共查询到20条相似文献,搜索用时 78 毫秒
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利用数值模拟方法分析了高度、直径和间距分别为15.0mm、0.1mm和0.5mm的型号1纯铜丝针肋散热器的散热和流动阻力特性,并与相同材料、相同高度,直径和间距分别为1.0mm和5.0mm的型号2在相同边界条件下进行对比。结果表明,前者散热性能高6%,但是后者通过增加丝径和扩大间距进行结构优化,针体总质量没有发生改变,而阻力损失从624.06Pa大幅降低到33.74Pa,并且在工艺上也容易实现。另外,由于两种针肋的针体在13.0~15.0mm高度上温度分布基本没有变化,可以适当降低高度,节省材料。 相似文献
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本文用Icepak软件分别对有热管和无热管散热器进行了数值模拟对比研究,对数值模拟的过程和结果进行分析比较,结果表明有热管散热器的效果明显强于无热管散热器,同时显示了Icepak在电子设备散热研发过程中的重要作用. 相似文献
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对椭圆芯管矩形翅片和大功率晶闸管用热管散热器偏心圆芯管矩形翅片的传热进行了分析和数值模拟,获得了相应的肋效率曲线,并与已有的近似解作了比较。初步考查了偏心度、材料变物性和翅基温度的不均匀性对偏心圆芯管矩形翅片传热的影响。 相似文献
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Xi WU Hong YE Jianxiang WANG Jie HE Jian YANG 《Frontiers of Energy and Power Engineering in China》2012,(2)
The influence of the period of rotation on the effectiveness of the thermophotovoltaic (TPV) rotary regenerator was theoretically and experimentally investigated.It was found that the deviations of the... 相似文献
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Seung-Hwan Yu Kwan-Soo Lee Se-Jin Yook 《International Journal of Heat and Mass Transfer》2011,54(11-12):2499-2505
We investigated natural convection heat transfer around a radial heat sink adapted for dissipating heat on a circular LED (light emitting diode) light and optimized heat sink. The numerical results were validated with experimental results and it showed a good agreement. To select the optimum reference model, three types of heat sinks (L, LM and LMS model) were compared. Parametric studies were performed to compare the effects of the number of fins, long fin length, middle fin length and heat flux on the thermal resistance and average heat transfer coefficient. Finally, multi-objective optimizations considering thermal performance and mass simultaneously were performed and Pareto front were conducted with various weighting factors. It was found that it was impossible to optimize both thermal performance and heat sink mass at the same time, and there existed an upper limit to the ratio of weighting factors (ω1/ω2). 相似文献
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Cheng-Hung Huang Jon-Jer Lu Herchang Ay 《International Journal of Heat and Mass Transfer》2011,54(7-8):1482-1492
A three-dimensional heat sink module design problem is examined in this work to estimate the optimum design variables using the Levenberg–Marquardt Method (LMM) and a general purpose commercial code CFD-ACE+. Three different types of heat sinks are designed based on the original fin arrays with a fixed volume. The objective of this study is to minimize the maximum temperature in the fin array and to determine the best shape of heat sink. Results obtained by using the LMM to solve this 3-D heat sink module design problem are firstly justified based on the numerical experiments and it is concluded that for all three cases, the optimum fin height H tends to become higher and optimum fin thickness W tends to become thinner than the original fin array, as a result both the fin pitch D and heat sink base thickness U are increased. The maximum temperature for the designed fin array can be decreased drastically by utilizing the present fin design algorithm. Finally, temperature distributions for the optimal heat sink modules are measured using thermal camera and compared with the numerical solutions to justify the validity of the present design. 相似文献
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A channel with a height- or width-tapered variation is designed to improve the thermal performance of a microchannel heat sink (MCHS). To this end, a three-dimensional MCHS model is constructed to analyze the effects of the height- and width-tapered ratios on the thermal performance of the MCHS. The thermal resistance and temperature distribution are taken as the thermal performance indicators. Numerical predictions show that the relationship between the thermal resistance and the width-tapered ratio is not monotonic at the fixed pumping power. The thermal resistance first decreases and then increases. A similar behavior is also exhibited by the height-tapered ratio. However, the height-tapered ratio effects can be negligible. It is also found that the width-tapered-channel design has a lower and a relatively uniform temperature distribution compared to parallel or height-tapered channel design. Moreover, the MCHS with width-tapered channel design showed a maximum enhancement in thermal performance of around 16.7% over that of the parallel-channel design when the pumping power is larger than 0.4 W. 相似文献
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Gaeet AlFalah Taher S. Maatallah Mussad Alzahrani Fahd Ghallab Al-Amri 《国际能源研究杂志》2020,44(14):11852-11871
Nowadays, the most recent optical configuration based on Cassegrain and Fresnel lens designs of concentrator photovoltaic(CPV) has shown a race to achieve the ultrahigh concentration ratio. Still, none of those has experimentally shown an optical concentration ratio (GC) beyond 2000 suns. This is because their energy concentration ratios are challenged by the excessive temperature raised throughout the optical stages, which diminishes the efficiency of the solar cell. In this context, this research work aims to numerically investigate a microscale pin-fins heat sink configuration to enhance the thermal performance and the cost-competitivity of ultrahigh CPV thermal receiver. The impacts of the solar cell area, cell efficiency, and heat sink's material have been analyzed and discussed. The results showed that a circular pin-fins heat sink could accomplish a drop of 23.28% in the maximum operating cell temperature at 10 000 suns for cell area of 1 × 1 mm2 relatively compared to the conventional flat-plate heat sink. Furthermore, for a circular pin-fins heat sink with a cell area of 2 × 2 mm2, the cell