Heat Dissipation Technology Research Articles

Dominant Role of Surface Peak-Valley Features in Droplet Infiltration Dynamics.

In this study, droplet infiltration dynamics on microtextured surfaces is explored to demonstrate the dominant role of surface peak-valley features in the capillary-driven wetting process. Even though two rough surfaces have nearly the same roughness, the microtopography and distribution of surface peaks and valleys may be completely different, leading to variations in liquid infiltration characteristics. Experimental results show that under the same surface roughness (Sa = 12.0 μm), the positively skewed surface dominated by micropillars (Ssk > 0) is more conducive to liquid infiltration compared with the negatively skewed surface dominated by micropits (Ssk < 0). The physical mechanism is fully analyzed in terms of the equilibrium of the air-liquid interface by constructing a hydrodynamic model. This study also demonstrates that the dominant influence of surface peak-valley features on droplet infiltrating dynamics is independent of the materials. Moreover, the cooling efficiency of the prepared surfaces is compared, and the results indicate that the micropillar surfaces with positive skewness exhibit superior heat dissipation performance under similar conditions because of their excellent infiltration features and large spreading area, proving that positively skewed surfaces have high utilization potential in high-density heat dissipation technology.

Effect of the Surface Peak-Valley Features on Droplet Impact Dynamics under Leidenfrost Temperature.

This study explores the kinetic behavior of droplets impacting microtextured surfaces under a Leidenfrost temperature, employing high-speed photography and picosecond laser micromachining techniques. The investigation focuses on two types of microtextured surfaces with totally different surface peak-valley features: a negatively skewed surface with micropit arrays (Ssk < 0) and a positively skewed surface with micropillar arrays (Ssk > 0). The results indicate that both microtextured surfaces contribute to a higher Leidenfrost temperature compared with the original smooth surface, which is consistent with previous studies. However, it is worth noting that the Leidenfrost points of the micropit and micropillar surfaces showed opposite trends with the microtexture area occupancy. Specifically, the Leidenfrost temperature on micropit surfaces increases with greater micropit area occupancy, while it decreases on micropillar surfaces under similar conditions, which is mainly attributed to the differential impact of area occupancy on droplet heat transfer efficiency. When the microtexture area occupancy is 50%, it is worth noting that the micropit and micropillar surfaces have nearly same roughness (Sa), but the Leidenfrost temperature was notably higher on the micropit surface with negative skewness (Ssk < 0), which was related to differences in vapor flow dynamics. We further find that the Weber number (We) significantly influences the Leidenfrost point, with the droplet impact wall behavior going through the states of film bounce back, ejecting tiny droplets and bounce back, and ultimately droplet breakup as the We increases. The dynamic Leidenfrost point was found to be generally higher than the static point and increases with the We. Finally, we compare the cooling efficiency of these surfaces, and it is found that the micropit surfaces with a negative skewness exhibit superior heat dissipation performance under the same conditions, which proved that the negatively skewed surface may have great potential in high-density heat dissipation technology.

Thermally enhanced flexible phase change materials for thermal energy conversion and management of wearable electronics

The developing trend of miniaturization and integration for electronics imposes challenges of efficient heat dissipation technology, where novel materials with advanced thermal energy conversion and management are urgently needed. In this work, we propose an emerging phase change material (PCM) system with polyvinyl alcohol/expanded graphite network loading paraffin wax (PE-PW), which exhibits superb flexibility, thermal energy storage capacity and thermal conductivity. The phase change enthalpy is from 115.61 J/g to 168.93 J/g without any leakage, which can be maintained even after 500 thermal cycles. The thermal conductivity can reach 1.46 W/mK, 484% enhanced compared with that of pure PCM. Meanwhile, the thermal management test indicates that the PE-PW composites can quickly absorb and store the generated heat to achieve temperature control, thus protecting the system from overheating and indicating excellent thermal management capacity. This flexible PE-PW system has broad application prospects in the field of thermal energy conversion and management for wearable electronics.

