The complex 3D flow in a steam turbine exhaust hood model with different inlet swirl and inlet total pressure radial distributions has been simulated by employing CFX-5 and analyzed in this paper. It＇s found that the...The complex 3D flow in a steam turbine exhaust hood model with different inlet swirl and inlet total pressure radial distributions has been simulated by employing CFX-5 and analyzed in this paper. It＇s found that the inlet tangential flow angle at hub has a negative effect on the exhaust hood performance, while a negative gradient of inlet total pressure radial distribution has a positive impact on the hood performances. It＇s also numerically con- firmed that a proper distribution of total pressure at hood inlet can successfully eliminate the negative effects caused by the inappropriate inlet swirl distribution and improve the hood aerodynamic performance.展开更多
The Random Vortex Method extended to an axisymmetrical flow is used in the study of the flow field inside circular geometries characterized by an axis of symmetry. The method uses a formulation in vorticity variables ...The Random Vortex Method extended to an axisymmetrical flow is used in the study of the flow field inside circular geometries characterized by an axis of symmetry. The method uses a formulation in vorticity variables expressed in cylindrical coordinates with e assumption of all axisymmetrical flow.The algorithm uses a semi-Lagrangian approach for the simulation of the vortex dynamics. In this paper, the algorithm of the computational method, along with a description of the method of vorticity generation on solid walls, are presented in detail.展开更多
The Random Vortex Method extended to an azisymmetrical flow is used in the study of the flow field inside pipes incorporating an orifice plate with different contraction ratios and different inlet velocity profiles. T...The Random Vortex Method extended to an azisymmetrical flow is used in the study of the flow field inside pipes incorporating an orifice plate with different contraction ratios and different inlet velocity profiles. Three test-cases, each having experimental measurements available in the literature, are studied. In particular, instantaneous and average velocity fields along with the turbulent statistics for high Reynolds number flows are computed and compared to the corresponding experimental results.These comparisons show the ability and the citations of the method. The results of the numerical simulations are used in the physical analysis of the flow fields and thus allow for a better understanding of the dynamics of the flow in pipes incorporating an orifice plate.展开更多
基金the National Natural Science Foundation of China (grant No.50336050)
文摘The complex 3D flow in a steam turbine exhaust hood model with different inlet swirl and inlet total pressure radial distributions has been simulated by employing CFX-5 and analyzed in this paper. It＇s found that the inlet tangential flow angle at hub has a negative effect on the exhaust hood performance, while a negative gradient of inlet total pressure radial distribution has a positive impact on the hood performances. It＇s also numerically con- firmed that a proper distribution of total pressure at hood inlet can successfully eliminate the negative effects caused by the inappropriate inlet swirl distribution and improve the hood aerodynamic performance.
文摘The Random Vortex Method extended to an axisymmetrical flow is used in the study of the flow field inside circular geometries characterized by an axis of symmetry. The method uses a formulation in vorticity variables expressed in cylindrical coordinates with e assumption of all axisymmetrical flow.The algorithm uses a semi-Lagrangian approach for the simulation of the vortex dynamics. In this paper, the algorithm of the computational method, along with a description of the method of vorticity generation on solid walls, are presented in detail.
文摘The Random Vortex Method extended to an azisymmetrical flow is used in the study of the flow field inside pipes incorporating an orifice plate with different contraction ratios and different inlet velocity profiles. Three test-cases, each having experimental measurements available in the literature, are studied. In particular, instantaneous and average velocity fields along with the turbulent statistics for high Reynolds number flows are computed and compared to the corresponding experimental results.These comparisons show the ability and the citations of the method. The results of the numerical simulations are used in the physical analysis of the flow fields and thus allow for a better understanding of the dynamics of the flow in pipes incorporating an orifice plate.
