检索结果-南通市图书馆

Experimental Research on Thermal Performance of Ultra-Thin Flattened Heat Pipes

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2022年第6期31卷 2346-2362页

作者： TANG Yongle CAO Jianguang wang shuangfeng Key Lab of Heat Transfer Enhancement and Energy Conservation of Ministry of Education School of Chemistry and Chemical EngineeringSouth China University of TechnologyGuangzhou 510640China Shanghai Institute of Satellite Engineering Shanghai 200240China

Ultra-thin flattened heat pipe(UTHP) is an effective solution to solve the problem of high-power density heat dissipation in narrow space. The key factors that determine its thermal performance include: the shapes and sizes of the UTHP, the wick structure, the type of working fluid and its filling ratio. The change in the filling ratio means not only a change in the amount of the working fluid, but also a change in the space distribution of the gas and liquid phases inside the heat pipe. Therefore, it is important to explore the effect of liquid filling ratio on the thermal performance of UTHP. It can provide effective guidance for the production of UTHP. In this work, experiments were conducted on four groups of UTHPs with different mesh wicks under a series of liquid filling ratios. The results demonstrate that the volume of the filling working fluid should account for 22%-37% of the total internal volume of the UTHP to avoid deterioration of heat transfer during the operation of the UTHP. In addition, a prediction model of the evaporator temperature has been established to provide guidance for the application of UTHPs.

关键词： ultra-thin flattened heat pipe liquid filling ratio gas-liquid phase space distribution thermal performance prediction model

Numerical study on turbulent mixed convection in a vertical plane channel using hybrid RANS/LES and LES models

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2020年第1期28卷 1-8页

作者： Puxian Ding shuangfeng wang Kai Chen Key Laboratory of Enhanced Heat Transfer and Energy Conservation of the Ministry of Education School of Chemistry and Chemical EngineeringSouth China University of TechnologyGuangzhou 510640China

Two Delayed-Detached Eddy Simulation(DDES) models, and a Large-Eddy Simulation(LES) model are used to investigate the turbulent flows and mixed convection between a hot plate and a cold plate via the software FLUENT. The two DDES models include Production-limited DDES(PL-DDES) and Improved DDES(IDDES) *** Wall-Adapting Local Eddy-Viscosity(WALE) model is the used LES model. The numerical computations are performed at Reynolds number Reb= 4494 and different Richardson numbers Ri = 0.025, 0.048, 0.1. The comparing data is from the Direct Numerical Simulation(DNS) at Reb= 4494 and Ri = 0.048. The comparison reveals that the two DDES models have better performance in predicting time-averaged parameters than the WALE model in the aiding flow. The best predicted time-averaged results are obtained by the PL-DDES model in the opposing flow. Furthermore, the results of different Ri obtained by the PL-DDES model agree well with the DNS data.

关键词： Turbulent mixed convection Hybrid RANS/LES model PL-DDES model WALE model Vertical plane channel

Numerical study on effects of the cofferdam area in liquefied natural gas storage tank on the leakage and diffusion characteristics of natural gas

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2021年第1期34卷 228-241页

作者： Zirong Lin shuangfeng wang Shuxun Fu Jiepeng Huo Foshan Public Utilities Holding Co.Ltd. GuangdongFoshan 528000China South China University of Technology GuangdongGuangzhou 510640China Foshan gas group Co.Ltd. GuangdongFoshan 528000China Guangzhou Institute of Energy Conversion Chinese Academy of SciencesGuangdongGuangzhou 510640China

The leakage and diffusion characteristics of natural gas were investigated in the condition of the leakage of liquefied natural gas(LNG) in the storage *** was adopted to simulate the process in a series of three-dimension unsteady state *** effects of different heights of the cofferdam(1.0 m, 2.0 m and 3.0 m),wind directions,ambient temperature,leakage location,leakage volume on the diffusion process of natural gas were *** diffusion characteristics of the natural gas clouds over cofferdam were *** windless condition,when the gas clouds met,the gas clouds rose due to the collision,which made them easier to cross the cofferdam and spread *** higher the ambient temperature was,the higher the gas concentration around the cofferdam was,and the smaller the gas concentration difference *** the leakage occurred,the higher coffe rdam was more beneficial to delay the outward diffusion of gas ***,when the leaka ge stopped,the higher cofferdam went against the dissipation of gas *** windy condition,the time to form stable leakage flow field was faster than that of windless,and the lower cofferdam further reduced this ***,considering the effect of barrier and dissipation,it was suggested that the rational height of cofferdam should be designed in the range of 1.0 m to 2.0 *** case of emergency,the leakage of gas should be deduced reasonably by combining the measurement of gas concentration with the rolling of gas *** windless,the leakage area should be entered between the overflows of gas clouds.