Statics Performance and Heat Dissipation Evaluation of Lattice Structures Prepared by Laser Powder Bed Fusion.

This paper address the performance optimization of the battery heat sink module by analyzing the lattice structure of the battery heat sink module through in-depth modeling and simulation, and combining the laser powder bed fusion (LPBF)-forming technology with mechanical and corrosion resistance experiments for a comprehensive study. It is found that the introduction of the lattice skeleton significantly improves the thermal conductivity of the phase change material (PCM), realizing the efficient distribution and fast transfer of heat in the system. At the same time, the lattice skeleton makes the heat distribution in the heat exchanger more uniform, improves the utilization rate of the PCM, and helps to maintain the stability of the cell temperature. In addition, the melting of PCM in the lattice heat exchanger is more uniform, thus maximizing its latent heat capacity. In summary, by optimizing the lattice structure and introducing the lattice skeleton, this study successfully improves the performance of the battery heat dissipation system, which provides a strong guarantee for the high efficiency and stable operation of the battery, and provides new ideas and references for the development of the battery heat dissipation technology.

Design and research of heat dissipation system of electric vehicle lithium-ion battery pack based on artificial intelligence optimization algorithm

This research focuses on the design of heat dissipation system for lithium-ion battery packs of electric vehicles, and adopts artificial intelligence optimization algorithm to improve the heat dissipation efficiency of the system. By integrating genetic algorithms and particle swarm optimization, the research goal is to optimize key design parameters of the cooling system to improve temperature control and extend battery life. In the process of algorithm implementation, genetic algorithm improves the diversity of population through crossover and mutation operations, thus enhancing the global search ability. Particle swarm optimization (PSO) improves local search accuracy and convergence speed by dynamically adjusting inertia weight and learning factor. The effects of different design schemes on heat dissipation performance were systematically evaluated by using computational fluid dynamics (CFD) software. The experimental results show that the efficiency of the cooling system is significantly improved after the application of the optimization algorithm, especially in the aspects of temperature distribution uniformity and maximum temperature reduction. The optimization algorithm also successfully shortens the thermal response time of the system and improves the adaptability and stability of the system under different working conditions. The computational complexity and execution time of these algorithms are also analyzed, which proves the efficiency and feasibility of these algorithms in practical applications. This study demonstrates the practicability and effectiveness of artificial intelligence optimization algorithm in the design of heat dissipation system of lithium-ion battery pack for electric vehicles, and provides valuable reference and practical guidance for the progress of heat dissipation technology of electric vehicles in the future.

Self-driven manifold microchannel heat sink for cooling electronics

The advancement of passive, compact, and lightweight thermal management technology for high-power chips is essential for the stable and efficient operation of the next generation of electronic devices. A novel self-driven heat sink based on embedded manifold microchannel heat dissipation technology is proposed, which uses capillary force as the driving force to replace the pump, and minimize pressure drop and thermal resistance between the heat sink and heat source. This design of the embedded self-driven manifold microchannel heat sink allows for the integration and miniaturization of the heat sink and the chip heat source. Through Micro Electromechanical Systems technology, an experimental sink with microchannels with a high aspect ratio was fabricated. A theoretical model is constructed to analyze the influence of the width and depth of the microchannel on the limit heat flux, and the correctness of the model is verified by experiments. The results indicate that the width has a more significant impact on the limit heat flux compared to the depth. An optimal width of 6.5 μm is identified. As the depth increases, the influence of depth on the limit heat flux diminishes. By conducting theoretical calculations on the embedded self-driven manifold microchannel heat sink, it was determined that the device using HFE7100 as the working fluid demonstrates a wider heat load range than ethanol and acetone, and the limit heat flux can reach 41.5W/cm2.

