The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform
Yongping Chen - One of the best experts on this subject based on the ideXlab platform.
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melting behaviors of pcm in Porous Metal foam characterized by fractal geometry
International Journal of Heat and Mass Transfer, 2017Co-Authors: Zilong Deng, Chengbin Zhang, Xiangdong Liu, Yongping Huang, Yongping ChenAbstract:Abstract The fractal Brownian motion is introduced to describe the pore distribution of Porous Metal foam. By the fractal description, a model of melting heat transfer for the phase change material (PCM) is developed and applied to investigate the melting behaviors in Porous Metal foam with a particular focus on the role of pore distribution. The dynamic response of temperature and the evolution of melting front are presented. The effects of porosity and fractal dimension on the melting heat transfer are all examined and investigated. In addition, an experiment of melting heat transfer is performed to verify the present model. The results indicate that the Porous Metal foam is of significance for the enhancement of melting heat transfer. When compared with PCM alone, the melting process in Porous Metal foam possesses the larger melting rate, the faster evolution of melting front and the higher liquid fraction. Unlike the PCM alone, the melting front is no longer continuous and many independent solid-liquid interfaces are formed inside pores owing to the interstitial heat transfer. Interestingly, the melting phase change is also affected by the fractal dimension even though the porosity is identical. A Porous Metal foam with smaller fractal dimension is beneficial for the melting heat transfer.
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STUDY ON SOLIDIFICATION OF PHASE CHANGE MATERIAL IN FRACTAL Porous Metal FOAM
Fractals, 2015Co-Authors: Chengbin Zhang, Yongping ChenAbstract:The Sierpinski fractal is introduced to construct the Porous Metal foam. Based on this fractal description, an unsteady heat transfer model accompanied with solidification phase change in fractal Porous Metal foam embedded with phase change material (PCM) is developed and numerically analyzed. The heat transfer processes associated with solidification of PCM embedded in fractal structure is investigated and compared with that in single-pore structure. The results indicate that, for the solidification of phase change material in fractal Porous Metal foam, the PCM is dispersedly distributed in Metal foam and the existence of Porous Metal matrix provides a fast heat flow channel both horizontally and vertically, which induces the enhancement of interstitial heat transfer between the solid matrix and PCM. The solidification performance of the PCM, which is represented by liquid fraction and solidification time, in fractal structure is superior to that in single-pore structure.
Wei Zhou - One of the best experts on this subject based on the ideXlab platform.
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Fabrication of Porous Metal by selective laser melting as catalyst support for hydrogen production microreactor
International Journal of Hydrogen Energy, 2019Co-Authors: Jie Liu, Yu Gao, Yanbin Fan, Wei ZhouAbstract:Abstract To improve the hydrogen production performance of microreactors, the selective laser melting method was proposed to fabricate the Porous Metals as catalyst supports with different pore structures, porosities, and materials. The influence of the Porous structures on the molecule distribution after passing through the Porous Metals was analyzed by molecular dynamics simulation. The developed Porous Metals were then used as catalyst supports in a methanol steam reforming microreactor for hydrogen production. Our results show that the porosity of the Porous Metal had significantly influence on the catalyst infiltration and the reaction process of hydrogen production. A lower degree of catalyst infiltration of the Porous Metal was obtained with lower porosity. A copper layer-coated stainless-steel Porous Metal with a staggered structure and gradient porosity of 80%–60% exhibited much larger methanol conversion and H2 flow rate due to its better heat and mass transfer characteristic. Methanol conversion and H2 flow rates could reach 97% and 0.62 mol/h, respectively. Finally, it was found that the experimental results were in good agreement with the simulation results.
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a Porous Metal organic framework with dynamic pyrimidine groups exhibiting record high methane storage working capacity
Journal of the American Chemical Society, 2014Co-Authors: Hui Min Wen, Wei Zhou, Hailong Wang, Madhusudan Tyagi, Taner Yildirim, Banglin ChenAbstract:We have realized a new Porous Metal–organic framework UTSA-76a with pyrimidine groups on the linker, exhibiting high volumetric methane uptake of ∼260 cm3 (STP) cm–3 at 298 K and 65 bar, and record high working capacity of ∼200 cm3 (STP) cm–3 (between 5 and 65 bar). Such exceptionally high working capacity is attributed to the central “dynamic” pyrimidine groups within UTSA-76a, which are capable of adjusting their orientations to optimize the methane packing at high pressure, as revealed by computational studies and neutron scattering experiments.
