scholarly journals Simulation analysis of heat transfer performance of heat sink with reduced material design

2020 ◽  
Vol 12 (5) ◽  
pp. 168781402092130
Author(s):  
Ya-Chu Chang

The field of electronic device applications is becoming more and more extensive. With the development of science and technology and the improvement of the integration of electronic components, local heating is becoming more and more serious. If heat cannot be discharged immediately, it will cause heat to accumulate, causing the temperature of each component to exceed the limit. The reliability of electronic equipment is greatly reduced. Especially in important fields such as military and aerospace, the thermal reliability of electronic components is higher. The research results show that increasing the Reynolds number is helpful to reduce the overall temperature and thermal resistance of the heat sink, but the increase of the Reynolds number and the decrease of the thermal resistance value are gradually flat. The design concept of material reduction has a significant impact on processing and cost. The results of this article show that selecting the appropriate heat sink fins and matching the specific Reynolds number can effectively improve the heat transfer performance of the heat sink.

Author(s):  
Shuichi Torii ◽  
Wen-Jei Yang

A theoretical study is performed to investigate unsteady thermal and fluid flow transport phenomena over flat fins with heat sink, which are placed in a forced convection environment. Emphasis is placed on the effects of Reynolds number and fin pitch on heat transfer performance and velocity and thermal fields. It is found from the study that (i) in the high Reynolds number region, the alternating changes in the fluid flow take place for larger fin pitch, (ii) the alternating flow in the space area between two fins is mutually interacted by the corresponding one from the adjacent in-line plate fines, resulting in an amplification of heat transfer performance, and (iii) heat-transfer performance is intensified with a decrease in the fin pitch, whose trend becomes larger in the higher Reynolds number region considered here.


Author(s):  
Ruixian Fang ◽  
Wei Jiang ◽  
Jamil Khan ◽  
Roger Dougal

The present work experimentally investigates the thermal effects of a synthetic jet actuator on the heat transfer performance of single-phase flow confined in a microchannel heat sink. The heat sink consisted of a single rectangular microchannel 500 μm wide, 300 μm deep and 26 mm long. Deionized water was employed as the cooling fluid. A synthetic jet actuator with a 100 μm diameter orifice was placed right above the microchannel and 5 mm downstream from the channel inlet. A Unimorph piezoelectric disc bender was employed as the synthetic jet actuator. The effects of the bulk microchannel flow Reynolds number, the synthetic jet operating voltage and frequency on the microchannel heat transfer performance are being investigated. The Reynolds number ranges from 100 to 500. The actuator driving voltage and frequency ranges in 20–180Vp-p and 10–150 Hz respectively. The results from the case without synthetic jet are compared to those with synthetic jet. It shows that the thermal effects of the synthetic jet are functions of the jet driving voltage, frequency, as well as the bulk mass flow rate in the microchannel. For the case of Reynolds number equal 177, around 24% enhancement is achieved under specified jet operating conditions for a single synthetic jet.


2021 ◽  
pp. 142-142
Author(s):  
Ji Choong ◽  
Kok Yu ◽  
Mohd Abdullah

This paper demonstrates a numerical study on heat transfer characteristics of laminar flow in a double-layered oblique finned heat sink using nanofluids with Al2O3 nanoparticles. Microchannel heat sink with primary channel width of 0.5 mm with aspect ratio of 3 is employed. Instead of having conventional straight fins, oblique fins with narrow secondary channels are used. In this numerical study, single-phase fluid model with conjugate heat transfer is considered. The numerical modelling was first validated with existing data for double-layered conventional microchannel heat sink having water (base fluid) as the working fluid. Numerical investigations on oblique finned microchannel heat sink were then conducted for flow rates ranging from 3?10-7 to 15?10-7 m3/s, equivalent to primary channel inlet velocity in between 0.2 and 1.0 m/s. It was found that double-layered oblique finned configuration yields better heat transfer performance, inferred by the lower overall thermal resistance obtained as compared with that of double-layered conventional heat sink. Employing double-layered oblique finned heat sink, the heat transfer performance could be further enhanced, by using nanoparticles that are added into water-based fluid. It is found that the reduction of overall thermal resistance is proportional to the volume fraction of nanoparticles. Using cross flow double-layered oblique finned configuration, the largest reduction in the overall thermal resistance can reach up to 25%, by using nanofluids with 4% volume fraction of Al2O3 nanoparticles.


