Heat Spreading Analysis of a Heat Sink Base Embedded With a Heat Pipe

2005 ◽  
Author(s):  
Brian V. Borgmeyer ◽  
H. B. Ma
Keyword(s):  
Heat Transfer ◽  
Heat Pipe ◽  
Heat Sink ◽  
Heat Transfer Performance ◽  
Convection Heat Transfer ◽  
Transfer Performance ◽  
Uniform Temperature ◽  
Convection Heat Transfer Coefficient ◽  
Flat Heat Pipe ◽  
Heat Spreading

A simplified theoretical model predicting the heat transfer performance of a heat sink base embedded with a flat heat pipe is developed. Numerical analysis was performed using the commercial software FLUENT. The investigation indicates that for heat sink bases 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. The prediction is compared with the experimental data obtained previously.

Study on Periodic Thermal-Switching Behavior of Flat Heat Pipe

2015 ◽  
Author(s):  
Shigeki Hirasawa ◽  
Tatsuya Nakamu ◽  
Tsuyoshi Kawanami ◽  
Katsuaki Shirai
Keyword(s):  
Heat Transfer ◽  
Heat Source ◽  
Heat Pipe ◽  
Heat Transfer Performance ◽  
Switching Behavior ◽  
Transfer Performance ◽  
Unsteady Heat Transfer ◽  
Cold Energy ◽  
Thermal Switching ◽  
Flat Heat Pipe

The coupling of the electrocaloric effect in thin films with thermal switches has the potential to be used for efficient refrigeration. We studied the unsteady heat transfer performance and periodic thermal-switching behavior of a flat heat pipe to transfer cold energy from a changing heat source. The condenser of the flat heat pipe was the changing heat source and changed from −20 W to +20 W every 5 s. The temperature of the condenser surface changed in accordance with the heat generation of the heat source. The evaporator was a plate with a mesh wick attached to a water-flow pipe. Cold energy transferred from the condenser surface to the evaporator surface only when the temperature of the condenser surface was lower than that of the evaporator surface. We analyzed the unsteady temperature change and heat transfer performance of the flat heat pipe by numerical simulation. The analytical results showed that it was necessary to have two thermal switches to separate the heat energy and cold energy of the changing heat source. Also, it was important to reduce the thermal resistance and heat capacity of the evaporator surface to improve the unsteady heat transfer performance of the heat pipe. Next, we measured the unsteady heat transfer performance of the flat heat pipe experimentally. The experimental results showed that the thermal-switching behavior was observed when the heat generation of the heat source changed every 5 s.

A Study on Improving in Natural Convection Heat Transfer for Heat Sink of High Power LEDs

2011 ◽  
Vol 383-390 ◽  
pp. 6834-6839 ◽  
Author(s):  
Xiang Rui Meng ◽  
Xin Ling Ma ◽  
Ji Fu Lu ◽  
Xin Li Wei
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Heat Sink ◽  
Heat Transfer Performance ◽  
Convection Heat Transfer ◽  
Natural Convection Heat Transfer ◽  
Transfer Performance ◽  
Stagnation Zone ◽  
Convection Heat ◽  
Symmetry Center

In this paper the natural convection heat transfer performance of horizontal heat sink was studied by numerical simulation and experiment. The numerical simulation results show that there are some interesting features in the flow field of heat sink model. 1) Among the fins, the air vertically flows only through the fins in the symmetry center of heat sink while it horizontally flows through the fins in other area. 2) There is an air stagnation zone located at the fin root in the symmetry center of heat sink. These features both caused the decrease in heat transfer temperature difference and heat transfer area in fact. The natural convection heat transfer performance of heat sink is affected at last. In order to eliminate the air stagnation zone and change in the flow way of air, some holes were perforated at the fin root. These holes play its role. In this test, the heat transfer power of heat sink with seven holes has increased by 16.7% compared with the prototype.With the increase in the number of holes, the natural convection heat transfer power of heat sink also increases. But when the number of holes reaches to a value, the increase in the number of holes will not function properly.