关键词： Natural gas Leakage and diffusion Cofferdam Numerical simulation

Effect of Turbulence on Flame Propagation in Comstarch Dust-Air Mixtures

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2006年第2期15卷 186-192页

作者： shuangfeng wang Yikang PU Fu JIA Artur GUTKOWSKI National Microgravity Laboratory Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China Department of Heat Technology and Refrigeration Technical University of Lodz Stefanowskiego 1/15 90-924 Lodz Poland

Following the quantitative determination of dust cloud parameters, this study investigated the flame propagation through cornstarch dust clouds in a vertical duct of 780 mm height and 160×160 mm square cross section, and gave particular attention to the effect of turbulence on flame characteristics. The turbulence induced by dust dispersion process was measured using a particle image velocimetry （PIV） system. Upward propagating dust flames were visualized with direct fight and shadow photography. The results show that a critical value of the turbulence intensity can be specified below which laminar flame propagation would be established. This transition condition is about 10 cm/s. The measured propagation speed of laminar flames appears to be in the range of 0.45-0.56 m/s, consistent with the measurements reported in the literature. For the present experimental conditions, the flame speed is little sensitive to the variations in dust concentration. Some information on the flame structure was revealed from the shadow records, showing the typical heterogeneous feature of dust combustion process.

关键词： dust flame flame propagation dust dispersion process turbulence cornstarch

Numerical Simulation of Heat Transfer Performance for Ultra-Thin Flat Heat Pipe

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2023年第2期32卷 643-649页

作者： YAN Wentao YANG Xin LIU Tengqing wang shuangfeng School of Electric Power South China University of TechnologyGuangzhou 510640China Key Laboratory of Enhanced Heat Transfer and Energy Conservation of the Ministry of Education School of Chemistry and Chemical EngineeringSouth China University of TechnologyGuangzhou 510640China

The heat transfer performance of ultra-thin flat heat pipes with#180 copper mesh wick was studied by numerical simulation for different heating *** length,width and height of the ultra-thin flat heat pipe are 80 mm,8.5 mm and 1 mm,*** temperature distribution and flow characteristics of ultra-thin flat heat pipes were simulated by coupling porous media model and user-defined function(UDF)in *** validate the accuracy of the numerical model,the simulation results of the ultra-thin flat heat pipe are compared with the experimental data in predicting the evaporation section *** numerical model has good accuracy for the one-dimensional heat transfer method of ultra-thin flat heat *** velocity,pressure drop of the wick and total temperature difference have the same variation *** the increase of heating power,the temperature difference of ultra-thin flat heat pipes increases,and the pressure drop and the liquid velocity in the wick also increase.

关键词： ultra-thin flat heat pipes evaporation section temperature temperature difference copper mesh simulation

Experimental study on microcapsule fluid oscillating heat pipe

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2009年第6期52卷 1601-1606页

作者： LIN ZiRong wang shuangfeng ZHANG WeiBao Key Laboratory of Enhanced Heat Transfer and Energy Conservation of the Ministry of Education South China University of Tech-nologyGuangzhou 510640China

In this experiment,a four-turn oscillating heat pipe(OHP)is made of copper tube with an inner diameter of 1.3mm,and an outer diameter of 2.5mm.A series of experiments are performed to investigate the startup characteristics of OHP,and the effects of different working fluids(FS-39E microcapsule fluid,pure water,ethanol),different liquid filling rates(40%-80%)on the heat transport capability of OHP in vertical bottom heat *** results show that the startup of OHP is relative with liquid filling rate,thermal driving force and working fluid;and experiences different flow patterns with the increase of heat *** best concentration of FS-39E microcapsule fluid is 1wt%.While FS-39E microcapsule fluid is used as the working fluid,compared with pure water and ethanol,the OHP has a broader working scope;when the liquid filling rate is relatively high,the OHP shows a better performance on the startup and heat transport capability.

