both numerical and experimental approaches. The results show that a heat exchanger with thin walls and wide channels can dissipate a greater amount of heat. Comparing the results obtained for one and two-phase flow conditions, one must conclude that although in the boiling tests the heat transfer coefficient was higher, the cooling method with single-phase flow using water dissipated a greater amount of heat, which was mainly due to flow instabilities. In this context, the numerical work clearly evidences that boiling can be an advantage in microchannel heat sinks, as long as the flow is controlled. The work also shows that the considered numerical simulation tool is sensitive enough to quantify the heat transfer enhancement due to boiling within the examined microchannel paths.
Heat Transfer Properties in Microchannel by Varying Aspect Ratio: Experimental and Simulation
International Journal of Innovative Technology and Exploring Engineering, 2019
In this paper study the heat transfer rate in a branched and rectangular micro channel. Using the aspect ratio of height and width were 1:1 for straight channel and 0.75/1 for branched channel. This experiment was done for same convective area 60 mm2 . This experiment was study how to affect the aspect ratio to temperature drop. The change of effect the aspect ratio we are found by simulation by using the other branch channel aspect ratio (1) or straight micro channel aspect ratio (1.37) and the same area 47mm2 . These different aspect ratio straight and branched channels compare to each other. Then studied after this experimental data as a function of aspect ratio increase the 20% of friction constant evidence at low aspect ratio. Then the wall temperature is carried 92⁰c and heating the heat sink at 90 watts. Using the convective heat transfer in the micro-channel. Study the effect of varying aspect ratio for both branched and rectangular micro-channel has analysed in this study a...