Investigation of a hybrid two-layered channel-jet heat sink for air cooling

With the miniaturization and deep integration of electronics, the challenges associated with high-power heat dissipation technology have increased. Combining the features of jet cooling technology and microchannel cooling technology, a hybrid two-layered channel-jet heat sink is designed for general consumer CPUs. The heat sink performance is investigated experimentally. Since the CPU generation power is 120 W, the heat sink can control the CPU excess temperature below 60 °C with an air volume less than 20 m3/h and a pressure drop less than 20 Pa. The different geometric parameters of the heat sink are numerically calculated. Increasing the channel width and reducing the channel height and slot length can enhance the heat transfer but also increase the pressure drop. Orthogonal tests are employed to optimize the design by evaluating the performance of various heat sink structures. The performance evaluation criterion (PEC) is selected as the evaluation index. Under standard conditions with a cross-sectional airflow velocity of 1.5 m/s, the optimal structure is a 2 mm channel width, 12 mm channel height and 50 mm slot length.

Liquid metal manifold microchannel heat sink for ultra-high heat flux cooling

Advanced heat dissipation technology is crucial for chip operation and performance utilization. Room temperature liquid metal convection cooling technology has demonstrated its efficacy as a viable approach for addressing high heat flux heat dissipation. However, the smaller specific heat capacity of liquid metal leads to a large temperature rise, hindering the advancement of its cooling technology. To address this, a liquid metal manifold channel structure is proposed to convert the continuous long-range flow into a segmented short-range flow. The good matching between liquid metal and manifold structures is adequately demonstrated through a comparison with alternative coolant and channel structure. The simulation results demonstrate the effectiveness of liquid metal manifold channel cooling in dealing with a heat flux of 1000 W/cm2, ensuring that the maximum temperature of the chip remains below 351.7 K. Moreover, the convective heat transfer coefficient even reaches 106 W/(m2·K), which is ten times larger than that of water conventional microchannel heat sink. Orthogonal experiments analyzed the impact of structural parameters on dissipation performance, including the height of the microchannel, ratio of manifold length to fin length, length of fin in manifold, width of channel, and ratio of fin with to channel width. The height of the microchannel has been identified as the most critical factor. This manifold structure mitigates the inherent limitation of liquid metal's lower specific heat capacity, enabling efficient thermal management for electronic devices under ultra-high heat flux conditions.

Research Status of Heat Dissipation Technology for Electric Vehicle Drive Motors

Background:: The application of electric vehicles in daily life is becoming increasingly widespread. However, the heat dissipation issues of the electric motors directly impact electric vehicles' stability and safety. Thus, research on the heat dissipation of the electric motor is conducive to improving the reliability of the drive motor and ensuring the overall stability and safety of electric vehicles; there is a growing emphasis on the development trends of heat dissipation technologies for electric vehicle drive motors. Objective:: In order to meet the increasing requirements of electric vehicles for stability and safety and to solve the problems of low heat dissipation efficiency of electric vehicle drive motors, the size of heat dissipation devices, and the short life span caused by the high temperature of drive motors, the heat dissipation of drive motors is optimized and the heat dissipation structure is improved. Methods:: Based on the structural characteristics of heat dissipation of electric vehicle drive motors, various representative patents related to the current heat dissipation technology of electric vehicle drive motors are summarized. Results:: By summarizing a large number of patents on electric vehicle drive motor heat dissipation technology, it is concluded that the current research on electric vehicle drive motor heat dissipation mainly focuses on liquid heat dissipation or gas heat dissipation and that the main reason for the heat dissipation problem of electric vehicle drive motors is the low heat dissipation efficiency due to over-reliance on a single heat dissipation method, and the reliability is poor due to failure to reasonably control heat dissipation according to the need for heat dissipation. This paper proposes a new idea of heat dissipation for electric vehicle drive motors, which effectively combines liquid heat dissipation and gas heat dissipation. Moreover, the heat dissipation efficiency will be significantly higher than the existing heat dissipation scheme, and the proposed heat dissipation concept of "ondemand distribution" will effectively improve the utilization rate of the heat dissipation medium and reduce the heat dissipation cost and the reasonable heat dissipation structure will reduce the volume of the heat dissipation device. The reasonable heat dissipation structure will also reduce the volume of the heat dissipation device. In addition, the future development of heat dissipation technology for electric vehicle drive motors is also discussed. Conclusion:: The heat dissipation scheme proposed in this paper will effectively improve the heat dissipation problem of electric vehicle drive motors. Compared with the existing heat dissipation methods, the heat dissipation efficiency of the heat dissipation scheme proposed in this paper will be improved by more than 8.5%, and the service life of the drive motor will be extended by more than 5.1%, while the size of the electric vehicle drive motor will be reduced by 6%. More related patents will be invented in the future.