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compressive properties of Porous Metal fiber sintered sheet produced by solid state sintering process
Materials & Design, 2012Co-Authors: Wei Zhou, Yong Tang, Rong Song, Lelun JiangAbstract:Abstract A novel Porous Metal fiber sintered sheet (PMFSS) with three-dimensional reticulated structure was fabricated by using solid-state sintering method of copper fibers. Uniaxial compressive test was carried out to investigate the effects of porosity and manufacturing parameters on the compressive properties of PMFSS. During the compressive process, it was found that the PMFSS initially exhibited short-term elastic deformation, and then quickly entered into the compact densification deformation stage. The stress–strain plots showed no obvious yield stage in the whole uniaxial compressive process. Under given stress, the PMFSS with higher porosity exhibited higher strain, hence implying lower effective stiffness. Additionally, our results showed that higher sintering temperature or longer sintering time would soften the PMFSS.
Xiaonan Zhang - One of the best experts on this subject based on the ideXlab platform.
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modeling and optimization of sound absorption coefficient of microperforated compressed Porous Metal panel absorber
Applied Acoustics, 2020Co-Authors: Haiqin Duan, Xinmin Shen, Fei Yang, Xiaonan ZhangAbstract:Abstract The microperforated compressed Porous Metal panel (MCPMP) absorber was proposed to develop novel sound absorber with excellent sound absorption performance, fewer utilized materials, and more lightweight. Through treating the compressed Porous Metal with high compression ratio as microperforated panel, theoretical sound absorption model of the MCPMP absorber was constructed through equivalent circuit approach. Structural parameters of the MCPMP absorber were optimized by cuckoo search algorithm for different target frequency range. The obtained optimal MCPMP absorbers were verified by finite element simulation and validated through standing wave tube measurement. Consistencies among the theoretical data, simulation data, and experimental data proved feasibility and accuracy of theoretical sound absorption model, cuckoo search optimization algorithm, and finite element simulation method. Actual average sound absorption coefficients of the optimal MCPMP absorbers with limited total thickness of 20 mm were 0.4679, 0.7069, and 0.7299 when the target frequency ranges were 100–2000 Hz, 100–4000 Hz, and 100–6000 Hz respectively. By comparison with sound absorption performance of the original Porous Metal and those of the 10-layer gradient compressed Porous Metal, effectiveness and practicality of the optimal MCPMP absorber was proved. The developed MCPMP absorber was favorable to enrich the sound absorption theory and promote its practical application.
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Optimization and validation of sound absorption performance of 10-layer gradient compressed Porous Metal
Metals, 2019Co-Authors: Fei Yang, Xinmin Shen, Xiaonan Zhang, Zhizhong LiAbstract:Sound absorption performance of a Porous Metal can be improved by compression and optimal permutation, which is favorable to promote its application in noise reduction. The 10-layer gradient compressed Porous Metal was proposed to obtain optimal sound absorption performance. A theoretical model of the sound absorption coefficient of the multilayer gradient compressed Porous Metal was constructed according to the Johnson-Champoux-Allard model. Optimal parameters for the best sound absorption performance of the 10-layer gradient compressed Porous Metal were achieved by a cuckoo search algorithm with the varied constraint conditions. Preliminary verification of the optimal sound absorber was conducted by the finite element simulation, and further experimental validation was obtained through the standing wave tube measurement. Consistencies among the theoretical data, the simulation data, and the experimental data proved accuracies of the theoretical sound absorption model, the cuckoo search optimization algorithm, and the finite element simulation method. For the investigated frequency ranges of 100–1000 Hz, 100–2000 Hz, 100–4000 Hz, and 100–6000 Hz, actual average sound absorption coefficients of optimal 10-layer gradient compressed Porous Metal were 0.3325, 0.5412, 0.7461, and 0.7617, respectively, which exhibited the larger sound absorption coefficients relative to those of the original Porous Metals and uniform 10-layer compressed Porous Metal with the same thickness of 20 mm.
