The Experts below are selected from a list of 16467 Experts worldwide ranked by ideXlab platform
Chungen Yin - One of the best experts on this subject based on the ideXlab platform.
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a gas Radiation Property model applicable to general combustion cfd and its demonstration in oxy fuel combustion simulation
Energy Procedia, 2017Co-Authors: Chungen Yin, Shashank Singh, Sergio Sanchez RomeroAbstract:Abstract As a good compromise between computational efficiency and accuracy, the weighted-sum-of-gray-gases model (WSGGM) is often used in computational fluid dynamics (CFD) modeling of combustion processes for evaluating gas radiative properties. However, the WSGGMs still have practical limitations (e.g., difficult to naturally accommodate different combustion environments or accurately address species variations in a flame or properly account for the impacts of participating species other than H 2 O and CO 2 ) fostering different WSGGMs. In this paper, a gas Radiation model, computationally efficient and practically accurate and applicable to general combustion CFD, is presented, programmed and verified. The model is implemented in CFD simulation of a 0.8 MW oxy-fuel furnace, via which the applicability and usefulness of the model in combustion CFD is demonstrated. On the contrary, the usefulness of the WSGGMs in oxy-fuel combustion CFD is found to be compromised, mainly because that the important impacts of the high levels of CO under oxy-fuel combustion cannot be accounted for in the current framework of the WSGGMs.
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prediction of air fuel and oxy fuel combustion through a generic gas Radiation Property model
Applied Energy, 2017Co-Authors: Chungen YinAbstract:Thermal Radiation plays an important role in heat transfer in combustion furnaces. The weighted-sum-of-gray-gases model (WSGGM), representing a good compromise between computational efficiency and accuracy, is commonly used in computational fluid dynamics (CFD) modeling of combustion processes for evaluating gaseous radiative properties. However, the WSGGMs still have some limitations in practical use, e.g., unable to naturally accommodate different combustion environments, difficult to accurately address the variations in species concentrations in a flame, and inconvenient to account for the impacts of participating species other than H2O and CO2. As a result, WSGGMs with different coefficients have been published for specific applications. In this paper, a reliable generic model for gaseous Radiation Property calculation, which is a computationally efficient exponential wide band model (E-EWBM) applicable to combustion CFD and able to naturally solve all the practical limitations of the WSGGMs, is presented, programmed and verified. The model is then implemented to CFD simulation of a 300kW air-fuel and a 0.8MW oxy-fuel combustion furnace, respectively, to demonstrate its computational applicability to general combustion CFD and its capability in producing reliable CFD results for different combustion environments. It is found that the usefulness of the WSGGMs in oxy-fuel combustion CFD is compromised if the important impacts of high levels of CO under oxy-fuel combustion cannot be accounted for. The E-EWBM that appropriately takes the impacts of H2O, CO2, CO and CH4 into account is a good replacement of the oxy-fuel WSGGMs for oxy-fuel combustion CFD.
Feng Hua Kuang - One of the best experts on this subject based on the ideXlab platform.
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crystallization and infrared Radiation properties of iron ion doped cordierite glass ceramics
Journal of Alloys and Compounds, 2011Co-Authors: Shu Ming Wang, Feng Hua Kuang, Qing Zhi YanAbstract:Abstract Heterogeneous ion solution is an important method to improve the wanted Property of polycrystalline materials. In this paper, for the purpose of infrared Radiation Property modification, different contents Fe 2 O 3 were doped in MgO–Al 2 O 3 –SiO 2 system glasses. The effects of Fe 2 O 3 doping on nucleation mechanism, crystallization behaviors and especially infrared Radiation properties of this cordierite-crystalline based glass-ceramics were systematically investigated by means of differential thermal analysis (DTA), X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The results show that, the doping of iron ion can promote the phase separation of this magnesium aluminosilicate glass, and therefore change the crystallization mechanism of this glass from surface crystallization to bulk crystallization. The iron ion incorporates into the crystal structure of cordierite by mean of substituting Mg 2+ in M site. The substitution of Fe 3+ to Mg 2+ can form the vacant site of Mg 2+ cations. For the effects of lattice distortion, impurity and vacancy defects which caused by the incorporation of iron ion, the infrared Radiation performance of cordierite based glass-ceramics can be improved effectively.