Experimental measurement of a multi-pole magnetorheological fluid clutch under air cooling.

Thermal characteristics have a profound effect on the allowable slip power and torque transmission stability of magnetorheological (MR) fluid devices. This paper investigates the thermal properties of a multi-pole MR clutch under different heat dissipation methods. First, the structure of the clutch is described, and heat generation and heat dissipation of the designed clutch are studied theoretically. Then, a numerical model is established, and several simulations are conducted on steady-state and transient temperatures under various operation conditions. After that, a temperature testing platform for the MR clutch is built, and several temperature experiments are carried out. The results show that the allowable steady-state slip power of the clutch under natural air cooling is about 147W. Under forced air cooling, the allowable steady-state slip powers are 1.295, 1.555, and 1.790 kW, respectively, when the wind speeds are 3.5, 7.0, and 10.5m/s. Furthermore, it turned out that the transmission torque of the MR clutch decreases with the increase in temperature. The experimental and simulated values of temperature are in good agreement in terms of numerical values and trends, indicating that the established temperature field simulation model can better reflect the temperature characteristics of the actual operation of the proposed multi-pole MR clutch. This research achievement can provide support for research on heat dissipation technology for MR devices with multiple excitation sources.

Ultra-thin vapour chamber based heat dissipation technology for lithium-ion battery

A powerful thermal management scheme is the key to realizing the extremely fast charging of battery electric vehicles. In this scheme, a water-cooled plate is set at the bottom of the battery modules, which has a remarkable heat dissipation ability but increases the temperature difference between the top and bottom of the battery. This temperature difference problem is more obvious during the high-rate charge/discharge process; in particular, in the area of battery tabs, which are usually located far from the cooling plate, heat accumulates, risking thermal runaway. To address this problem, a thermal management method based on an ultrathin vapour chamber (UTVC) is proposed in this paper to improve temperature uniformity and reduce the highest temperature of batteries. According to the number of applied UTVCs, a unilateral UTVC (U-UTVC) and a bilateral UTVC (B-UTVC) cooling approach were presented, the effectiveness of which was verified by a set of thermal performance experiments. The test data show that the temperature differences in the batteries under the U-UTVC and B-UTVC schemes are 39.77% and 73.54% lower than those under the traditional method at a 25 °C ambient temperature and a 1.39C charge rate, respectively. The temperature difference on the battery surface with the B-UTVC scheme is approximately 3 °C at 25 °C and 40 °C ambient temperature.

Molecular dynamics study of boiling heat transfer in nanochannels under capillary flow