2014 ◽  
Vol 22 (01) ◽  
pp. 1450005 ◽  
Author(s):  
SHUICHI TORII

This paper aims to study the convective heat transfer behavior of aqueous suspensions of nanoparticles flowing through a horizontal tube heated under constant heat flux condition. Consideration is given to the effects of particle concentration and Reynolds number on heat transfer enhancement and the possibility of nanofluids as the working fluid in various heat exchangers. It is found that (i) significant enhancement of heat transfer performance due to suspension of nanoparticles in the circular tube flow is observed in comparison with pure water as the working fluid, (ii) enhancement is intensified with an increase in the Reynolds number and the nanoparticles concentration, and (iii) substantial amplification of heat transfer performance is not attributed purely to the enhancement of thermal conductivity due to suspension of nanoparticles.


1993 ◽  
Vol 115 (3) ◽  
pp. 560-567 ◽  
Author(s):  
N. Zhang ◽  
J. Chiou ◽  
S. Fann ◽  
W.-J. Yang

Experiments are performed to determine the local heat transfer performance in a rotating serpentine passage with rib-roughened surfaces. The ribs are placed on the trailing and leading walls in a corresponding posited arrangement with an angle of attack of 90 deg. The rib height-to-hydraulic diameter ratio, e/Dh, is 0.0787 and the rib pitch-to-height ratio, s/e, is 11. The throughflow Reynolds number is varied, typically at 23,000, 47,000, and 70,000 in the passage both at rest and in rotation. In the rotation cases, the rotation number is varied from 0.023 to 0.0594. Results for the rib-roughened serpentine passages are compared with those of smooth ones in the literature. Comparison is also made on results for the rib-roughened passages between the stationary and rotating cases. It is disclosed that a significant enhancement is achieved in the heat transfer in both the stationary and rotating cases resulting from an installation of the ribs. Both the rotation and Rayleigh numbers play important roles in the heat transfer performance on both the trailing and leading walls. Although the Reynolds number strongly influences the Nusselt numbers in the rib-roughened passage of both the stationary and rotating cases, Nuo and Nu, respectively, it has little effect on their ratio Nu/Nuo.


2021 ◽  
Author(s):  
Kyle Hassan ◽  
Robert F. Kunz ◽  
David Hanson ◽  
Michael Manahan

Abstract In this work, we study the heat transfer performance and particle dynamics of a highly mass loaded, compressible, particle-laden flow in a horizontally-oriented pipe using an Eulerian-Eulerian (two-fluid) computational model. An attendant experimental configuration [1] provides the basis for the study. Specifically, a 17 bar co-flow of nitrogen gas and copper powder are modeled with inlet Reynolds numbers of 3×104, 4.5×104, and 6×104 and mass loadings of 0, 0.5, and 1.0. Eight binned particle sizes were modeled to represent the known powder properties. Significant settling of all particle groups are observed leading to asymmetric temperature distributions. Wall and core flow temperature distributions are observed to agree well with measurements. In high Reynolds number cases, the predictions of the multiphase computational model were satisfactorily aligned with the experimental results. Low Reynolds number model predictions were not as consistent with the experimental measurements.


2012 ◽  
Vol 197 ◽  
pp. 216-220
Author(s):  
Zhong Chao Zhao ◽  
Rui Ye ◽  
Gen Ming Zhou

To solve the cooling problem in modern electronic device, a kind of heat pipe radiator was designed and manufactured in this paper. The heat transfer performance of heat pipe radiator and its relationship with air velocity were investigated by experimental method. The experimental results show that the heat pipe radiator can meet the temperature requirement of electronic device with the power range from 40W to 160W. To keep the operational temperature of electronic device with power of 160W under 75°C,the air velocity should be keep at 1.7m/s. The heat dissipation performance of heat pipe radiator was enhanced with the air velocity increased from 0.2m/s to 1.7m/s.for the electronic equipment with power of 160W.


Author(s):  
Kazuhisa Yuki ◽  
Masahiro Uemura ◽  
Koichi Suzuki ◽  
Ken-ichi Sunamoto

Two-phase flow loop system using a metal porous heat sink is proposed as a cooling system of the future power electronic devices with a heat load exceeding 300W/cm2. In this paper, as the first step, the heat transfer performance of the porous heat sink is evaluated under high heat flux conditions and the applicability and some engineering issues are discussed. The porous medium, which is fabricated by sintering copper particles, has a functional structure with several sub-channels inside it to enhance phase-change as well as discharge of generated vapor outside the porous medium. This porous heat sink is attached onto a heating chip and removes the heat by evaporating cooling liquid passing through the porous medium against the heat flow. Experiments using 30 kW of heating system show that the heat transfer performance of a copper-particles-sintered porous medium with the sub-channels exceeds 800W/cm2 in both high and low subcooling cases and achieves 300W/cm2 at a wall temperature of 150 °C (Tin = 70 °C) and 130 °C (Tin = 70 °C). These results prove that this porous heat sink is applicable enough for cooling 300 W/cm2 class of power electronic devices.


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