Due to the variation of the blade cross-section, the deformation stress and strain of the workpiece keep changing during the rolling process and the conventional rolling theory is no longer valid. The complexity and d...Due to the variation of the blade cross-section, the deformation stress and strain of the workpiece keep changing during the rolling process and the conventional rolling theory is no longer valid. The complexity and diversity of the blade cross-section determine it impossible to establish an universal theoretical model for the rolling process. Finite element analysis(FEA) provides a perspective solution to the prediction. The FEA software DEFORM was applied to discovering the deformation, stress, strain and velocity field of the variable cross-section workpiece, and the effects of friction coefficient and rolling speed during the rolling process. which indicates that the average rolling force at friction coefficient of 0.4 is 6.5% higher than that at 0.12, and the rolling velocity has less effect on the equivalent stress and strain distribution, which would confer instructive significance on the theoretical study as well as the engineering practice.展开更多
In this study, we attempt the analysis of the passage flow in the centrifugal impeller using FEM with/without the turbulence model, and compare this result with the experimental result. The turbulence model is the low...In this study, we attempt the analysis of the passage flow in the centrifugal impeller using FEM with/without the turbulence model, and compare this result with the experimental result. The turbulence model is the low Reynolds k-ε model proposed by Chien. We use the GSMAC method for the Reynolds averaged Navier-Stokes equstions, the Euler explicit method for the transport equations of the turbulent kinetic energy and the dissipation rate. All equations are discretized by the Galerkin’s method. At the midpassage of the centrifugal impeller the passagewise velocity component tends to increase in the pressure-to-suction direction, and the other component toward the pressure surface tends to be large in the region of the middle blade-to-blade to the hub side. The tip leakages appear around the region of the middle blade-to-blade near the casing together with the secondary flow toward the suction surface. These phenomena correspond with the experimental result, qualitatively.展开更多
基金Project(F12-256-1-00)supported by the Key Laboratory Program of Shenyang City,ChinaProject(N090403006)supported by the Seed Cultivation Fund,ChinaProject supported by the Research Innovation Fund for Young Teachers,China
文摘Due to the variation of the blade cross-section, the deformation stress and strain of the workpiece keep changing during the rolling process and the conventional rolling theory is no longer valid. The complexity and diversity of the blade cross-section determine it impossible to establish an universal theoretical model for the rolling process. Finite element analysis(FEA) provides a perspective solution to the prediction. The FEA software DEFORM was applied to discovering the deformation, stress, strain and velocity field of the variable cross-section workpiece, and the effects of friction coefficient and rolling speed during the rolling process. which indicates that the average rolling force at friction coefficient of 0.4 is 6.5% higher than that at 0.12, and the rolling velocity has less effect on the equivalent stress and strain distribution, which would confer instructive significance on the theoretical study as well as the engineering practice.
文摘In this study, we attempt the analysis of the passage flow in the centrifugal impeller using FEM with/without the turbulence model, and compare this result with the experimental result. The turbulence model is the low Reynolds k-ε model proposed by Chien. We use the GSMAC method for the Reynolds averaged Navier-Stokes equstions, the Euler explicit method for the transport equations of the turbulent kinetic energy and the dissipation rate. All equations are discretized by the Galerkin’s method. At the midpassage of the centrifugal impeller the passagewise velocity component tends to increase in the pressure-to-suction direction, and the other component toward the pressure surface tends to be large in the region of the middle blade-to-blade to the hub side. The tip leakages appear around the region of the middle blade-to-blade near the casing together with the secondary flow toward the suction surface. These phenomena correspond with the experimental result, qualitatively.
