为了解决城市地下交通联系隧道(urban traffic link tunnel,UTLT)火灾烟气安全的问题,采用量纲分析方法推导出了UTLT火灾烟气回流长度的量纲一方程式;根据调查的UTLT的常见尺寸,设置了9种不同尺寸的UTLT,运用数值模拟软件FDS 5.5对这些...为了解决城市地下交通联系隧道(urban traffic link tunnel,UTLT)火灾烟气安全的问题,采用量纲分析方法推导出了UTLT火灾烟气回流长度的量纲一方程式;根据调查的UTLT的常见尺寸,设置了9种不同尺寸的UTLT,运用数值模拟软件FDS 5.5对这些隧道进行模拟计算,得到了不同工况下的火灾烟气回流长度,进而得到了UTLT火灾烟气回流长度的预测模型.通过与实验值的比较表明,该方程式和实验值吻合较好.在进一步分析的基础上,得到了UTLT的限制隧道预测模型,可为此类隧道的消防设计提供一定的技术指导.展开更多
The steady two-dimensional magnetohydrodynamic stagnation flow towards a nonlinear stretching surface is studied. The no-slip condition on the solid boundary is replaced with a partial slip condition. A scaling group ...The steady two-dimensional magnetohydrodynamic stagnation flow towards a nonlinear stretching surface is studied. The no-slip condition on the solid boundary is replaced with a partial slip condition. A scaling group transformation is used to get the invariants. Using the invariants, a third-order ordinary differential equation corresponding to the momentum is obtained. An analytical solution is obtained in a series form using a homotopy analysis method. Reliability and efficiency of series solutions are shown by the good agreement with numerical results presented in the literature. The effects of the slip parameter, the magnetic field parameter, the velocity ratio parameter, the suction velocity parameter, and the power law exponent on the flow are investigated. The results show that the velocity and shear stress profiles are greatly influenced by these parameters.展开更多
文摘为了解决城市地下交通联系隧道(urban traffic link tunnel,UTLT)火灾烟气安全的问题,采用量纲分析方法推导出了UTLT火灾烟气回流长度的量纲一方程式;根据调查的UTLT的常见尺寸,设置了9种不同尺寸的UTLT,运用数值模拟软件FDS 5.5对这些隧道进行模拟计算,得到了不同工况下的火灾烟气回流长度,进而得到了UTLT火灾烟气回流长度的预测模型.通过与实验值的比较表明,该方程式和实验值吻合较好.在进一步分析的基础上,得到了UTLT的限制隧道预测模型,可为此类隧道的消防设计提供一定的技术指导.
基金Project supported by the National Natural Science Foundation of China (No. 50936003)the Open Project of State Key Laboratory for Advanced Metals and Materials and the Research Foundation of Engineering Research Institute of University of Science and Technology Beijing (No. 2009Z-02)
文摘The steady two-dimensional magnetohydrodynamic stagnation flow towards a nonlinear stretching surface is studied. The no-slip condition on the solid boundary is replaced with a partial slip condition. A scaling group transformation is used to get the invariants. Using the invariants, a third-order ordinary differential equation corresponding to the momentum is obtained. An analytical solution is obtained in a series form using a homotopy analysis method. Reliability and efficiency of series solutions are shown by the good agreement with numerical results presented in the literature. The effects of the slip parameter, the magnetic field parameter, the velocity ratio parameter, the suction velocity parameter, and the power law exponent on the flow are investigated. The results show that the velocity and shear stress profiles are greatly influenced by these parameters.
