Energy Efficiency of Low Form Factor Cooling Devices

2010 12th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems

2010

Self Cite

Many novel thermal management technologies have been developed to ameliorate the losses from modern electronics. As these techniques are developed, designers endeavor to compare each method with existing concepts. However, many of these comparative metrics can be system-dependent, leading to inconclusive results. One of the most common metrics, the thermal resistance, is a simple relationship between the total heat transfer from a device and its temperature rise above a reference condition. However, the thermal resistance metric has several issues that can limit its utility in comparing systems, particularly due to its dimensional nature and consequent dependence on system size. In addition, this metric does not include any information about the amount of power required for cooling a system. To improve comparisons, a non-dimensional volumetric coefficient of performance is proposed, accounting for issues such as thermal performance, system extent, and input power requirement. This new parameter is compared with other common metrics in the examination of two promising contemporary cooling solutions: synthetic jet air cooling and microchannel liquid cooling.

Section: Synthetic Jetsmentioning

confidence: 93%

“…Note that another potential nondimensionalization would use the masses of the cooling system and the devices, a comparison that may have greater utility in applications where weight is a concern. Piezo-fans [5] 100 ~10 Spray impingement [15] 10000 ~30…”

Section: Effective Coefficient Of Performancementioning

confidence: 99%

Understanding the performance metrics for advanced cooling methodologies

Solovitz

2010 12th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems

2010

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“…Technologies such as smallscale rotary fans [2], piezo fans [3], ionic winds [4], and synthetic jets [5] are of interest over the last decade. Our research has been focused on heat transfer demonstration of synthetic jets in natural convection, and a number of papers have been published [5,6,7,14]. In the present study, we turn our attention to understanding forced convection cooling coupled with synthetic jet flow.…”

Section: Introductionmentioning

confidence: 98%

“…A detailed discussion of the energy efficiency, cooling performance and acoustic issues are given in [6]. It is pointed out that design of a synthetic jet should be well coupled with the system to obtain the optimized performance.…”

Section: Introductionmentioning

confidence: 99%

Augmenting forced convection heat transfer coupled with an aerodynamic surface and a synthetic jet

Salapakkam

2010 12th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems

et al. 2010

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Forced convection heat transfer is limited with the fan flow rate or pressure drop. Therefore, it is necessary to develop novel cooling technologies that can enhance forced convection. A new heat sink design is proposed for electronics cooling applications. The objective of this study was to develop a new heat sink design, which increases heat transfer properties while containing the pressure drop. Twodimensional CFD analysis was used to optimize the shape of the heat sink. Enhancing the heat transfer characteristics also increased the pressure drop and hence the fan power. It is observed that lower heat sink surface temperatures are highly non-linear and produce significantly larger pressure drops. A new aerodynamic heat sink shape is proposed by integrating aerodynamic flow characteristics and fan performance curves. The results show that a good compromise for higher heat transfer properties while marginally increasing the pressure drop is possible. However, we believe that further optimization of this technology will enable lower thermal resistance at the same pressure drop compared to baseline forced convection in the same flow rate.

“…The board resistance is very sensitive to components and materials, so the ones with low conductivity cause thermal efficiency to be very low and have a significant impact on the performance. 2,3 A good design of the board must take thermal management into account. In the design process, there is a limitation on LED junction temperature, and the light intensity has an inverse relationship with chip temperature.…”

Section: Introductionmentioning

confidence: 99%

Conduction-driven cooling of LED-based automotive LED lighting systems for abating local hot spots

Saati¹,

2018

Opt. Eng.

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Abstract. Light-emitting diode (LED)-based automotive lighting systems pose unique challenges, such as dualside packaging (front side for LEDs and back side for driver electronics circuit), size, harsh ambient, and cooling. Packaging for automotive lighting applications combining the advanced printed circuit board (PCB) technology with a multifunctional LED-based board is investigated with a focus on the effect of thermal conduction-based cooling for hot spot abatement. A baseline study with a flame retardant 4 technology, commonly known as FR4 PCB, is first compared with a metal-core PCB technology, both experimentally and computationally. The doublesided advanced PCB that houses both electronics and LEDs is then investigated computationally and experimentally compared with the baseline FR4 PCB. Computational models are first developed with a commercial computational fluid dynamics software and are followed by an advanced PCB technology based on embedded heat pipes, which is computationally and experimentally studied. Then, attention is turned to studying different heat pipe orientations and heat pipe placements on the board. Results show that conventional FR4-based light engines experience local hot spots (ΔT > 50°C) while advanced PCB technology based on heat pipes and thermal spreaders eliminates these local hot spots (ΔT < 10°C), leading to a higher lumen extraction with improved reliability. Finally, possible design options are presented with embedded heat pipe structures that further improve the PCB performance.