An Experimental Study on the Effect of Configuration of Multiple Microchannels on Heat Removal for Electronic Cooling

2010 ◽  
Author(s):  
Jingru Zhang ◽  
Shaurya Prakash ◽  
Yogesh Jaluria ◽  
Lei Lin
Keyword(s):  
Heat Transfer ◽  
Heat Sink ◽  
Heat Removal ◽  
Electronic Cooling ◽  
Heat Sinks ◽  
Flow Loop ◽  
Labview Software ◽  
Chemical Etch ◽  
Potential Applications

This paper presents the design, fabrication, and characterization of three different configurations of multiple microchannel heat sink devices to improve their overall cooling efficiency for potential applications in electronic cooling. A fabrication and packaging process based on standard UV-lithography, wet etching, and bonding was developed to allow a rapid parametric study. An anisotropic chemical etch with potassium hydroxide, water, and isopropanol is used to fabricate microchannels on (110)-oriented silicon wafers. PDMS (Polydimethylsiloxane) was tested as the cover of microchannels due to its mechanical flexibility. It is transparent so that the microchannel flow can be visualized using a microscope. An open flow loop, which consists of syringe pump and a power supply, was designed to test the heat sinks with different configurations. Temperature data were collected at different locations by a Data Acquisition (DAQ) system and recorded by Labview software to investigate the heat transfer characteristics of the heat sink. Three heat sinks, with different configurations, were tested. They all included microchannels of width 50 μm, depth 60 μm, and fin width 200 μm. Some Typical results on heat transfer are presented, along with discussion on the efficiency for heat removal.

Heat Transfer Analysis of Supercritical Methane in Microchannels with Different Geometric Configurations On High Power Electromechanical Actuator

2022 ◽  
Author(s):  
Zhigang Gao ◽  
Tianhu Wang ◽  
Yuxin Yang ◽  
Xiaolong Shang ◽  
Junhua Bai ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Performance ◽  
High Power ◽  
Heat Sink ◽  
Heat Removal ◽  
Electrical Equipment ◽  
Heat Sinks ◽  
Electromechanical Actuator ◽  
Regenerative Cooling ◽  
Geometric Configurations

Abstract The issue of regenerative cooling is one of the most important key technologies of flight vehicles, which is applied into both the engine and high-power electrical equipment. One pattern of regenerative cooling channels is the microchannel heat sinks, which are thought as a prospective means of improving heat removal capacities on electrical equipment of smaller sizes. In this paper, three numerical models with different geometric configurations, namely straight, zigzag, and sinusoid respectively, are built to probe into the thermal hydraulic performance while heat transfer mechanism of supercritical methane in microchannel heat sinks for the heat removal of high-power electromechanical actuator is also explored. In addition, some crucial influence factors on heat transfer such as inlet Reynolds number, operating pressure and heating power are investigated. The calculation results imply the positive effect of wavy configurations on heat transfer and confirm the important effect of buoyancy force of supercritical methane in channels. The heat sinks with wavy channel show obvious advantages on comprehensive thermal performance including overall thermal performance parameter ? and thermal resistance R compared with that of the straight one. The highest Nu and average heat transfer coefficient am appear in the heat sink with zigzag channels, but the pumping power of the heat sink with sinusoidal channels is lower due to the smaller flow loss.

Heat Transfer Enhancement in the Heat Sinks for Electronic Cooling Applications

2005 ◽  
Author(s):  
Evan Small ◽  
Sadegh M. Sadeghipour ◽  
Mehdi Asheghi
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Heat Transfer Enhancement ◽  
Heat Sink ◽  
Engineering Students ◽  
Electronic Cooling ◽  
Heat Sinks ◽  
Optimum Number ◽  
Transfer Enhancement

In a design competition by the mechanical engineering students at Carnegie Mellon University, which was the design of heat sinks for electronic cooling applications, twenty seven heat sinks were designed and tested for thermal performance. A heat sink with three rows of 9, 8, and 9 dimpled rectangular fins (staggered configuration) demonstrated the best performance in the test. This heat sink even had the least total volume (about 25% less than the set value). This paper reports on an effort made to verify and quantify the role of dimples on heat transfer enhancement of the heat sinks. This includes measurements and simulations of the thermal fluid properties of the heat sinks with and without dimples. Results of both the measurements and simulations indicate that dimples do in fact improve heat transfer capability of the heat sinks. Albeit, dimpled fins cause more pressure drop in air along the heat sink. Keeping the total volume of the heat sink and the height of the fins constant and changing the number of the fins and their arrangement show that there exist an optimum number of fins for the best performance of the heat sink. However, this number of fins is different for inline and staggered arrangements. To check the role of the roughness type on the heat transfer behavior of the fins, a heat sink with twenty-seven bumped fins with inline arrangement was also simulated. Results indicated that bumps increase both thermal resistance and pressure drop relative to that of the heat sinks with plain fins.