The increasing heat flux of electronic devices poses significant challenges in thermal management. Passive heat dissipation technology based on capillary drive has been widely concerned because it does not require external driving force and stability. However, due to the small size of the internal capillary structure, typically in the micro and nano scales, and the significant scale effect, further research is needed to understand the mechanism of internal boiling heat transfer. This study systematically investigates the boiling process of liquid in nanochannels under capillary flow with varying wettability using molecular dynamics simulations. It is found that increasing the energy coefficient (c) causes a greater accumulation of atoms near the wall, thereby enhancing the efficiency of solid–liquid heat transfer. The bubble has a larger stable volume as c increases and will burst in the case of high c. As c increases, the region of high potential and kinetic energy expands more rapidly, reducing the time it takes for bubble nucleation and rupture. The behavior of bubbles is significantly influenced by capillary flow, which is also influenced by wettability. When c = 0.9, the flow velocity reaches its maximum before bubble nucleation occurs. It leads to a more homogeneous heat transfer, resulting in a higher location of bubble nucleation. Furthermore, the presence of capillary forces increases the average potential energy of surrounding liquid atoms, thereby enhancing the growth rate of the bubble. This study provides a theoretical basis for the optimal design of capillary-driven two-phase heat dissipation devices.

&lt;i&gt;x&lt;/i&gt;Fe/Bi&lt;sub&gt;0.5&lt;/sub&gt;Sb&lt;sub&gt;1.5&lt;/sub&gt;Te&lt;sub&gt;3&lt;/sub&gt; thermoelectromagnetic films with coexistence of positive and negative magnetoresistance

Thermoelectric (TE) films with excellent electrical transport property are key materials for developing efficient in-plane heat dissipation technology, but their low electrical transport property is a challenge that restricts their application. Recently, a new thermo-electro-magnetic coupling effect has been proposed to significantly improve the comprehensive TE performance. In order to explore the influence of the above effects on the electric transport property of TE films, we develop an integrated preparation method through ball milling dispersion, screen-printing and hot-pressing curing, obtaining a series of &lt;i&gt;x&lt;/i&gt;Fe/Bi&lt;sub&gt;0.5&lt;/sub&gt;Sb&lt;sub&gt;1.5&lt;/sub&gt;Te&lt;sub&gt;3&lt;/sub&gt; (BST)/epoxy TE films in which Fe nanoparticles serve as the second phase, resulting in the thermo-electro-magnetic coupling effect , and also we study their influence on the electrothermal transport performance. The results are shown below. The positive and negative magnetoresistance are co-existent in &lt;i&gt;x&lt;/i&gt;Fe/BST/epoxy thermoelectromagnetic films; the preferred orientation factor of BST (000&lt;i&gt;l&lt;/i&gt;) is positively proportional to the positive magnetoresistance (MR&lt;sup&gt;+&lt;/sup&gt;), resulting in an increase of the conductivity; the spin-dependent scattering of negative magnetoresistance (MR&lt;sup&gt;–&lt;/sup&gt;) derived from the local magnetic moment of strong ferromagnetic Fe nanoparticles increases the Seebeck coefficient. Hence, the power factor of Fe/BST/epoxy thermoelectromagnetic film near room temperature reaches 2.87 mW⋅K&lt;sup&gt;–2&lt;/sup&gt;⋅m&lt;sup&gt;–1&lt;/sup&gt;, which is 78% higher than that of BST/epoxy thermoelectric film. These results indicate that the coexistence of positive and negative magnetoresistance in thermoelectromagnetic films can not only relieve the coupling relationship between conductivity and Seebeck coefficient in TE materials, but also provide a new physical mechanism for the excellent TE conversion performance induced by magnetic nanoparticles.

Analysis of factors influencing heat transfer performance based on ship spray cooling system

The increasingly prominent issue of equipment heat dissipation has seriously hindered the further development of ship engineering. The heat exchange of traditional heat dissipation technology is limited, resulting in insufficient heat dissipation capacity and difficulty in meeting the heat dissipation needs of ships. Given these problems, this study constructs to use spray cooling technology to solve the heat dissipation problem of ships, and on this basis, the reason causing the heat transfer performance of R134a spray cooling system are analyzed. As there is lubricating oil in the spray cooling system, this study also partially explores such type of system with lubricating oil. The experimental data validate that when the heat flux densities are 30.0 W/cm2, 45.0 W/cm2, and 55.0 W/cm2, the heat transfer coefficients are 19.23?103 W/m2?), 24.02?103 W/m2?C, and 18.70?103 W/m2?C, respectively, and the surface temperature of the heat source is 29.13?C, 38.21?C, and 48.23?C. When the lubricating oil concentration is fixed at 1.47%, during the process of increasing the heat flux density from 10 W/cm2 to 50 W/cm2, the surface temperature rises from 32.33?C to 55.28?C, and the heat transfer coefficient increases from 7.54?103W/m2?) to 9.46?103W/m2?C. In conclusion, the proposed mass-flow rate, heat flow density, and evaporation chamber pressure have a significant impact on the heat transfer performance of the ship?s spray cooling system, on the contrary, the lubricating oil has a significant impact on the system performance.

