scholarly journals Numerical Studies on the Performance of the PCM Mesh-Finned Heat Sink Base on Thermal-Flow Multiphysics Coupling Simulation

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4658
Author(s):  
Jiefeng Liu ◽  
Shangxin Yu ◽  
Shichang Yang ◽  
Yiyi Zhang ◽  
Xianhao Fan ◽  
...  
Keyword(s):  
Thermal Management ◽  
Thermal Performance ◽  
Heat Sink ◽  
Coupling Model ◽  
Stable Operation ◽  
Power Losses ◽  
Numerical Studies ◽  
Calculation Results ◽  
Multiphysics Coupling ◽  
Good Potential

Operating temperature is an important parameter of thyristors to ensure the stable operation of power electronic devices. Thermal management technology is of great significance for improving the reliability of thyristors. In this study, the performance of a phase change material (PCM) mesh-finned heat sink is investigated for the thermal management of thyristors. A multi-physical coupling model of the PCM mesh-finned heat sink is established to analyze the effects of different power losses, air velocities, heights of fins, and thickness of PCM on the thermal performance of the PCM heat sink. The influence of thermal and flow fields on PCM is considered in this model. Furthermore, the heat sink design is optimized to improve the thermal performance based on the calculation results of thermal network parameters. The results show that the power losses, the air velocity, the height of fins, and the thickness of PCM significantly affect the protection ability of the PCM heat sink. After optimizing the heat sink, the PCM heat sink provides 80 s protection time and 100 s recovery time. The PCM mesh-finned heat sink demonstrated good potential for the thermal management of thyristors.

Thermal Management of Low Profile Applications

2007 ◽  
Author(s):  
Ed Walsh ◽  
Pat Walsh ◽  
Ronan Grimes ◽  
Vanessa Egan
Keyword(s):  
Thermal Management ◽  
Thermal Performance ◽  
Heat Sink ◽  
Optimal Solution ◽  
Battery Life ◽  
Heat Conducting ◽  
Pumping Power ◽  
Low Profile ◽  
Thermal Solution ◽  
Footprint Area

There is an increasing need for low profile thermal management solutions for applications in the range of five to ten watts targeted at portable electronic devices. This need is emerging due to enhanced power dissipation levels in portable electronics. This work focuses upon the optimization of such a solution within certain constraints of profile and footprint area. A number of fan geometries have been investigated where both the inlet and exit rotor angles are varied relative to the heat conducting fins on a heat sink. The ratio of fan diameter to heat sink fin length was also varied. The objective was to determine the optimal solution from a thermal management perspective within defined constraints. The results show good thermal performance for low profile thermal management solutions, and highlight the need to develop the heat sink and fan as an integrated thermal solution rather than in isolation as is the traditional methodology. It is also found that while increasing pumping power generally improves the thermal performance, only small gains are achieved for relatively large pumping power increases. This is important in optimizing portable systems which are powered by limited battery life.

Experimental Characterization of a Carbon Fiber Composite Material Heat Sink in Boiling Heat Transfer Using FC-72

2006 ◽  
Author(s):  
Venugopal Gandikota ◽  
Harish Chengalvala ◽  
Amy S. Fleischer ◽  
G. F. Jones
Keyword(s):  
Heat Transfer ◽  
Composite Material ◽  
Carbon Fiber ◽  
Thermal Management ◽  
Thermal Performance ◽  
Heat Sink ◽  
Heat Fluxes ◽  
Two Phase ◽  
Operating Temperatures ◽  
Power Densities

The on-going trend towards increasing device performance while shrinking device size often results in escalating power densities and high operating temperatures. High operating temperatures may lead to reduced reliability and induced thermal stresses. Therefore, it is necessary to employ new and innovative thermal management techniques to maintain a suitable junction temperature at high power densities. For this reason, there is interest in a variety of liquid cooling techniques. This study analyzes a composite material heat sink. The heat sink consists of a very large number of small cross-section fins fabricated from carbon pitch fibers and epoxy. These carbon pitch fibers have a high thermal conductivity along the length of the fin. It is expected that the longer length will result in more heat transfer surface area and a more effective heat sink. This experimental study characterizes the thermal performance of the carbon-fiber heat sink in a two-phase closed loop thermosyphon using FC-72 as the operating fluid. The influence of heat load, thermosyphon fill volume, and condenser operating temperature on the overall thermal performance is examined. The results of this experiment provide significant insight into the possible implementation and benefits of carbon fiber heat sink technology in two-phase flow leading to significant improvements in thermal management strategies for advanced electronics. The carbon fiber heat sink yielded heat transfer coefficients in the range of 1300-1500 W/m2 K for heat fluxes in the range up to 3.2 W/cm2. Resistances in the range of 0.20 K/W – 0.23 K/W were achieved for the same heat fluxes. Condenser temperature and fill ratio did not show a significant effect on any of the results.

