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
In virtue of reference Cartesian coordinates, geometrical relations of spatial curved structure are presented in orthogonal curvilinear coordinates. Dynamic equations for helical girder are derived by Hamilton princip...In virtue of reference Cartesian coordinates, geometrical relations of spatial curved structure are presented in orthogonal curvilinear coordinates. Dynamic equations for helical girder are derived by Hamilton principle. These equations indicate that four generalized displacements are coupled with each other. When spatial structure degenerates into planar curvilinear structure, two generalized displacements in two perpendicular planes are coupled with each other. Dynamic equations for arbitrary curvilinear structure may be obtained by the method used in this paper.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.
基金the National Natural Science Foundation of China(No.10532070)
文摘In virtue of reference Cartesian coordinates, geometrical relations of spatial curved structure are presented in orthogonal curvilinear coordinates. Dynamic equations for helical girder are derived by Hamilton principle. These equations indicate that four generalized displacements are coupled with each other. When spatial structure degenerates into planar curvilinear structure, two generalized displacements in two perpendicular planes are coupled with each other. Dynamic equations for arbitrary curvilinear structure may be obtained by the method used in this paper.