temperature started exceeding the safe operating range of temperature (80°C) at 8000 suns with an average temperature of 96.1°C and reaching a maximum of 113.91°C at 10 000 suns. A gradient temperature on the planar direction of the aluminum circular pin-fins heat sink was about 1.187°C at 10 000 suns whereas 0.703°C was recorded in the case of a copper circular pin-fins heat sink. The circular pin-fins heat sink showed the highest thermal performance resulting in maintaining the solar cell temperature within its safe operating range even beyond 10 000 suns. From an economic point of view, aluminum circular pin-fins heat sink has been found to be less costly than the copper one. Finally, it was found that at 8000 suns, the flat-plate heat sink cost is more expensive than the traditional pin-fins heat sink by 14.7%, where the flat-plate heat sink becomes the worst economic configuration at 10 000 suns. At that concentration ratio, the cost has increased by 43.38%, 5.75%, and 10.61% compared to the traditional pin-fins heat sink, cylindrical pin-fins heat sink, and circular pin-fins heat sink, respectively. 相似文献
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In this paper, the finite element method (FEM) and experiment were adopted to evaluate the thermal performance of a multi-chip COB LED lamp based on the cold spray technology. The results show that the junction temperature can be limited under 110 °C. Compared to an aluminum-substrate LED module pressed on the heat sink, the soldering structure of a copper-substrate LED can reduce the junction temperature. The junction temperature of the LED module soldered on the heat sink is only 97.3 °C, while one of the pressing structures is 103.5 °C. It is further found that the chip gaps and the thickness of the copper-circuit layer have significant effect on the heat spread. Increasing the chip gaps and the thickness of the copper-circuit layer can effectively reduce the junction temperature and improve the LED lamp's thermal performance. 相似文献
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A simplified model predicting the heat transfer performance of a heat sink base with a high thermal conductivity was developed.
Numerical analysis was performed using the commercial software FLUENT. The investigation indicates that for heat sink bases
with a high effective thermal conductivity, such as the base embedded with a typical heat pipe, the entire heat sink can be
modeled as a flat plate with a uniform temperature and an effective convection heat transfer coefficient. This simplified
model can be used to determine the heat transfer performance of a heat sink embedded with a typical heat pipe or vapor chamber. 相似文献
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Yue-Tzu Yang Huan-Sen Peng 《International Journal of Heat and Mass Transfer》2008,51(19-20):4788-4796
This study presents the numerical simulation of the heat sink with an un-uniform fin height with a confined impingement cooling. The governing equations are discretized by using a control-volume-based finite-difference method with a power-law scheme on an orthogonal non-uniform staggered grid. The coupling of the velocity and the pressure terms of momentum equations are solved by the SIMPLEC algorithm. The well-known k–ε two-equations turbulence model is employed to describe the turbulent structure and behavior. The parameters include the Reynolds number (Re = 15,000 and Re = 25,000) and 12 un-uniform fin height designs (Type-b to Type-m). The objective of this study is to examine the effects of the fin shape of the heat sink on the thermal performance. It is found that the junction temperature can be reduced by increasing the fin height near the center of the heat sink. The results also show that there is a potential for optimizing the un-uniform fin height design. 相似文献
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A simplified model predicting the heat transfer performance of a heat sink base with a high thermal conductivity was developed. Numerical analysis was performed using the commercial software FLUENT. The investigation indicates that for heat sink bases with a high effective thermal conductivity, such as the base embedded with a typical heat pipe, the entire heat sink can be modeled as a flat plate with a uniform temperature and an effective convection heat transfer coefficient. This simplified model can be used to determine the heat transfer performance of a heat sink embedded with a typical heat pipe or vapor chamber. 相似文献
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H. Abbassi 《Energy》2007
Present investigation analyzes the issue of entropy generation in a uniformly heated microchannel heat sink (MCHS). Analytical approach used to solve forced convection problem across MCHS, is a porous medium model based on extended Darcy equation for fluid flow and two-equation model for heat transfer. Simultaneously, closed form velocity solution in a rectangular channel is employed to capture z-directional viscous effect diffusion and its pronounced effect on entropy generation through fluid flow. Subsequently, governing equations are cast into dimensionless form and solved analytically. Second law analysis of problem is then conducted on the basis of obtained velocity and temperature fields and expressions for local and average entropy generation rate are derived in dimensionless form. Average entropy generation rate is then utilized as a criterion for assessing the system performance. Finally, the effect of influential parameters such as, channel aspect ratio (αS), group parameter (Br/Ω), thermal conductivity ratio (C) and porosity (ε) on thermal and total entropy generation is investigated. In order to examine the accuracy of the analysis, the results of thermal evaluation are compared to one of the previous investigations conducted for thermal optimization of MCHS. 相似文献