关键词： oscillating heat pipes microcapsule fluid liquid filling rate(FR) heat transport capability

3D shape-stable temperature-regulated macro-encapsulated phase change material:KAl(SO_(4))_(2)·12H_(2)O-C_(2)H_(2)O_(4)·2H_(2)O-CO(NH_(2))_(2) eutectic/polyurethane foam as core and carbon modified silicone resin as shell

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2022年第5期100卷 27-35页

作者： Weicheng Chen Xianghui Liang Wanhui Han shuangfeng wang Xuenong Gao Zhengguo Zhang Yutang Fang Key Laboratory of Enhanced Heat Transfer and Energy Conservation of the Ministry of Education South China University of TechnologyGuangzhou 510640China

Micro-encapsulated phase change materials(PCMs)have been confirmed a high-efficiency way to store latent heat,but their poor mechanical properties,expensive and complicated synthesis block their industrial ***,borrowing from this structure and magnifying it,we prepared a novel 3D shape-stable temperature-regulated macro-encapsulated *** KAl(SO_(4))_(2)·12H_(2)O-C_(2)H_(2)O_(4)·2H_(2)O-CO(NH_(2))_(2)(APSD-OAD-Urea)was configured as PCM to composite with light-weight porous polyurethane foam(PUF)framework,and the enthalpy reduction of PCM@PUF(core)was only 1.70%.Subsequent,carbon modified silicone resin(CMS,shell)was introduced to macro-encapsulate PCM@*** results showed that with the optimized mass ratio of 75%APSD-25%OAD and extra addition of 10% Urea,the obtained PCM had a relatively high enthalpy(194.6 J/g),appropriate phase transition temperature(42.17℃)and suppressed supercooling(0.504℃).CMS thin-layer with 2.0 mm thickness increased resistance to deformation,impressions,scratches,and possessed a brilliant sealing effect on PCM@PUF to achieve leak-free and operation steady of ***@PUF@CMS with low thermal conductivity from inside out displayed an outstanding thermal insulation ***,the fluctuation of the thermodynamic property after 150 thermal cycles is relatively *** these above enable the application of PCM@PUF@CMS in the thermal energy storage system and provide a novel strategy for the preparation of macro-encapsulated PCMs.

关键词： Eutectic Temperature-regulated Foam porous framework Macro-encapsulated PCM Thermal energy storage

A Xanthomonas oryzae pv. oryzae effector, Xop R, associates with receptor-like cytoplasmic kinases and suppresses PAMP-triggered stomatal closure

在线全文

学校读者我要写书评

暂无评论

Science China(Life Sciences) 2016年第9期59卷 897-905页

作者： shuangfeng wang Jianhang Sun Fenggui Fan Zhaoyun Tan Yanmin Zou Dongping Lu State Key Laboratory of Plant Genomics Center for Agricultural Research Resources Institute of Genetics and Developmental Biology Chinese Academy of Sciences Shijiazhuang Hebei 050021 China University of Chinese Academy of Sciences Beijing 100049 China

Receptor-like kinases(RLKs) play important roles in plant immunity signaling; thus, many are hijacked by pathogen effectors to promote successful pathogenesis. Xanthomonas oryzae pv. oryzae(Xoo) is the causal agent of rice leaf blight disease. The strain PXO99 A has 18 non-TAL(transcription activation-like) effectors; however, their mechanisms of action and host target proteins remain largely unknown. Although the effector XopR from the Xoo strain MAFF311018 was shown to suppress PAMP-triggered immune responses in Arabidopsis, its target has not yet been identified. Here, we show that PXO99 A XopR interacts with BIK1 at the plasma membrane. BIK1 is a receptor-like cytoplasmic kinase(RLCK) belonging to the RLK family of proteins and mediates PAMP-triggered stomatal immunity. In turn, BIK1 phosphorylates XopR. Furthermore, XopR suppresses PAMP-triggered stomatal closure in transgenic Arabidopsis expressing XopR. In addition, XopR is able to associate with RLCKs other than BIK1. These results suggest that XopR likely suppresses plant immunity by targeting BIK1 and other RLCKs.

关键词： Xanthomonas effector XopR BIK1 immunity

Observation of the Turbulent Burst near ASheared Air-Water Interface

在线全文

学校读者我要写书评

暂无评论

Communications in Nonlinear Science and Numerical Simulation 1999年第2期4卷 94-99页

作者： shuangfeng wang Fu JIA Zhennan NIU Zhangzhi WU(Institute of Mechanics, Chinese Academy of Sciences, Beijing 100080, China)(State Key Laboratory for Turbulence Research, Peking University, Beijing 100871,China) Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China

The turbulent burst under a sheared air-water interface was experimentally investigated using hydrogen bubble visualization technique. The surface shear wasimposed by an airflow over the water flow which was kept free from surface waves. Resultsshow that the wind shear has the main influence on the bursting events. At relativelyhigh shear rates, the flow near the interface is dominated primarily by intermittent bursting events. The general features of bursting processes are described in some detail. Theobserved bursting events show qualitative similarities with those occurring in near-wallturbulence. However, a few distinctive phenomena were also observed, including the existence of vertical vortices and thickening process of the boundary layer, which appear tobe associated with the Characteristics of air-water interface.

关键词： air-water interface turbulent burst flow-visualization