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Preparation and Characterization of Gradient Compressed Porous Metal for High-Efficiency and Thin-Thickness Acoustic Absorber.
Materials, 2019Co-Authors: Xiaocui Yang, Xinmin Shen, Xiaonan Zhang, Panfeng Bai, Li Zhizhong, Liang Chen, Qin YinAbstract:Increasing absorption efficiency and decreasing total thickness of the acoustic absorber is favorable to promote its practical application. Four compressed Porous Metals with compression ratios of 0%, 30%, 60%, and 90% were prepared to assemble the four-layer gradient compressed Porous Metals, which aimed to develop the acoustic absorber with high-efficiency and thin thickness. Through deriving structural parameters of thickness, porosity, and static flow resistivity for the compressed Porous Metals, theoretical models of sound absorption coefficients of the gradient compressed Porous Metals were constructed through transfer matrix method according to the Johnson–Champoux–Allard model. Sound absorption coefficients of four-layer gradient compressed Porous Metals with the different permutations were theoretically analyzed and experimentally measured, and the optimal average sound absorption coefficient of 60.33% in 100–6000 Hz was obtained with the total thickness of 11 mm. Sound absorption coefficients of the optimal gradient compressed Porous Metal were further compared with those of the simple superposed compressed Porous Metal, which proved that the former could obtain higher absorption efficiency with thinner thickness and fewer materials. These phenomena were explored by morphology characterizations. The developed high-efficiency and thin-thickness acoustic absorber of gradient compressed Porous Metal can be applied in acoustic environmental detection and industrial noise reduction.
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Sound absorption performance of the acoustic absorber fabricated by compression and microperforation of the Porous Metal
Materials & Design, 2019Co-Authors: Xiaocui Yang, Guoliang Jiang, Xinmin Shen, Xiaonan Zhang, Zhizhong Li, Fei YangAbstract:Abstract Novel acoustic absorbers were fabricated by the compression and microperforation of the Porous Metal, which aimed to develop practical acoustic absorbers for the noise reduction. Sound absorbing coefficients of the five investigated acoustic absorbers were measured by the AWA6128A detector according to the standing wave method, and their trends were consistent with normal sound absorption principle of the Porous Metal absorber and that of the microperforated panel absorber. The results proved that with same length of the cavity, sound absorption performance could be obviously improved by the compression and microperforation. When length of the cavity was 20 mm, average sound absorbing coefficient of the compressed and microperforated Porous Metal panel absorber in frequency range 100–6000 Hz reached 59.69%, which was superior to that 25.70% of original Porous Metal absorber and that 31.49% of the microperforated spring steel panel absorber. In the constructed semi-empirical model, a fourth-order polynomial function was treated as the coupling function to express the superposition absorption effect, and its veracity and reliability was validated by two replication experiments. Micromorphology of the compressed and microperforated Porous Metal panel provided the intuitive explanations to the improvement of its sound absorption performance.
Fei Yang - One of the best experts on this subject based on the ideXlab platform.
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modeling and optimization of sound absorption coefficient of microperforated compressed Porous Metal panel absorber
Applied Acoustics, 2020Co-Authors: Haiqin Duan, Xinmin Shen, Fei Yang, Xiaonan ZhangAbstract:Abstract The microperforated compressed Porous Metal panel (MCPMP) absorber was proposed to develop novel sound absorber with excellent sound absorption performance, fewer utilized materials, and more lightweight. Through treating the compressed Porous Metal with high compression ratio as microperforated panel, theoretical sound absorption model of the MCPMP absorber was constructed through equivalent circuit approach. Structural parameters of the MCPMP absorber were optimized by cuckoo search algorithm for different target frequency range. The obtained optimal MCPMP absorbers were verified by finite element simulation and validated through standing wave tube measurement. Consistencies among the theoretical data, simulation data, and experimental data proved feasibility and accuracy of theoretical sound absorption model, cuckoo search optimization algorithm, and finite element simulation method. Actual average sound absorption coefficients of the optimal MCPMP absorbers with limited total thickness of 20 mm were 0.4679, 0.7069, and 0.7299 when the target frequency ranges were 100–2000 Hz, 100–4000 Hz, and 100–6000 Hz respectively. By comparison with sound absorption performance of the original Porous Metal and those of the 10-layer gradient compressed Porous Metal, effectiveness and practicality of the optimal MCPMP absorber was proved. The developed MCPMP absorber was favorable to enrich the sound absorption theory and promote its practical application.