scholarly journals Thermal Performance Evaluation in Gas Turbine Aero Engines Accessory Gearbox

2020 ◽  
Vol 5 (3) ◽  
pp. 21
Author(s):  
Soheil Jafari ◽  
Ahmed Bouchareb ◽  
Theoklis Nikolaidis
Keyword(s):  
Gas Turbine ◽  
Heat Loss ◽  
Thermal Management ◽  
Thermal Performance ◽  
Sliding Friction ◽  
Methodological Approach ◽  
Rolling Friction ◽  
Power Losses ◽  
Thermal Management System ◽  
Aero Engines

This paper presents a methodological approach for mathematical modelling and physics-based analysis of accessory gearbox (AGB) thermal behavior in gas turbine aero engines. The AGB structure, as one of the main sources of heat in gas turbine aero engines, is firstly described and its power losses will be divided into load-dependent and no-load dependent parts. Different mechanisms of heat generation are then identified and formulated to develop a toolbox for calculation of the churning, sliding friction, and rolling friction losses between contact surfaces of the AGB. The developed tool is also capable of calculating the heat loss mechanisms in different elements of the AGB, such as gears, bearings, and seals. The generated model is used to simulate and analyze the AGB thermal performance in the different flight phases in a typical flight mission, where the obtained results are validated against publicly available data. The analysis of the results confirms the effectiveness of the proposed method to estimate the heat loss values in the AGBs of gas turbine aero engines and to predict the thermal loads of the AGB in different flight phases. The developed tool enables the gas turbine thermal management system designers to deal with the generated heats effectively and in an optimal way.

Thermal performance of nano-enriched form-stable PCM implanted in a pin finned wall-less heat sink for thermal management application

2020 ◽  
Vol 226 ◽  
pp. 113466
Author(s):  
Cyril Reuben Raj ◽  
S. Suresh ◽  
Sudharshan Vasudevan ◽  
M. Chandrasekar ◽  
Vivek Kumar Singh ◽  
...  
Keyword(s):  
Thermal Management ◽  
Thermal Performance ◽  
Heat Sink ◽  
Management Application

Thermal and EMI Performance of Composite Plastic Molded Heat Sinks and Hybrid TIM Materials

2014 ◽  
Vol 2014 (1) ◽  
pp. 000222-000228 ◽  
Author(s):  
Alpesh Bhobe ◽  
Herman Chu ◽  
Lynn Comiskey ◽  
Xiangyang Jiao ◽  
Xiao Li
Keyword(s):  
Thermal Management ◽  
Thermal Performance ◽  
Heat Sink ◽  
Heat Sinks ◽  
Thermal Impedance ◽  
Frequency Range ◽  
Reverberation Chamber ◽  
Plastic Materials ◽  
Thermally Conductive ◽  
Electro Magnetic

Heat sinks are widely used in thermal management of electronics. However, it is also well established that a heat sink can couple and radiate electro-magnetic (EM) energy from the same component that it is cooling. As the frequency of these devices continues to increase, it is more crucial to try to suppress the EM radiation at the source. The component suppliers for thermal management and EMI products have been developing materials that are thermally conductive and also have EM absorbing properties. The thermal and EMI material properties of the additives can change the properties of the final material and they may not always be complementary between thermal and EM absorbing behaviors. In this paper, two such hybrid solutions are investigated to understand the thermal and EM absorbing characteristics and interactions. These are: (1) heat sinks made of composite plastic materials; and (2) hybrid RF/thermal interface materials (HRTIMs). For the heat sink study, three heat sinks of the same physical design (40mm square x 8.25mm tall) but with different materials are tested and analyzed. Two of the heat sinks are molded from two different composite plastics (Materials A and B), while the third one is constructed from aluminum and used as the baseline heat sink for comparison. The results presented in Figure 7 show EMI improvement for composite material heat sinks over the traditional aluminum heat sink. Material A provides a broadband reduction of 2–3 dB power whereas Material B heat sink provides significant reduction at lower frequency range of 1–8 GHz. The thermal performance results are plotted in Figure 11 – Figure 14, and the results show that the composite plastic materials are more suitable for applications that have lower power and power density. For the HRTIMs, two different base materials at different thicknesses are investigated and the material details are given in Table 2 . Similar to the heat sink EMI study, Total Radiated Power (TRP) measurements are performed for the HRTIMs in an Electromagnetic Reverberation Chamber in the frequency range of 5–40 GHz show improvement for material TIM 1. The EMI results are plotted in Figure 9 and Figure 10. For thermal performance characterizations, an ASTM D-5470 compliance test stand (Figure 6) is used. The thermal impedance results of these materials are plotted in Figure 15.

