The Effect of Parameter Changes to the Performance of a Triangular Shape Interrupted Microchannel Heat Sink

2012 ◽  
Vol 58 (2) ◽  
Author(s):  
Fudhail Abd Munir ◽  
Mohd Irwan Mohd Azmi ◽  
Nadlene Razali ◽  
Ernie Mat Tokit
Keyword(s):  
Contact Angle ◽  
Pressure Drop ◽  
Heat Sink ◽  
Heat Dissipation ◽  
Thermal Dissipation ◽  
Working Fluid ◽  
Uniform Heat Flux ◽  
Length Width ◽  
Fluent Software ◽  
Phase Water

The effect of parameter changes on triangular shaped interrupted microchannel performance was studied by simulation using FLUENT software. The parameters that were studied are total length, and the contact angle. On the other hand, the investigated effects were pressure drop and platinum film temperature. The flow in microchannel is laminar and single phase. Water was used as the working fluid and the interrupted microchannel is made of silicon. A thin platinum film plate was deposited to provide uniform heat flux. The geometry dimension of the heat sink is 30 mm in length, width of 7 mm and the thickness of 0.525 mm. From the simulation results, it is found that the improvement on heat dissipation may be achieved by increasing the microchannel length at the expense of increase in pressure drop. In addition to that, by reducing the contact angle will result to reduction in term of pressure drop and increases the improvement thermal dissipation.

Heat Transfer and Pressure Drop in a Pin Fin Heat Sink Using Nanofluids as Coolant

2015 ◽  
Vol 1105 ◽  
pp. 253-258 ◽  
Author(s):  
Weerapun Duangthongsuk ◽  
Somchai Wongwises
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Heat Sink ◽  
Heat Transfer Performance ◽  
Working Fluid ◽  
Electric Heater ◽  
Uniform Heat Flux ◽  
Heat Transfer Area ◽  
Pin Fin ◽  
Aluminum Material

This research presents an experimental investigation on the heat transfer performance and pressure drop characteristics of a heat sink with miniature square pin fin structure using nanofluids as coolant. ZnO-water nanofluids with particle concentrations of 0.2, 0.4 and 0.6 vol.% are used as working fluid and then compared with the data for water-cooled heat sink. Heat sink made from aluminum material with dimension around 28 x 33 x 25 mm (width x length x thickness). The heat transfer area and hydraulic diameter of the each flow channel is designed at 1,565 mm2and 1.2 mm respectively. Uniform heat flux at the bottom of heat sink is achieved using an electric heater. The experimental data illustrate that the thermal performance of heat sink using nanofluids as coolant is average 14% higher than that of the water-cooled heat sink. For pressure drop, the data show that the pressure drop of nanofluids is a few percent larger than that of the water-cooled heat sink.

Two-Phase Flow in Microchannels

2001 ◽  
Author(s):  
G. Hetsroni ◽  
A. Mosyak ◽  
Z. Segal
Keyword(s):  
Heat Sink ◽  
High Speed ◽  
Single Phase ◽  
Flow Boiling ◽  
Electronics Cooling ◽  
Working Fluid ◽  
Microchannel Heat Sink ◽  
Two Phase ◽  
Infrared Radiometry ◽  
Phase Water

Abstract Experimental investigation of a heat sink for electronics cooling is performed. The objective is to keep the operating temperature at a relatively low level of about 323–333K, while reducing the undesired temperature variation in both the streamwise and transverse directions. The experimental study is based on systematic temperature, flow and pressure measurements, infrared radiometry and high-speed digital video imaging. The heat sink has parallel triangular microchannels with a base of 250μm. According to the objectives of the present study, Vertrel XF is chosen as the working fluid. Experiments on flow boiling of Vertrel XF in the microchannel heat sink are performed to study the effect of mass velocity and vapor quality on the heat transfer, as well as to compare the two-phase results to a single-phase water flow.

