Twin vortices flow behavior with out-of-plane angle effect in double bent pipe system is studied numerically and experimentally. Double bent pipe system generates very complicated flow behavior including twin vortices...Twin vortices flow behavior with out-of-plane angle effect in double bent pipe system is studied numerically and experimentally. Double bent pipe system generates very complicated flow behavior including twin vortices in the downstream of the double bent. Moreover, angle from the plane of the double bent forms more complicated flow behavior due to the flow twist by out-of-plane angle. In this study, numerical analysis is examined for this double bent system using three-dimensional CFD code, FLUENT, to reproduce those complicated flow behaviors with twin vortices. Numerical results are compared with experimental results obtained by Ultrasonic Velocity Profiler (UVP). Discrepancy between numerical and experimental result is discussed changing out-of- plane angle, α. Velocity profiles obtained by numerical results are converted into UVP profiles, and they are compared with the experimental results by UVP. Consequently, velocity behavior especially around the pipe wall obtained by numerical results is agreed with experimental results.展开更多
With the aid of elastic plastic large deformation finite element method （FEM）, an elastic plastic and cou pling thermo-mechanical model was built to calculate the bending process of the bent pipe, combining with loc...With the aid of elastic plastic large deformation finite element method （FEM）, an elastic plastic and cou pling thermo-mechanical model was built to calculate the bending process of the bent pipe, combining with local heating or cooling of the bent pipe. Based on the FEM simulation, the metal deformation during the bending process was analyzed in detail. The thinning and thickening ratio of the pipe wall thickness, the ovality of the cross section of the pipe and the spring back angle, etc. , are presented.展开更多
文摘Twin vortices flow behavior with out-of-plane angle effect in double bent pipe system is studied numerically and experimentally. Double bent pipe system generates very complicated flow behavior including twin vortices in the downstream of the double bent. Moreover, angle from the plane of the double bent forms more complicated flow behavior due to the flow twist by out-of-plane angle. In this study, numerical analysis is examined for this double bent system using three-dimensional CFD code, FLUENT, to reproduce those complicated flow behaviors with twin vortices. Numerical results are compared with experimental results obtained by Ultrasonic Velocity Profiler (UVP). Discrepancy between numerical and experimental result is discussed changing out-of- plane angle, α. Velocity profiles obtained by numerical results are converted into UVP profiles, and they are compared with the experimental results by UVP. Consequently, velocity behavior especially around the pipe wall obtained by numerical results is agreed with experimental results.
基金Item Sponsored by National Natural Science Foundation of China (50435010) and National"973"Project of China(2004CCA06600)
文摘With the aid of elastic plastic large deformation finite element method （FEM）, an elastic plastic and cou pling thermo-mechanical model was built to calculate the bending process of the bent pipe, combining with local heating or cooling of the bent pipe. Based on the FEM simulation, the metal deformation during the bending process was analyzed in detail. The thinning and thickening ratio of the pipe wall thickness, the ovality of the cross section of the pipe and the spring back angle, etc. , are presented.