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sol gel preparation and infrared Radiation Property of boron substituted cordierite glass ceramics
Journal of Materials Science & Technology, 2010Co-Authors: Shu Ming Wang, Feng Hua KuangAbstract:Boron for aluminum substitution in the cordierite structure has been examined by sol-gel preparation of different samples along the compositional junction Mg 2 Al 4- x B x Si 5 O 18 with x =0, 0.5, 1, 1.5. By increasing the x value from 0 to 1.5 the crystallization behavior changed accordingly. Proper amount B 2 O 3 doping can promote the sintering of amorphous cordierite gel, effectively restrain the precipitation of μ-cordierite and enhance the crystallization of α-cordierite. The substitution of B 3+ for Al 3+ in cordierite crystal structure can effectively improve the near-infrared spectral emissivity of this cordierite based glass-ceramics.
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Testing and Evaluation of Infrared Radiation Property of Cordierite Based Glass-Ceramic Materials
Advanced Materials Research, 2010Co-Authors: Shu Ming Wang, Ying Chun Zhang, Feng Hua Kuang, Qing Zhi YanAbstract:In this article we present the testing, evaluation of infrared Radiation properties of polycrystalline materials especially as cordierite-based glass-ceramics. Researches aim to make a comprehensive and systematic exposition of emissivity definition, test principles and test methods. And on the basis of measurement results of the infrared emissivity of cordierite-based glass-ceramics, the Infrared Radiation Property of this polycrystalline material was discussed. Research has a positive significance on the development of the infrared Radiation heating and drying materials.
Sergio Sanchez Romero - One of the best experts on this subject based on the ideXlab platform.
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a gas Radiation Property model applicable to general combustion cfd and its demonstration in oxy fuel combustion simulation
Energy Procedia, 2017Co-Authors: Chungen Yin, Shashank Singh, Sergio Sanchez RomeroAbstract:Abstract As a good compromise between computational efficiency and accuracy, the weighted-sum-of-gray-gases model (WSGGM) is often used in computational fluid dynamics (CFD) modeling of combustion processes for evaluating gas radiative properties. However, the WSGGMs still have practical limitations (e.g., difficult to naturally accommodate different combustion environments or accurately address species variations in a flame or properly account for the impacts of participating species other than H 2 O and CO 2 ) fostering different WSGGMs. In this paper, a gas Radiation model, computationally efficient and practically accurate and applicable to general combustion CFD, is presented, programmed and verified. The model is implemented in CFD simulation of a 0.8 MW oxy-fuel furnace, via which the applicability and usefulness of the model in combustion CFD is demonstrated. On the contrary, the usefulness of the WSGGMs in oxy-fuel combustion CFD is found to be compromised, mainly because that the important impacts of the high levels of CO under oxy-fuel combustion cannot be accounted for in the current framework of the WSGGMs.
Shu Ming Wang - One of the best experts on this subject based on the ideXlab platform.
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crystallization and infrared Radiation properties of iron ion doped cordierite glass ceramics
Journal of Alloys and Compounds, 2011Co-Authors: Shu Ming Wang, Feng Hua Kuang, Qing Zhi YanAbstract:Abstract Heterogeneous ion solution is an important method to improve the wanted Property of polycrystalline materials. In this paper, for the purpose of infrared Radiation Property modification, different contents Fe 2 O 3 were doped in MgO–Al 2 O 3 –SiO 2 system glasses. The effects of Fe 2 O 3 doping on nucleation mechanism, crystallization behaviors and especially infrared Radiation properties of this cordierite-crystalline based glass-ceramics were systematically investigated by means of differential thermal analysis (DTA), X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The results show that, the doping of iron ion can promote the phase separation of this magnesium aluminosilicate glass, and therefore change the crystallization mechanism of this glass from surface crystallization to bulk crystallization. The iron ion incorporates into the crystal structure of cordierite by mean of substituting Mg 2+ in M site. The substitution of Fe 3+ to Mg 2+ can form the vacant site of Mg 2+ cations. For the effects of lattice distortion, impurity and vacancy defects which caused by the incorporation of iron ion, the infrared Radiation performance of cordierite based glass-ceramics can be improved effectively.