Flow Boiling Heat Transfer in a Silicon Microchannel Heat Sink Using Liquid Crystal Thermography

2008 ◽  
Author(s):  
Ayman Megahed ◽  
Ibrahim Hassan ◽  
Tariq Ahmad
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Heat Sink ◽  
Boiling Heat Transfer ◽  
Flow Boiling ◽  
Heat Fluxes ◽  
Working Fluid ◽  
Microchannel Heat Sink

The present study focuses on the experimental investigation of boiling heat transfer characteristics and pressure drop in a silicon microchannel heat sink. The microchannel heat sink consists of a rectangular silicon chip in which 45 rectangular microchannels were chemically etched with a depth of 295 μm, width of 254 μm, and a length of 16 mm. Un-encapsulated Thermochromic liquid Crystals (TLC) are used in the present work to enable nonintrusive and high spatial resolution temperature measurements. This measuring technique is used to provide accurate full and local surface-temperature and heat transfer coefficient measurements. Experiments are carried out for mass velocities ranging between 290 to 457 kg/m2.s and heat fluxes from 6.04 to 13.06 W/cm2 using FC-72 as the working fluid. Experimental results show that the pressure drop increases as the exit quality and the flow rate increase. High values of heat transfer coefficient can be obtained at low exit quality (xe < 0.2). However, the heat transfer coefficient decreases sharply and remains almost constant as the quality increases for an exit quality higher than 0.2.

Two-Phase Pressure Drop of Ammonia in a Mini/Micro-Channel

2010 ◽  
Author(s):  
M. Hamayun Maqbool ◽  
Bjo¨rn Palm ◽  
R. Khodabandeh ◽  
Rashid Ali
Keyword(s):  
Heat Flux ◽  
Pressure Drop ◽  
Mass Flux ◽  
Homogeneous Model ◽  
Working Fluid ◽  
Uniform Heat Flux ◽  
Internal Diameter ◽  
Two Phase ◽  
Frictional Pressure Drop ◽  
Phase Pressure

Experiments have been performed to investigate two-phase pressure drop in a circular vertical mini-channel made of stainless steel (AISI 316) with internal diameter of 1.70 mm and a uniformly heated length of 245 mm using ammonia as working fluid. The experiments are conducted for heat flux range of 15 to 350 kW/m2 and mass flux range of 100 to 500 kg/m2s. A uniform heat flux is applied to the test section by DC power supply. Two phase frictional pressure drop variation with mass flux, vapour quality and heat flux was determined. The experimental results are compared to predictive methods available in literature for frictional pressure drop. The Homogeneous model and the correlation of Mu¨ller Steinhagen et al. [14] are in good agreement with our experimental data with MAD of 27% and 26% respectively.

scholarly journals Thermal analysis and parametric optimization of plate fin heat sinks under forced air convection

2021 ◽  
pp. 81-81
Author(s):  
Zulfiqar Khattak ◽  
Hafiz Ali
Keyword(s):  
Pressure Drop ◽  
Thermal Resistance ◽  
Heat Sink ◽  
Heat Dissipation ◽  
Parametric Optimization ◽  
Heat Sinks ◽  
Air Velocity ◽  
Forced Air ◽  
Theoretical Results ◽  
Plate Type

Heat dissipation is becoming more and more challenging with the preface of new electronic components having staggering heat generation levels. Present day solutions should have optimized outcomes with reference to the heat sink scenarios. The experimental and theoretical results for plate type heat sink based on mathematical models have been presented in the first part of the paper. Then the parametric optimization (topology optimization) of plate type heat sink using Levenberg-Marquardt technique employed in the COMSOL Multiphysics? software is discussed. Thermal resistance of heat sink is taken as objective function against the variable length in a predefined range. Single as well as multi-parametric optimization of plate type heat sink is reported in the context of pressure drop and air velocity (Reynolds number) inside the tunnel. The results reported are compared with the numerical modeled data and experimental investigation to establish the conformity of results for applied usage. Mutual reimbursements of greater heat dissipation with minimum flow rates are confidently achievable through balanced, heat sink geometry as evident by the presented simulation outcome. About 12% enhancement in pressure drop and up to 51% improvement in thermal resistance is reported for the optimized plate fin heat sink as per data manifested.