Numerical Investigation of Heat Transfer Enhancement in Heat Sinks With Elongated Hexagonal Fins

2011 ◽  
Author(s):  
Zahra Kheirandish ◽  
Haleh Shafeie ◽  
Omid Abouali
Keyword(s):  
Heat Transfer ◽  
Heat Sink ◽  
Numerical Study ◽  
Heat Removal ◽  
Heat Sinks ◽  
Navier Stokes ◽  
Liquid Region ◽  
3 Dimensional ◽  
Solid Region ◽  
Energy Equations

A numerical study was performed for the laminar forced convection of water over a bank of staggered micro fins with cross section of the elongated hexagon. A 3-dimensional mathematical model, for conjugate heat transfer in both solid and liquid is developed. For this aim the Navier-Stokes and energy equations for the liquid region and the energy equation for the solid region are solved simultaneously and the pressure drop as well as the heat transfer characteristics was investigated. The length and width of the studied heat sinks are one centimeter and different heights in the range of 200–500 micrometer were examined for the fluid media. The heat removal of the finned heat sink is compared with an optimum simple mirochannel heat sink. The comparison which is presented at equal pumping powers depicts the enhancement of the heat removal for some specific sizes of the finned heat sink.

Comparison of the Effect of Embedded Grooves on the Heat Removal and Pressure Drop in Microchannel Heat Sinks

2011 ◽  
Author(s):  
Farnaz Faily ◽  
Haleh Shafeie ◽  
Omid Abouali
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Heat Sink ◽  
Heat Removal ◽  
Heat Sinks ◽  
Coefficient Of Performance ◽  
Maximum Heat ◽  
Different Types ◽  
Microchannel Heat Sinks ◽  
Fin Thickness

This paper presents a numerical study for the single phase heat transfer of water in the heat sinks with different types of the grooved microchannels. The cross section of the grooves is either rectangular or arced shape. The grooves are embedded vertically in the side walls of the microchannel but for the floor, different orientation angles of the grooves in the range of 0–60° are investigated. As well, for the grooves on the floor of the channel, the chevron-shape is another pattern which has bee studied. A 3-D computational model is developed for each of the studied cases and the conjugate heat transfer in both solid and liquid is investigated. The governing equations are solved numerically to determine the pressure drop and heat transfer through the heat sink. The results of the heat removal and coefficient of performance (COP) for different types of the grooved microchannel heat sinks are compared to each other as well with those for a simple microchannel heat sink with minimum fin thickness. The comparison shows that the case with minimum vertical fin thickness and arc grooves aligned in 60° on the floor has the maximum heat removal and COP among the studied cases.

Heat Sinks With Enhanced Heat Transfer Capability for Electronic Cooling Applications

2005 ◽  
Vol 128 (3) ◽  
pp. 285-290 ◽  
Author(s):  
Evan Small ◽  
Sadegh M. Sadeghipour ◽  
Mehdi Asheghi
Keyword(s):  
Heat Transfer ◽  
Thermal Performance ◽  
Heat Sink ◽  
Engineering Students ◽  
Electronic Cooling ◽  
Heat Sinks ◽  
Optimum Number ◽  
Transfer Capability ◽  
Improve Heat Transfer ◽  
Heat Transfer Capability

In a competition at Carnegie Mellon University, the mechanical engineering students designed and manufactured 27 heat sinks. The heat sinks were then tested for thermal performance in cooling a mock processor. A heat sink with three rows of 9, 8, and 9 dimpled rectangular fins in staggered configuration performed the best, while having the least total volume (about 25% less than the set value). Validation of the observed thermal performance of this heat sink by experimentation and numerical simulations has motivated the present investigation. Thermal performance of the heat sinks with and without dimples have been evaluated and compared. Results of both the measurements and simulations indicate that dimples do in fact improve heat transfer capability of the heat sinks. However, dimples cause more pressure drop in the air flow. Keeping the total volume of the heat sink and the height of the fins constant and changing the number of the fins and their arrangement show that there is an optimum number of fins for the best performance of the heat sink. The optimum fin numbers are different for inline and staggered arrangements.