Experimental Study on Heat Transfer Performance of Pulsating Heat Pipe CPU Radiator

2019 ◽  
Author(s):  
Fu-Min Shang ◽  
Qing-Jing Yang ◽  
Jian-Hong Liu
Keyword(s):  
Heat Transfer ◽  
Heat Pipe ◽  
Wall Temperature ◽  
Heat Sink ◽  
Heat Dissipation ◽  
Heat Transfer Performance ◽  
Structural Characteristics ◽  
Hot Water ◽  
Transfer Performance ◽  
Pulsating Heat Pipe

Abstract According to the characteristics of heat dissipation process and the structural characteristics of traditional heat dissipation device, pulsating heat pipe (PHP) and traditional The pin-finned heat sink are used to simulate the cooling process of CPU, so as to meet the cooling requirements of computer CPU. By comparing the heat transfer perform of the two heat sinks under three conditions: the top wall temperature of the heat sink, the wall temperature of the heat sink and the temperature difference between the inlet and outlet of hot water, it can be found that the heat transfer performance of the PHP radiator is better. The experimental results show that in order to further improve the heat dissipation performance of the computer CPU, the CPU radiator device can be manufactured by the PHP device, and the PHP technology has broad application prospects in electronic heat dissipation.

Enhanced single-phase heat transfer performance via vortex secondary flow in hypervapotron configuration

2021 ◽  
Author(s):  
Ji Hwan Lim ◽  
Minkyu Park
Keyword(s):  
Heat Transfer ◽  
Forced Convection ◽  
Heat Sink ◽  
Single Phase ◽  
Heat Transfer Performance ◽  
Convection Heat Transfer ◽  
Transfer Performance ◽  
Convection Heat ◽  
Forced Convection Heat Transfer ◽  
Power Generation System

Abstract As the hypervapotron (HV) heat sink is used to cool many areas inside the fusion tokamak, it is essential to understand its heat transfer performance to calculate the thermal efficiency of the power generation system. Therefore, in this study, the single-phase (SP) heat transfer performance of HV heat sink was evaluated through sub-cooled flow boiling experiments under one-side high-heat load conditions. When vapor is generated inside the heat sink, flow instability and a potential risk of reaching the critical heat flux are created. Therefore, in commercial power plants, cooling systems tend to operate in the SP regime. System parameters that can be adjusted in the power generation system include the system pressure, mass flow rate, and subcooling, and the effect of these three parameters on the heat transfer performance in the SP regime was analyzed. It was experimentally observed that the mass flow rate was the most influential variable. The prediction performance of the SP forced convection heat transfer correlations of the existing conventiaonl channel were evaluated. The results revealed that they tended to under-predict the heat transfer performance of the HV heat sink. In addition, the same trends were found when the forced convection heat transfer correlation of the curved channel was evaluated. The reasons for the former and the latter are that the heat transfer enhancement effect by the vortex flow occurring between the fins of the HV heat sink is not reflected in the correlations, and the vortex effect of the HV heat sink is not expressed as a variable. Therefore, a new vortex forced convection heat transfer correlation was developed through the newly defined Dean number of the HV heat sink. The developed correlation recorded an average error rate of 0.48%.

The Enhancement Ratio of Corresponding Convection Heat Transfer Coefficient Using Electrospray Evaporative Cooling System

2009 ◽  
Author(s):  
H. C. Wang ◽  
C. P. Hsu ◽  
A. V. Mamishev
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Thermal Management ◽  
Heat Transfer Performance ◽  
Convection Heat Transfer ◽  
Heat Removal ◽  
Transfer Performance ◽  
Enhancement Ratio ◽  
Convection Heat ◽  
Convection Heat Transfer Coefficient

