Thermal Performance Analysis for Optimal Passive Cooling Heat Sink Design

Recent advances in semiconductor technology show the improvement of fabrication on electronics appliances in terms of performance, power density and even the size. This great achievement however led to some major problems on thermal and heat distribution of the electronic devices. This thermal problem could reduce the efficiency and reliability of the electronic devices. In order to minimize this thermal problem, an optimal cooling techniques need to be applied during the operation. There are various cooling techniques have been used and one of them is passive pin fin heat sink approach. This paper focuses on inline pin fin heat sink, which use copper material with different shapes of pin fin and a constant 5.5W heat sources. The simulation model has been formulated using COMSOL Multiphysics software to stimulate the pin fin design, study the thermal distribution and the maximum heat profile

Analytical and numerical predictions of the thermal performance of multi-layered lattice structures

The recent development of additive manufacturing has allowed complex geometries such as multi-layered lattice structures to be designed for different applications, including heat transfer. Performing Computational Fluid Dynamics (CFD) analyses on each new design iteration of lattice structures would require high computational time and cost. An analytical model has therefore been developed, able to rapidly and cost-effectively predict the heat transfer of complex lattice structures. The numerical code has been written for a given multi-layered lattice sample and a two-step approach with fin analogy has been applied to determine the mean outlet fluid temperature and the total heat dissipation for air as the working fluid. CFD simulations have also been performed and results compared to the analytical ones. A very good agreement is obtained between numerical and analytical results under the defined industrial operating conditions of the complex lattice structures, showing that such analytical model can be quickly and efficiently applied to evaluate the thermal performance of multi-layered lattice structures

Thermal Analysis of Staggered Pin Fin Heat Sink for Central Processing Unit

The advancement of microelectronics technology in producing high clock speed and power density’s central processor unit (CPU) indirectly related to thermal management issue. This is a major challenge to the manufacturers, designers and researchers to find the optimum design of the cooling system. If the problem is not being tackled, it will become a major setback to the development of electronic components and devices in the next five to ten years. The most popular technique used in the electronic devices is a metal heat sink with high heat transfer rate. The choice and suitable for the optimal heat sink design are needed in order to control and increase the heat dissipation. In this paper, 3D simulation staggered pin fin heat sink is designed and analyzed using COMSOL Multiphysics software. The finding of this study then is used to propose an optimal staggered pin fin arrangement of heat sink design that could give better thermal performance

SPATIAL SPICE MODEL OF A WIRELESS SENSOR NETWORK NODE BASED ON A THERMOELECTRIC GENERATOR

This paper presents a spatial SPICE model of a wireless sensor network node that enables simulation of performances in the steady-state and time-domain. The model includes constructive non-electrical parts of the node and a thermoelectric generator employing the thermoelectric effects. The simulation results are compared with the experiment to validate the proposed model. It enabled the characterization of WSN nodes comprising different thermoelectric generators and heatsinks in terms of energy conversion efficiency

Heat and Mass Transfer in the Porous Wick of a Capillary Evaporator

Heat and mass transfer inside the porous wick of a capillary evaporator is studied using a mixed pore-network model. The impact of the thermal conductivity of the wick on the overheating limit (defined as the difference between the maximum temperature at the top of the metallic casing and the saturated temperature), breakthrough (which occurs when the vapor reaches the wick inlet) and the parasitic heat flux lost by conduction at the entrance of the wick (which decreases the efficiency of the evaporator) is investigated. The study suggests a bilayer wick as a possible better design to optimize the performance of the evaporator. With this design, the inlet layer is of low thermal conductivity with small pore size so as to reduce the parasitic heat flux. The inlet layer also plays a role of capillary lock limiting the risk of breakthrough. The second layer, right under the metallic casing, is more conductive with a high thermal conductivity and larger pores so as to limit the risk of overheating. It is shown that this design increases the range of heat loads which can be applied to the evaporator.Comment: Proceedings of the 5th International Conference on Porous Media and its Applications in Science and Engineering (ICPM5), June 22-27, 2014, Kona, Hawaii, U

The Sunrise Mission

The first science flight of the balloon-borne \Sunrise telescope took place in June 2009 from ESRANGE (near Kiruna/Sweden) to Somerset Island in northern Canada. We describe the scientific aims and mission concept of the project and give an overview and a description of the various hardware components: the 1-m main telescope with its postfocus science instruments (the UV filter imager SuFI and the imaging vector magnetograph IMaX) and support instruments (image stabilizing and light distribution system ISLiD and correlating wavefront sensor CWS), the optomechanical support structure and the instrument mounting concept, the gondola structure and the power, pointing, and telemetry systems, and the general electronics architecture. We also explain the optimization of the structural and thermal design of the complete payload. The preparations for the science flight are described, including AIV and ground calibration of the instruments. The course of events during the science flight is outlined, up to the recovery activities. Finally, the in-flight performance of the instrumentation is briefly summarized.Comment: 35 pages, 17 figure

Three dimensional heat and mass transfer in capillary evaporator

Heat and mass transfer inside the porous wick of a capillary evaporator is studied using a mixed porenetwork model. The impact of the thermal conductivity of the wick on the overheating limit (defined as the difference between the maximum temperature at the top of the metallic casing and the saturated temperature), breakthrough (which occurs when the vapor reaches the wick inlet) and the parasitic heat flux lost by conduction at the entrance of the wick (which decreases the efficiency of the evaporator) is investigated. The study suggests a bilayer wick as a possible better design to optimize the performance of the evaporator. With this design, the inlet layer is of low thermal conductivity with small pore size so as to reduce the parasitic heat flux. The inlet layer also plays a role of capillary lock limiting the risk of breakthrough. The second layer, right under the metallic casing, is more conductive with a high thermal conductivity and larger pores so as to .limit the risk of overheating. It is shown that this design increases the range of heat loads which can be applied to the evaporator