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sol gel preparation and infrared Radiation Property of boron substituted cordierite glass ceramics
Journal of Materials Science & Technology, 2010Co-Authors: Shu Ming Wang, Feng Hua KuangAbstract:Boron for aluminum substitution in the cordierite structure has been examined by sol-gel preparation of different samples along the compositional junction Mg 2 Al 4- x B x Si 5 O 18 with x =0, 0.5, 1, 1.5. By increasing the x value from 0 to 1.5 the crystallization behavior changed accordingly. Proper amount B 2 O 3 doping can promote the sintering of amorphous cordierite gel, effectively restrain the precipitation of μ-cordierite and enhance the crystallization of α-cordierite. The substitution of B 3+ for Al 3+ in cordierite crystal structure can effectively improve the near-infrared spectral emissivity of this cordierite based glass-ceramics.
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Testing and Evaluation of Infrared Radiation Property of Cordierite Based Glass-Ceramic Materials
Advanced Materials Research, 2010Co-Authors: Shu Ming Wang, Ying Chun Zhang, Feng Hua Kuang, Qing Zhi YanAbstract:In this article we present the testing, evaluation of infrared Radiation properties of polycrystalline materials especially as cordierite-based glass-ceramics. Researches aim to make a comprehensive and systematic exposition of emissivity definition, test principles and test methods. And on the basis of measurement results of the infrared emissivity of cordierite-based glass-ceramics, the Infrared Radiation Property of this polycrystalline material was discussed. Research has a positive significance on the development of the infrared Radiation heating and drying materials.
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crystallization behavior and infrared Radiation Property of nickel magnesium cordierite based glass ceramics
Journal of Non-crystalline Solids, 2008Co-Authors: Shu Ming Wang, Kaiming LiangAbstract:Abstract Crystallization behavior of MgO–Al2O3–SiO2 system glasses doped with NiO was investigated by means of differential thermal analysis (DTA), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The infrared Radiation Property of this material was examined via the measurement of the whole-band normal direction emissivity. The results demonstrate that the adding of NiO can suppress the precipitation of μ-cordierite and promote the crystallization of α-cordierite in MgO–Al2O3–SiO2 glasses. As the Ni2+ incorporated into the crystal structure of α-cordierite, the infrared radiance of this material can be improved and the whole-band normal direction emissivity can reach 0.90.
Yirui Zhang - One of the best experts on this subject based on the ideXlab platform.
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high temperature thermal Radiation Property measurements on large periodic micro structured nickel surfaces fabricated using a femtosecond laser source
Applied Surface Science, 2018Co-Authors: Yirui Zhang, Congling ShiAbstract:Abstract Microstructures enable many kinds of surface modifications with unique physical characteristics. The difficulties in fabricating microstructures on large metallic surfaces, however, may limit their wide use. This work measured the thermal Radiation characteristics of large, three-dimensional microstructured metal surfaces where the microstructures were fabricated by a femtosecond laser to investigate the influence of the surface microstructures on the thermal Radiation properties at elevated temperatures. The microstructured nickel surfaces with the microholes having the periods of 100 μm (aligned array) and 71 μm (staggered array) were fabricated by different femtosecond laser pulses (200 and 2000) and fluences (0.138 J/cm2 and 0.276 J/cm2). The microhole diameter was close to 20 μm and the depth was 50–120 μm with large aspect ratios above 2.5. Measurements of the thermal Radiation properties of a polished bare nickel surface and surfaces with microholes showed that the topography greatly affected the surface Radiation properties with increased emissivities (maximum increase of 55%) at temperatures from 700 K to 1200 K. It mainly arises from the multiple reflections inside the microholes and even cavity resonance inside some of the microholes. The work provides a valuable reference for fabricating 3D periodic microstructures on large metallic surfaces and shows how the engineered microstructure surfaces affect the thermal Radiation at elevated temperatures.