The thermal management of microelectronics demands high heat flux removal solutions due to a rapid increase in component and heat flux densities generated from the integrated circuits (ICs) per unit area. Electrospray evaporative cooling (ESEC), which combines two-phase cooling and an electrospray technique, is presented to be the thermal management solution for next generation microelectronics in order to overcome the heat transfer cooling limits for traditional cooling technologies. In this paper, the enhancement ratio of the corresponding convection heat transfer coefficients and heat removal ability of the ESEC system are investigated in terms of the number of spraying nozzles, total volume flow rates of ethanol alcohol, DC potentials, and gaps between the spraying nozzle and a thermal exchange surface. As the results show, thermal images have indicated the cooling ability of the ESEC system. Additionally, the electrospray modes induced by the distribution of electrostatic fields have a great impact on the heat transfer performance of the ESEC system. The maximum enhancement ratio, 1.61, and heat removal ratio, 61%, has been achieved by the 4-nozzle array. The corresponding calculated heat flux difference and convection heat transfer coefficient were approximately 123.19 W/cm2 and 3.99 W/cm2K, respectively. Furthermore, the results also indicate that increase the number of the spraying nozzle and decrease the flow rate per nozzle is regarded as the effective way of improving the heat transfer performance of ESEC devices. A simple regression curve for the relationship between the heat removal ratio and enhancement ratio was also addressed.

scholarly journals 3D printed aluminum flat heat pipes with micro grooves for efficient thermal management of high power LEDs

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chao Chang ◽  
Zhaoyang Han ◽  
Xiaoyu He ◽  
Zongyu Wang ◽  
Yulong Ji
Keyword(s):  
Heat Transfer ◽  
Heat Pipe ◽  
Thermal Management ◽  
Aluminum Powder ◽  
Heat Transfer Performance ◽  
Filling Ratio ◽  
Working Fluid ◽  
Transfer Performance ◽  
3D Printed ◽  
Flat Heat Pipe

AbstractAs the electronic technology becomes increasingly integrated and miniaturized, thermal management has become a major challenge for electronic device applications. A heat pipe is a highly efficient two-phase heat transfer device. Due to its simple structure, high thermal conductivity and good temperature uniformity, it has been used in many different industrial fields. A novel aluminum flat heat pipe, with micro-grooves, has in the present work been designed and fabricated by using a 3D printing technology. Aluminum powder was used as a raw material, which was selectively melted and solidified to form the shape of the heat pipe. The sintered aluminum powder increased the roughness of the inner surface of the heat pipe, and the designed micro-grooves further enhanced the capillary forces induced by the wick structure. The wettability, for the working fluid (acetone), was excellent and the capillary forces were sufficient for the working fluid to flow back in the pipe. The effects of working fluid filling ratio, on the heat transfer performance of the heat pipe, was also investigated. It was shown that a filling ratio of 10% gave the best heat transfer performance with the lowest thermal resistance. The 3D-printed flat heat pipe was, therefore, also tested for the thermal management of a LED. The temperature of the LED could be kept within 40 °C and its service life became prolonged.

scholarly journals Testing algorithm for heat transfer performance of nanofluid-filled heat pipe based on neural network

Open Physics ◽  
2020 ◽  
Vol 18 (1) ◽  
pp. 751-760
Author(s):  
Lei Lei
Keyword(s):  
Neural Network ◽  
Heat Transfer ◽  
Heat Pipe ◽  
Heat Transfer Performance ◽  
Volume Fraction ◽  
Heat Pipes ◽  
Transfer Performance ◽  
Analysis Model ◽  
Accurate Analysis ◽  
Testing Algorithm

AbstractTraditional testing algorithm based on pattern matching is impossible to effectively analyze the heat transfer performance of heat pipes filled with different concentrations of nanofluids, so the testing algorithm for heat transfer performance of a nanofluidic heat pipe based on neural network is proposed. Nanofluids are obtained by weighing, preparing, stirring, standing and shaking using dichotomy. Based on this, the heat transfer performance analysis model of the nanofluidic heat pipe based on artificial neural network is constructed, which is applied to the analysis of heat transfer performance of nanofluidic heat pipes to achieve accurate analysis. The experimental results show that the proposed algorithm can effectively analyze the heat transfer performance of heat pipes under different concentrations of nanofluids, and the heat transfer performance of heat pipes is best when the volume fraction of nanofluids is 0.15%.

Sign in / Sign up

Export Citation Format

Share Document