Principle, Fabrication and Applications of Micro-Nano Fluid Dynamics

A new generation of efficient heat transfer and cooling technologies has been studied by researchers since the 1990s due to the rise of nanotechnology. In 1995, Professor S.U.S. The idea of 'nanofluids' was first proposed by Choi from the Aragon National Laboratory in the United States, which combines nanotechnology with traditional thermal engineering in an innovative way. Enhanced heat transfer is a field where nanofluid technology has broad application prospects and potential significant economic value, and is known as the 'future cooling and heat dissipation technology'. The theme of this article is the principles, preparation processes, and application fields of micro-nano fluids. The research on nanofluids still needs to be carried out. Due to their unique thermal conductivity properties, they can theoretically be widely used in fields such as industry, energy, aerospace, automobiles, air conditioning and refrigeration, electronics, etc. The aim of this study is to examine the heat conduction principle of nanofluids, the basic preparation process, and some applications of nanofluids in the field of enhanced heat conduction.

Analysis of Heat Dissipation of Lithium Battery Pack Based on Eddy Current Tube

In this study, numerical heat dissipation simulation is carried out using vortex tube heat dissipation technique for the heat dissipation problem of lithium batteries. First of all, the type of lithium battery, thermal runaway phenomenon, thermal runaway temperature range, and then the lithium battery group cooling methods and advantages and disadvantages of the exposition; followed by the working principle of eddy current tube, the application of the way, as well as the advantages and disadvantages of the exposition. Combined with the vortex tube's own structural characteristics, numerical simulation is used to apply the vortex tube cooling to lithium battery heat dissipation. This study provides new ideas and methods for the development of lithium battery heat dissipation technology, and has important reference value for solving the heat dissipation problems of lithium battery in practical applications.

Magnetic ordering boost excellent thermoelectric performance of flexible films

The poor electrical transport performance of flexible thermoelectric (TE) films is a major bottleneck for the development of in-plane heat dissipation technology based on Peltier effect. Herein, ordered Fe nanoparticles (Fe-NPs) and in-situ Fe3O4 nanoparticles (Fe3O4-NPs) as magnetic functional elements (MFEs) were embedded into Bi0·5Sb1·5Te3 (BST)/epoxy flexible films in order to enhance the TE performance. The remarkable increases in electrical conductivity of BST/MFEs/BST/epoxy flexible films have been confirmed to originate from the carrier mobility increases. The retention of large Seebeck coefficient is attributed to the negative magnetoresistance (MR−) induced by spin-dependent scattering and weak localization effect from MFEs. As a result, the maximum power factor of BST/MFEs/BST/epoxy flexible films increased by 45%, and the maximum cooling temperature difference enhanced by 1.6 times. This work reveals that the ordered MFEs can significantly boost the electro-thermal conversion performance of flexible TE films and the magnetoresistance theory can reveal the scattering mechanism of charge carriers in thermo-electromagnetic flexible films.

