This paper presents a potential approach to settle the problem of surviving major safety accidents in Submerged Floating Tunnel （SFT） that detachable emergency escape devices are set up outside SFT. The Computationa...This paper presents a potential approach to settle the problem of surviving major safety accidents in Submerged Floating Tunnel （SFT） that detachable emergency escape devices are set up outside SFT. The Computational Fluid Dynamics （CFD） technology is used to investigate the effect of emergency escape devices on the hydrodynamic load acting on SFT in uniform and oscillatory flows and water waves by numerical test. The governing equations, i.e., the Reynolds-Averaged Navier-Stokes （RANS） equations and k - ε standard turbulence equations, are solved by the Finite Volume Method （FVM）. Analytic solutions for the Airy wave are applied to set boundary conditions to generate water wave. The VOF method is used to trace the free surface. In uniform flow, hydrodynamic loads, applied to SFT with emergency escape device, reduce obviously. But, in oscillatory flow, it has little influence on hydrodynamic loads acting on SFT. Horizontal and vertical wave loads of SFT magnify to some extend due to emergency escape devices so that the influence of emergency escape devices on hydrodynamic loads of SFT should be taken into consideration when designed.展开更多
Dam breaks are easily triggered by heavy rains due to extreme weather such as typhoons,causing serious economic losses and casualties.Through the investigation of Chaoshan coastal zone,it is found that there have been...Dam breaks are easily triggered by heavy rains due to extreme weather such as typhoons,causing serious economic losses and casualties.Through the investigation of Chaoshan coastal zone,it is found that there have been dam breaks caused by geological disasters.In the design and management of water conservancy project,it is very important to analyze the effect of disastrous flow caused by dam break on the building.In this paper,the effect of the dam break flow on the cylinder is simulated numerically by taking the water body with initial velocity as the dam break flow,and the flow characteristics around the cylinder and the water body are analyzed.Numerical model adopted the Renault Average Navier-Stokes(RANS)model and volume of fluid(VOF)method to analyze the evolution of free water surface.It is found that there are different patterns of water movement in the process of dam break resulting in the creation of several isolated convex hull forms of dam-break waves on the stationary water surface,which causes longer disturbances in the water near the cylinder and makes the cylinder more vulnerable to fatigue damage.The increase of the height of the dam breaking water will lead to the increase of the hydrodynamic force on the pipeline.This study has guiding significance for the study of dam break and dam body design in water conservancy projects.展开更多
基金the China Postdoctoral Science Foundation (Grant Nos. 201003274, 20090460636)the Specialized Research Fund for the Doctoral Program of Higher Education (Grant No. 20090111120016)
文摘This paper presents a potential approach to settle the problem of surviving major safety accidents in Submerged Floating Tunnel （SFT） that detachable emergency escape devices are set up outside SFT. The Computational Fluid Dynamics （CFD） technology is used to investigate the effect of emergency escape devices on the hydrodynamic load acting on SFT in uniform and oscillatory flows and water waves by numerical test. The governing equations, i.e., the Reynolds-Averaged Navier-Stokes （RANS） equations and k - ε standard turbulence equations, are solved by the Finite Volume Method （FVM）. Analytic solutions for the Airy wave are applied to set boundary conditions to generate water wave. The VOF method is used to trace the free surface. In uniform flow, hydrodynamic loads, applied to SFT with emergency escape device, reduce obviously. But, in oscillatory flow, it has little influence on hydrodynamic loads acting on SFT. Horizontal and vertical wave loads of SFT magnify to some extend due to emergency escape devices so that the influence of emergency escape devices on hydrodynamic loads of SFT should be taken into consideration when designed.
文摘Dam breaks are easily triggered by heavy rains due to extreme weather such as typhoons,causing serious economic losses and casualties.Through the investigation of Chaoshan coastal zone,it is found that there have been dam breaks caused by geological disasters.In the design and management of water conservancy project,it is very important to analyze the effect of disastrous flow caused by dam break on the building.In this paper,the effect of the dam break flow on the cylinder is simulated numerically by taking the water body with initial velocity as the dam break flow,and the flow characteristics around the cylinder and the water body are analyzed.Numerical model adopted the Renault Average Navier-Stokes(RANS)model and volume of fluid(VOF)method to analyze the evolution of free water surface.It is found that there are different patterns of water movement in the process of dam break resulting in the creation of several isolated convex hull forms of dam-break waves on the stationary water surface,which causes longer disturbances in the water near the cylinder and makes the cylinder more vulnerable to fatigue damage.The increase of the height of the dam breaking water will lead to the increase of the hydrodynamic force on the pipeline.This study has guiding significance for the study of dam break and dam body design in water conservancy projects.