Thermo-Fluidic Characteristics in a Cross-Linked Silicon Microchannel Heat Sink

2007 ◽  
Author(s):  
R. Muwanga ◽  
I. Hassan
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Cross Sections ◽  
Heat Sink ◽  
Local Heat Transfer ◽  
Local Heat ◽  
Working Fluid ◽  
Microchannel Heat Sink ◽  
Significant Difference ◽  
The Cross

This paper presents the flow and heat transfer characteristics in a cross-linked silicon microchannel heat sink. The heat sink is composed of 45 channels, 270 μm wide × 285 μm tall in a silicon substrate formed via deep reactive ion etching. A detailed discussion of the pressure drop data reduction is described, including characterization of the channel cross-sections and methods to account for inlet and exit loss coefficients. No significant difference is observed in the pressure drop measurements between the cross-linked and standard heat sinks flowing air and water. The use of un-encapsulated liquid crystal thermography was successfully utilized to obtain local heat transfer data with FC-72 as the working fluid. The heat transfer results show inflections in the thermal profile due to the cross-links.

Waterblock Modelling for GPU Liquid Cooling

2018 ◽  
Author(s):  
Jose-Carlos Vargas-Vazquez ◽  
Jose-Angel Gutierrez-Garcia ◽  
Abel Hernandez-Guerrero ◽  
Luis Luviano-Ortiz ◽  
Jose-Luis Zuñiga-Cerroblanco
Keyword(s):  
Pressure Drop ◽  
Heat Dissipation ◽  
Working Fluid ◽  
Air Cooling ◽  
Liquid Cooling ◽  
Graphic Processor Unit ◽  
Cooling Systems ◽  
Tremendous Amount ◽  
Processor Unit ◽  
Energy And Momentum

Nowadays, cooling of electronic chips is one of the most serious challenges due to the exponential growth in the demand of increasingly powerful computer systems; the overheating of these components has become a problem of high importance. For this reason, the new cooling technologies such as liquid cooling systems replace the conventional air-cooling systems to avoid the effect of hotspots generated on a chip. To make matters worse, the current use of video games is requiring a tremendous amount of energy dissipation, over passing the cooling requirements of CPUs. Therefore, in this paper a new geometry is proposed to keep cool the graphic processor unit (GPU) in a CPU, using water as the working fluid. The main aim of the design is to enhance the heat dissipation in the GPU, decrease the pressure drop during the cooling process and reduce the amount of material used to build the waterblock. A numerical simulation solves the energy and momentum equations. The thermal performance of the proposed geometry is compared with a commercial heat sink geometry previously characterized. The results for the new geometry show that greater heat dissipation is not reached (results are about the same as the results for the commercial geometry) but due to the modification made, there is less pressure drop, while reducing the size of the waterblock. These results make this new geometry quite a good candidate for the new state of the art of cooling waterblocks.

scholarly journals Numerical Optimization of a Microchannel Geometry for Nanofluid Flow and Heat Dissipation Assessment

2021 ◽  
Vol 11 (5) ◽  
pp. 2440
Author(s):  
Inês M. Gonçalves ◽  
César Rocha ◽  
Reinaldo R. Souza ◽  
Gonçalo Coutinho ◽  
Jose E. Pereira ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Sink ◽  
Heat Dissipation ◽  
Jet Impingement ◽  
Experimental Tests ◽  
Heat Sinks ◽  
Working Fluid ◽  
Optimized Design ◽  
Nanofluid Flow ◽  
Microchannel Heat Sinks