Thermal Management of Low Profile Electronic Equipment Using Radial Fans and Heat Sinks

2008 ◽  
Vol 130 (12) ◽  
Author(s):  
Ed Walsh ◽  
Pat Walsh ◽  
Ronan Grimes ◽  
Vanessa Egan
Keyword(s):  
Thermal Management ◽  
Thermal Performance ◽  
Heat Sink ◽  
Optimal Solution ◽  
Heat Conducting ◽  
Pumping Power ◽  
Low Profile ◽  
Thermal Solution ◽  
Footprint Area ◽  
Reduced Power Consumption

There is an increasing need for low profile thermal management solutions for applications in the range of 5–10W, targeted at portable electronic devices. This need is emerging due to enhanced power dissipation levels in portable electronics, such as mobile phones, portable gaming machines, and ultraportable personal computers. This work focuses on the optimization of such a solution within the constraints of the profile and footprint area. A number of fan geometries have been investigated where both the inlet and exit rotor angles are varied relative to the heat conducting fins on a heat sink. The ratio of the fan diameter to the heat sink fin length was also varied. The objective was to determine the optimal solution from a thermal management perspective within the defined constraints. The results show a good thermal performance and highlight the need to develop the heat sink and fan as an integrated thermal solution rather than in isolation as is the traditional methodology. An interesting finding is that the heat transfer scales are in line with turbulent rather than laminar correlations despite the low Reynolds number. It is also found that while increasing the pumping power generally improves the thermal performance, only small gains are achieved for relatively large pumping power increases. This is important in optimizing portable systems where reduced power consumption is a competitive advantage in the marketplace.

Experimental Characterization of a Unique Carbon Fiber Brush Heat Sink in Two-Phase Heat Transfer

2005 ◽  
Author(s):  
Harish Chengalvala ◽  
Amy S. Fleischer ◽  
G. F. Jones
Keyword(s):  
Heat Transfer ◽  
Carbon Fiber ◽  
Thermal Management ◽  
Thermal Performance ◽  
Heat Sink ◽  
Management Strategies ◽  
Liquid Cooling ◽  
Two Phase ◽  
Two Phase Heat Transfer ◽  
Power Densities

The performance enhancements and footprint decreases of advanced electronic devices result in soaring power densities which may in turn lead to elevated operating temperatures. As elevated device temperatures lead to decreased device reliability and increased thermal stresses, it is necessary to employ aggressive thermal management techniques to maintain an acceptable junction temperature at high power densities. For this reason, interest is growing in a variety of liquid cooling techniques This study analyzes an advanced engineered-material heat sink which provides significant improvements in thermal management strategies for advanced electronics. The heat sink consists of a very large number of small cross-section fins fabricated from carbon pitch fibers. For these carbon pitch fibers, the high thermal conductivity reduces the temperature drop along the length of the fin creating a longer effective fin length than for copper fins. The longer length results in more heat transfer surface area and a more effective heat sink. In liquid cooling, the rough surface of the fin will provide multiple bubble nucleation sites, strongly promoting active two-phase heat transfer over the entire fin surface. This surface enhancement is expected to lead to significant increases in performance over conventional heat sinks. This experimental analysis characterizes the thermal performance of the carbon-fiber heat sink in two-phase closed loop thermosyphon operation using FC72 as the operating fluid. The influence of power load, thermosyphon fill volume and condenser operating temperature on the overall thermal performance is examined. The results of this experiment provide significant insight into the possible implementation and benefits of carbon fiber heat sink technology in two-phase flow leading to significant improvements in thermal management strategies for advanced electronics.

NUMERICAL ANALYSIS OF THE THERMAL PERFORMANCE OF A NOVEL DOUBLE-LAYERED HEAT SINK WITH STAGGERED PIN FINS

2019 ◽  
Vol 50 (8) ◽  
pp. 757-772 ◽  
Author(s):  
Yicang Huang ◽  
Hui Li ◽  
Shengnan Shen ◽  
Yongbo Xue ◽  
Mingliang Xu ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Thermal Performance ◽  
Heat Sink ◽  
Pin Fins
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