Controlled synthesis of oxygen-doped rod-shaped boron nitride and its thermal conductivity enhancement properties

In the problem of heat dissipation of electronic materials, the traditional heat dissipation technology cannot meet the current demand. The existing liquid-cooled thermal fluid has poor thermal conductivity, which limits its application. Among the methods to improve the thermal conductivity of nanofluids, selecting materials with high thermal conductivity as dispersants is a very effective method. Herein, we report the preparation of an oxygen-doped rod-shaped boron nitride (BN–O). Oxygen-doped rod-shaped boron nitride has a suitable aspect ratio to form an effective thermal conductivity network, which effectively improves the thermal conductivity of the matrix material. In addition, the hydroxyl groups formed after functionalization of the BN-O hydroxyl groups, can form van der Waals forces between the molecules of the water-ethylene glycol solution. This allows the thermally conductive filler to be stably present in the matrix material, thereby increasing the thermal conductivity. Thus BN-O has good thermal conductivity and dispersion, while the morphology of BN-O is regulated by the boron-to-nitrogen ratio of the reactants. Under the same reaction conditions, the BN has a rod-shaped morphology for a boron-to-nitrogen ratio close to 1. Notably, the test results show that the thermal conductivity of the water-ethylene glycol matrix is 0.43W/m·K. After adding the same amount of BN-1, BN-2, BN-3, BN-4, BN-O-1, BN-O-2, BN-O-3, and BN-O-4 as thermally conductive fillers, the thermal conductivity are 0.68 W/m·K, 0.61 W/m·K, 0.5 W/m·K, 0.52 W/m·K, 0.97 W/m·K, 0.81 W/m·K, 0.76 W/m·K, and 0.77 W/m·K, respectively. The thermal conductivity is increased by 56.69%, 41.48%, 16.27%, 20.93%, 122.23%, 87.15%, 75.48%, and 77.56% with the addition of thermally conductive filler compared with the matrix. Therefore, oxygen-doped rod-shaped boron nitride can be a competitive candidate for high thermal conductivity additives in water-based.

A polyethersulfone film porous wick for loop heat pipes

Loop heat pipe (LHP), which is the star-rated way to solve high heat flux heat transfer, is a promising heat dissipation technology for electronic devices. The optimized design of porous wick in LHP has become the key to increasing the heat transfer capacity and reducing costs. In this study, a polymer material-polyethersulfone (PES) film was chosen as the porous wick. Theoretically, the PES wick has a special structure with dual pore size, which achieves a synergistic enhancement of capillary force and permeability. The experimental investigation compared the heat transfer capacity of LHP with the PES wick, copper mesh wick, and sintered nickel powder wick. The PES wick shows a most significant performance than the other two wicks. The heating surface temperature remains 62 °C in a 55% filling ratio when the LHP is under 300 W heat load. The LHP system and evaporator have respectively the thermal resistance of 0.161 °C/W and 0.056 °C/W. In addition, PES wick shows great potential for application in the LHP field with the advantages of light weight, simple preparation, and low cost. This paper sheds some light on the LHP wick choice to enhance heat transfer.

Optimization study of vehicle thermal management based on vibration heat dissipation

Although vibration is a vital means for ameliorating heat dissipation, it is rarely used in the research and development of vehicle thermal management. This research investigated the problem of the engine outlet water temperature of a vehicle exceeding the temperature limit. The effects of vibration on the fin-tube radiator heat dissipation were examined, and a systematic optimization analysis method for vehicle thermal management based on vibration enhanced heat dissipation technology was proposed. First, experiments on the vibration and heat dissipation characteristics of the radiator were conducted, and the principle of the vibration on the performance of the radiator was obtained. Second, the obtained experimental results were adopted, and an integrated calculation model for the target vehicle was developed to facilitate calculations of the engine outlet water temperature under different vibration conditions. Third, the optimization of the thermal management, based on the calculation model, radial basis function neural network and particle swarm optimization algorithm, was conducted to obtain the minimum value of engine outlet water temperature and the corresponding vibration parameters. Finally, validation of a vehicle’s environmental chamber experiment was implemented. This study provides a solution for the applications of vibration-enhanced heat dissipation technology in vehicle design.