Fluid Flow and Heat Transfer of Liquid Sodium in Small-Scale Heat Sinks With Different Geometries

2021 ◽  
Author(s):  
Mahyar Pourghasemi ◽  
Nima Fathi
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Cross Sections ◽  
Heat Sink ◽  
Volume Ratio ◽  
Heat Sinks ◽  
Liquid Sodium ◽  
Small Scale ◽  
Nusselt Numbers ◽  
The Difference

Abstract 3-D numerical simulations are performed to investigate liquid sodium (Na) flow and the heat transfer within miniature heat sinks with different geometries and hydraulic diameters of less than 5 mm. Two different straight small-scale heat sinks with rectangular and triangular cross-sections are studied in the laminar flow with the Reynolds number up to 1900. The local and average Nusselt numbers are obtained and compared against eachother. At the same surface area to volume ratio, rectangular minichannel heat sink leads to almost 280% higher convective heat transfer rate in comparison with triangular heat sink. It is observed that the difference between thermal efficiencies of rectangular and triangular minichannel heat sinks was independent of flow Reynolds number.

Stacked Microchannel Heat Sinks for Liquid Cooling of Microelectronic Components

2000 ◽  
Author(s):  
X. Wei ◽  
Y. Joshi
Keyword(s):  
Flow Rate ◽  
Heat Sink ◽  
Water Flow Rate ◽  
Heat Removal ◽  
Single Layer ◽  
Heat Sinks ◽  
Computationally Efficient ◽  
Liquid Cooling ◽  
Number Of Layers ◽  
Microelectronic Components

Abstract A novel heat sink based on a multi-layer stack of liquid cooled microchannels is investigated. For a given pumping power and heat removal capability for the heat sink, the flow rate across a stack of microchannels is lower compared to a single layer of microchannels. Numerical simulations using a computationally efficient multigrid method [1] were carried out to investigate the detailed conjugate transport within the heat sink. The effects of the microchannel aspect ratio and total number of layers on thermal performance were studied for water as coolant. A heat sink of base area 10 mm by 10 mm with a height in the range 1.8 to 4.5 mm (2–5 layers) was considered with water flow rate in the range 0.83×10−6 m3/s (50 ml/min) to 6.67×10−6 m3/s (400 ml/min). The results of the computational simulations were also compared with a simplified thermal resistance network analysis.

Pin-Fin Heat Sink With Horizontal Base and Blocked Edges

2008 ◽  
Author(s):  
D. Sahray ◽  
H. Shmueli ◽  
N. Segal ◽  
G. Ziskind ◽  
R. Letan
Keyword(s):  
Heat Transfer ◽  
Free Convection ◽  
Contact Resistance ◽  
Cross Section ◽  
Heat Input ◽  
Heat Sink ◽  
Numerical Study ◽  
Heat Sinks ◽  
Transfer Enhancement ◽  
Pin Fin

In the present work, horizontal-base pin fin heat sinks exposed to free convection in air are studied. They are made of aluminum, and there is no contact resistance between the base and the fins. For the same base dimensions the fin height and pitch vary. The fins have a constant square cross-section. The edges of the sink are blocked: the surrounding insulation is flush with the fin tips. The effect of fin height and pitch on the performance of the sink is studied experimentally and numerically. In the experiments, the heat sinks are heated using foil electrical heaters. The heat input is set, and temperatures of the base and fins are measured. In the corresponding numerical study, the sinks and their environment are modeled using the Fluent 6 software. The results show that heat transfer enhancement due to the fins is not monotonic. The differences between sparsely and densely populated sinks are analyzed for various fin heights. Also assessed are effects of the blocked edges as compared to the previously studied cases where the sink edges were exposed to the surroundings.

scholarly journals Cooling Performance of Heat Sinks Used in Electronic Devices

2018 ◽  
Vol 171 ◽  
pp. 02003
Author(s):  
Ibrahim Mjallal ◽  
Hussein Farhat ◽  
Mohammad Hammoud ◽  
Samer Ali ◽  
Ali AL Shaer ◽  
...  
Keyword(s):  
Heat Sink ◽  
Electronic Devices ◽  
Heat Fluxes ◽  
Electronic Cooling ◽  
Heat Sinks ◽  
Passive Cooling ◽  
Short Term ◽  
Cooling Systems ◽  
Thermal Output ◽  
Electrical Devices

Existing passive cooling solutions limit the short-term thermal output of systems, thereby either limiting instantaneous performance or requiring active cooling solutions. As the temperature of the electronic devices increases, their failure rate increases. That’s why electrical devices should be cooled. Conventional electronic cooling systems usually consist of a metal heat sink coupled to a fan. This paper compares the heat distribution on a heat sink relative to different heat fluxes produced by electronic chips. The benefit of adding a fan is also investigated when high levels of heat generation are expected.

Sign in / Sign up

Export Citation Format

Share Document