In this study, a numerical approach was carried out to analyze the effects of different geometries of microchannel heat sinks on the forced convective heat transfer in single-phase flow. The simulations were performed using the commercially available software COMSOLMultiphysics 5.6® (Burlington, MA, USA) and its results were compared with those obtained from experimental tests performed in microchannel heat sinks of polydimethylsiloxane (PDMS). Distilled water was used as the working fluid under the laminar fluid flow regime, with a maximum Reynolds number of 293. Three sets of geometries were investigated: rectangular, triangular and circular. The different configurations were characterized based on the flow orientation, type of collector and number of parallel channels. The main results show that the rectangular shaped collector was the one that led to a greater uniformity in the distribution of the heat transfer in the microchannels. Similar results were also obtained for the circular shape. For the triangular geometry, however, a disturbance in the jet impingement was observed, leading to the least uniformity. The increase in the number of channels also enhanced the uniformity of the flow distribution and, consequently, improved the heat transfer performance, which must be considered to optimize new microchannel heat sink designs. The achieved optimized design for a heat sink, with microchannels for nanofluid flow and a higher heat dissipation rate, comprised a rectangular collector with eight microchannels and vertical placement of the inlet and outlet.

scholarly journals Evaluation and Optimization of a Cross-Rib Micro-Channel Heat Sink

Micromachines ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 132
Author(s):  
Haiying Chen ◽  
Chuan Chen ◽  
Yunyan Zhou ◽  
Chenglin Yang ◽  
Gang Song ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Aspect Ratio ◽  
Heat Sink ◽  
Heat Dissipation ◽  
Junction Temperature ◽  
Micro Channel ◽  
Test Chip ◽  
Thermal Test ◽  
Micro Channels ◽  
The Cross

This article presents a novel cross-rib micro-channel (MC-CR) heat sink to make fluid self-rotate. For a thermal test chip (TTC) with 100 w/cm2, the cross-ribs micro-channel were compared with the rectangular (MC-R) and horizontal rib micro-channel (MC-HR) heat sinks. The results show that, with the cross-rib micro-channel, the junction temperature of the thermal test chip was 336.49 K, and the pressure drop was 22 kPa. Compared with the rectangular and horizontal ribs heat sink, the cross-rib micro-channel had improvements of 28.6% and 14.3% in cooling capability, but the pressure drop increased by 10.7-fold and 5.5-fold, respectively. Then, the effects of the aspect ratio (λ) of micro-channel in different flow rates were studied. It was found that the aspect ratio and cooling performance were non-linear. To reduce the pressure drop, the inclination (α) and spacing (S) of the cross-ribs were optimized. When α = 30°, S = 0.1 mm, and λ = 4, the pressure drop was reduced from 22 kPa to 4.5 kPa. In addition, the heat dissipation performance of the rectangular, staggered fin (MC-SF), staggered rib (MC-SR) and cross-rib micro-channels were analyzed in the condition of the same pressure drop, MC-CR still has superior heat dissipation performance.

scholarly journals The flow and heat performance of tree-like network heat sink with diverging–converging channel

2021 ◽  
Vol 236 ◽  
pp. 01027
Author(s):  
Xiugen Zhu ◽  
Peng Qian ◽  
Zizhen Huang ◽  
Chengyuan Luo ◽  
Minghou Liu
Keyword(s):  
Pressure Drop ◽  
Flow Rate ◽  
Heat Sink ◽  
Heat Dissipation ◽  
Maximum Temperature ◽  
Pumping Power ◽  
Flow Recirculation ◽  
Converging Channel ◽  
Converging Angle ◽  
Good Heat

A tree-like network heat sink with diverging–converging channel is designed, and effect of flow rate, channel diverging-converging angles on the flow and heat dissipation performance of the tree-like network heat sink is analysed and compared by numerical simulation. Results show that the diverging– converging angle of 2° can reduce the pressure drop by 14% when inlet mass flow rate is 0.00499kg/s. And the maximum temperature, the temperature difference between the maximum and minimum of the heat sink increases by 0.63K and 0.92K respectively. As the diverging-converging angle increases to 4°, however, it only reduces the pressure drop by 13% and can not bring more pressure drop due to formation of flow recirculation inside the tree-like network heat sink channel. Therefore, the diverging–converging fractal micro-channel heat sink with 2° has good heat dissipation performance with obvious lower pumping power.

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