Electrodes,catalysts,membranes,if present,are three main components in constructing an MFC for harvesting desired maximum power density and achieving higher coulombic efficiency (CE).Great improvements have been made,...Electrodes,catalysts,membranes,if present,are three main components in constructing an MFC for harvesting desired maximum power density and achieving higher coulombic efficiency (CE).Great improvements have been made,based on previous researches,in developing and diversifying materials,aside from architectures.Electrodes most familiar to us are widely used carbon materials.For anodes,carbon matrix composites(e.g.,a combination of polyaniline(PANI)with TiO2 using carbon as substrate)have gained special attention,though carbon material itself can exhibit excellent performance by diversifying molecular structures such as carbon nanotubes(CNTs).In the meanwhile,the evolution of MFC architectures,heading to the direction of improving power generation,contributes to the combination of membranes and cathodes from separate modes to diverse assemblies,on which all sorts of catalysts,such as from commonly used Pt to iron phthalocyanine (Pc),metal tetramethoxyphenylporphyrin(TMPP),MnOx,or pyrolyzed iron(Ⅱ)phthalocyanine (pyr-FePc),can be immobilized through synthesis of these catalysts with polymer such as Nafion 117 (Dupont Co.,USA)or tetrafluoroethylen(eTeflon)containing functional groups or Polypyrrol(ePPy).In addition,catholytes with aqueous cathode immersed or flowing through the surface of air-cathode are favorably proposed containing transition metal redox couples or iron chelates.展开更多
针对笛卡尔坐标系下的VOF(volume of fluid)方法无法精确模拟复杂边界的自由表面流动问题,以连续方程和雷诺平均方程为基本控制方程,采用k-ε湍流模型来封闭方程组,修正了基于交错网格的贴体坐标系下的SIMPLE算法来迭代求解压力-速度场...针对笛卡尔坐标系下的VOF(volume of fluid)方法无法精确模拟复杂边界的自由表面流动问题,以连续方程和雷诺平均方程为基本控制方程,采用k-ε湍流模型来封闭方程组,修正了基于交错网格的贴体坐标系下的SIMPLE算法来迭代求解压力-速度场,修正了贴体坐标系下的界面跟踪方法,建立了基于BFC-VOF方法求解波浪对弧形胸墙结构作用的数值计算模型.对弧形胸墙结构附近的波面、流场及其所受波浪力等进行了数值模拟.研究结果表明:贴体网格模型能够精确模拟复杂边界的自由表面流动问题,模型计算的弧形胸墙迎浪面所受到的波浪力随着圆弧半径的增大而减小.展开更多
In this paper, cold simulation experiments and numerical calculations are conducted to predict 3 D flow field aerodynamics for an oil furnace after being retrofitted due to its fuel variation. K ε model and SIMPLE ...In this paper, cold simulation experiments and numerical calculations are conducted to predict 3 D flow field aerodynamics for an oil furnace after being retrofitted due to its fuel variation. K ε model and SIMPLE program under body fit coordination (BFC) system, in which TTM non orthogonal method is used to control the irregular geometric boundary, are adopted to solve the control equations. Model tests are conducted to check the calculation results, showing that they are in agreement with each other. Three different alternatives with different side window locations are also calculated to optimize the designs. The field retrofitting results show that the combination of cold tests with numerical calculations has prosperous application in retrofitting or renewing medium and small boilers.展开更多
文摘Electrodes,catalysts,membranes,if present,are three main components in constructing an MFC for harvesting desired maximum power density and achieving higher coulombic efficiency (CE).Great improvements have been made,based on previous researches,in developing and diversifying materials,aside from architectures.Electrodes most familiar to us are widely used carbon materials.For anodes,carbon matrix composites(e.g.,a combination of polyaniline(PANI)with TiO2 using carbon as substrate)have gained special attention,though carbon material itself can exhibit excellent performance by diversifying molecular structures such as carbon nanotubes(CNTs).In the meanwhile,the evolution of MFC architectures,heading to the direction of improving power generation,contributes to the combination of membranes and cathodes from separate modes to diverse assemblies,on which all sorts of catalysts,such as from commonly used Pt to iron phthalocyanine (Pc),metal tetramethoxyphenylporphyrin(TMPP),MnOx,or pyrolyzed iron(Ⅱ)phthalocyanine (pyr-FePc),can be immobilized through synthesis of these catalysts with polymer such as Nafion 117 (Dupont Co.,USA)or tetrafluoroethylen(eTeflon)containing functional groups or Polypyrrol(ePPy).In addition,catholytes with aqueous cathode immersed or flowing through the surface of air-cathode are favorably proposed containing transition metal redox couples or iron chelates.
文摘针对笛卡尔坐标系下的VOF(volume of fluid)方法无法精确模拟复杂边界的自由表面流动问题,以连续方程和雷诺平均方程为基本控制方程,采用k-ε湍流模型来封闭方程组,修正了基于交错网格的贴体坐标系下的SIMPLE算法来迭代求解压力-速度场,修正了贴体坐标系下的界面跟踪方法,建立了基于BFC-VOF方法求解波浪对弧形胸墙结构作用的数值计算模型.对弧形胸墙结构附近的波面、流场及其所受波浪力等进行了数值模拟.研究结果表明:贴体网格模型能够精确模拟复杂边界的自由表面流动问题,模型计算的弧形胸墙迎浪面所受到的波浪力随着圆弧半径的增大而减小.
文摘In this paper, cold simulation experiments and numerical calculations are conducted to predict 3 D flow field aerodynamics for an oil furnace after being retrofitted due to its fuel variation. K ε model and SIMPLE program under body fit coordination (BFC) system, in which TTM non orthogonal method is used to control the irregular geometric boundary, are adopted to solve the control equations. Model tests are conducted to check the calculation results, showing that they are in agreement with each other. Three different alternatives with different side window locations are also calculated to optimize the designs. The field retrofitting results show that the combination of cold tests with numerical calculations has prosperous application in retrofitting or renewing medium and small boilers.