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Optimization and validation of sound absorption performance of 10-layer gradient compressed Porous Metal
Metals, 2019Co-Authors: Fei Yang, Xinmin Shen, Xiaonan Zhang, Zhizhong LiAbstract:Sound absorption performance of a Porous Metal can be improved by compression and optimal permutation, which is favorable to promote its application in noise reduction. The 10-layer gradient compressed Porous Metal was proposed to obtain optimal sound absorption performance. A theoretical model of the sound absorption coefficient of the multilayer gradient compressed Porous Metal was constructed according to the Johnson-Champoux-Allard model. Optimal parameters for the best sound absorption performance of the 10-layer gradient compressed Porous Metal were achieved by a cuckoo search algorithm with the varied constraint conditions. Preliminary verification of the optimal sound absorber was conducted by the finite element simulation, and further experimental validation was obtained through the standing wave tube measurement. Consistencies among the theoretical data, the simulation data, and the experimental data proved accuracies of the theoretical sound absorption model, the cuckoo search optimization algorithm, and the finite element simulation method. For the investigated frequency ranges of 100–1000 Hz, 100–2000 Hz, 100–4000 Hz, and 100–6000 Hz, actual average sound absorption coefficients of optimal 10-layer gradient compressed Porous Metal were 0.3325, 0.5412, 0.7461, and 0.7617, respectively, which exhibited the larger sound absorption coefficients relative to those of the original Porous Metals and uniform 10-layer compressed Porous Metal with the same thickness of 20 mm.
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Sound absorption performance of the acoustic absorber fabricated by compression and microperforation of the Porous Metal
Materials & Design, 2019Co-Authors: Xiaocui Yang, Guoliang Jiang, Xinmin Shen, Xiaonan Zhang, Zhizhong Li, Fei YangAbstract:Abstract Novel acoustic absorbers were fabricated by the compression and microperforation of the Porous Metal, which aimed to develop practical acoustic absorbers for the noise reduction. Sound absorbing coefficients of the five investigated acoustic absorbers were measured by the AWA6128A detector according to the standing wave method, and their trends were consistent with normal sound absorption principle of the Porous Metal absorber and that of the microperforated panel absorber. The results proved that with same length of the cavity, sound absorption performance could be obviously improved by the compression and microperforation. When length of the cavity was 20 mm, average sound absorbing coefficient of the compressed and microperforated Porous Metal panel absorber in frequency range 100–6000 Hz reached 59.69%, which was superior to that 25.70% of original Porous Metal absorber and that 31.49% of the microperforated spring steel panel absorber. In the constructed semi-empirical model, a fourth-order polynomial function was treated as the coupling function to express the superposition absorption effect, and its veracity and reliability was validated by two replication experiments. Micromorphology of the compressed and microperforated Porous Metal panel provided the intuitive explanations to the improvement of its sound absorption performance.
Guojian Wang - One of the best experts on this subject based on the ideXlab platform.
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a multifunctional 3d ferroelectric and nlo active Porous Metal organic framework
Journal of the American Chemical Society, 2009Co-Authors: Zhengang Guo, Rong Cao, Xin Wang, Wenbing Yuan, Guojian WangAbstract:The tetracarboxylate organic linker and Zn(II) ions assemble into chiral building blocks for a Porous Metal−organic framework with ferroelectric and second-order nonlinear optical properties.
