A total of 540 nonlinear steady-state finite element analyses were performed to study the influence of temperature and dimensionless geometrical parameters(β,γ,θ,andτ)on the ultimate strength,failure modes,and ini...A total of 540 nonlinear steady-state finite element analyses were performed to study the influence of temperature and dimensionless geometrical parameters(β,γ,θ,andτ)on the ultimate strength,failure modes,and initial stiffness of two-planar tubular KT-joints.The joints were analyzed under two types of axial loading and five different temperatures(20℃,200℃,400℃,550℃,and 700℃).So far,there has not been any equation available for calculating the ultimate strength of two-planar tubular KT-joints at elevated temperatures.Hence,after parametric study,a set of design formulas were developed through nonlinear regression analyses,to calculate the ultimate strength of two-planar tubular KT-joints subjected to axial loading at elevated temperatures.展开更多
数学模型是研究相对渗透率与饱和度关系曲线的重要方法。采用自行开发设计的人工平面多孔介质模型,测定了相对渗透率与饱和度的关系曲线。多孔介质选择粒径为0.5～1mm、1～2mm的标准砂,纯净的水为湿润相,用3号苏丹红染色的93#汽油为非...数学模型是研究相对渗透率与饱和度关系曲线的重要方法。采用自行开发设计的人工平面多孔介质模型,测定了相对渗透率与饱和度的关系曲线。多孔介质选择粒径为0.5～1mm、1～2mm的标准砂,纯净的水为湿润相,用3号苏丹红染色的93#汽油为非湿润相,组成多孔介质油水两相流动系统。采用Van Genuchten and Mualeum(VGM)和Brooks-Corey-Burdine(BCB)两种数学模型计算相对渗透率与饱和度的关系曲线,通过比较两种数学模型计算结果之间和模型计算结果与实测结果的差异以及模型的应用、多相渗流系统自身特征,得出VGM、BCB两种数学模型计算结果符合实际情况,VGM模型应用过程更为简便,但VGM模型具有一定适用条件;在砂性多孔介质中,BCB模型计算相对渗透率与饱和度关系曲线更准确。展开更多
文摘A total of 540 nonlinear steady-state finite element analyses were performed to study the influence of temperature and dimensionless geometrical parameters(β,γ,θ,andτ)on the ultimate strength,failure modes,and initial stiffness of two-planar tubular KT-joints.The joints were analyzed under two types of axial loading and five different temperatures(20℃,200℃,400℃,550℃,and 700℃).So far,there has not been any equation available for calculating the ultimate strength of two-planar tubular KT-joints at elevated temperatures.Hence,after parametric study,a set of design formulas were developed through nonlinear regression analyses,to calculate the ultimate strength of two-planar tubular KT-joints subjected to axial loading at elevated temperatures.
文摘数学模型是研究相对渗透率与饱和度关系曲线的重要方法。采用自行开发设计的人工平面多孔介质模型,测定了相对渗透率与饱和度的关系曲线。多孔介质选择粒径为0.5～1mm、1～2mm的标准砂,纯净的水为湿润相,用3号苏丹红染色的93#汽油为非湿润相,组成多孔介质油水两相流动系统。采用Van Genuchten and Mualeum(VGM)和Brooks-Corey-Burdine(BCB)两种数学模型计算相对渗透率与饱和度的关系曲线,通过比较两种数学模型计算结果之间和模型计算结果与实测结果的差异以及模型的应用、多相渗流系统自身特征,得出VGM、BCB两种数学模型计算结果符合实际情况,VGM模型应用过程更为简便,但VGM模型具有一定适用条件;在砂性多孔介质中,BCB模型计算相对渗透率与饱和度关系曲线更准确。
