Electronics cooling

About: Electronics cooling is a research topic. Over the lifetime, 1135 publications have been published within this topic receiving 17608 citations.

An Experimental and Computational Heat Transfer Study of Pulsating Jets

Abstract: Synthetic jets are meso or microscale fluidic devices, which operate on the "zero-net-mass-flux" principle. However, they impart a positive net momentum flux to the external environment and are able to produce the cooling effect of a fan sans its ducting, reliability issues, and oversized dimensions. The rate of heat removal from the thermal source is expected to depend on the location, orientation, strength, and shape of the jet. In the current study, we investigate the impact of jet location and orientation on the cooling performance via time-dependent numerical simulations and verify the same with experimental results. We firstly present the experimental study along with the findings. Secondly, we present the numerical models/results, which are compared with the experiments to gain the confidence in the computational methodology. Finally, a sensitivity evaluation has been performed by altering the position and alignment of the jet with respect to the heated surface. Two prime orientations of the jet have been considered, namely, perpendicular and cross jet impingement on the heater. It is found that if jet is placed at an optimum location in either impingement or cross flow position, it can provide similar enhancements.

Applying heat transfer coefficient data to electronics cooling

Abstract: Many electronics cooling applications involve direct air cooling of the components and their heat transfer performance is often estimated, in teh design phase, using heat transfer coefficient data from either in-house data or published sources. The agreement between predicted and observed system performance is quite often not acceptable, which means that the cooling system must be developed empirically - an expensive and time-consuming process. The authors believe they have identified one important reason for this state of affairs: the heat transfer coefficient values presented in the literature are being used improperly. Almost all of the published heat transfer coefficient data are from single-active-component experiments, which implicitly define h based on the adiabatic temperature of the component (h{sub ad}), while most users assume h to be defined on the basis of the mean fluid temperature (h{sub m}). This misunderstanding lead to underpredictions of the temperature rise of the components by 20-30% or more. This paper reviews the options for defining the heat transfer coefficient, shows how the problem arises, and then describes the steps necessary to properly use the existing heat transfer coefficient data base. There are two options for applying the existing data base to a fully powered array: Onemore » can either calculate the adiabatic temperature of the components from the known heat release distribution in the array or calculate the values of h{sub m} that can be used to T{sub m}, again using the known heat release distribution. The two options represent different ways to apply the same general method, superposition. The superposition method of Sellars, et al., (1956) is adapted to discrete systems and used as a guide to the forms recommended.« less

Applying heat transfer coefficient data to electronics cooling

Abstract: This paper reviews the options for defining the heat transfer coefficient, shows how the problem arises, and then describes the steps necessary to properly use the existing heat transfer coefficient data base. There are two options for applying the existing data base to a fully powered array: One can either calculate the adiabatic temperatures of the components from the known heat release distribution in the array or calculate the values of h m that can be used with T m , again using the known heat release distribution

Thermal Measurements in Electronics Cooling

Abstract: Electronics Cooling and the Need for Experimentation, K. Azar Uncertainty Analysis, R.J. Moffatt Similitude in Electronics Cooling, M.T. Boyle Measuring Velocity in Electronics Systems, J. Foss, C. Wark, and D. Williams Temperature Measurement in Electronics Cooling, J. Sweet Measuring Pressure in Electronics Systems, G.A. Pender Measuring Thermal Conductivity and Diffusivity, J.E. Graebner Heat Flux Measurements: Theory and Applications, N.R. Keltner Wind Tunnel Design, R.V. Westphal Flow Visualization Methods and their Application in Electronics Systems, S.V. Garimella Principles of Component Characterization, J.W. Sofia Acoustical Noise Measurement and Control in Electronics Systems, G.C. Maling and D.M. Yeager Index

Advances in Electronics Cooling

Abstract: This article highlights the advantages of on-chip microchannel cooling technology, based on first- and second-law analysis and experimental tests on two types of cooling cycles, the first driven by an oil-free liquid pump and the second by an oil-free vapor compressor. The analysis showed that the drivers of the fluid were the main culprits for major losses. It was further found that when energy recovery is of importance, making use of a vapor compression cycle increases the quality of the recovered energy, hence increasing its value. This was demonstrated by analyzing the synergy that can exist between the waste heat of a data center and heat reuse by a coal-fired power plant. It was found that power-plant efficiencies can be increased by up to 6.5% by making use of a vapor compression cycle, which results not only in significant monetary savings, but also in the reduced overall carbon footprints of both the data center and the power plant.