Radiative heat flux at wall boundaries is important for its thermal design.Numerical methods based on structured grids are becoming trendy due to their simplicity and efficiency.Existing radiative transfer equation so...Radiative heat flux at wall boundaries is important for its thermal design.Numerical methods based on structured grids are becoming trendy due to their simplicity and efficiency.Existing radiative transfer equation solvers produce oscillating radiative heat flux at the irregular boundary if they are based on structured grids.Reverse Monte Carlo method and analytical discrete ordinates method are adopted to calculate the radiative heat flux at complex boundaries.The results show that the reverse Monte Carlo method can generate a smooth radiative heat flux profile and it is smoother with larger energy bundles.The results from the analytical discrete ordinates method show that the fluctuations are due to the ray effect.For the total or the mean radiative heat flux,the results from the analytical discrete ordinates method are very close to those from the reverse Monte Carlo method.展开更多
Almost all intraplate caprocks experienced strong deformation during the convergence of microplates, and then disintegrated into many secondary geologic units with the special characters, such as irregular boundaries ...Almost all intraplate caprocks experienced strong deformation during the convergence of microplates, and then disintegrated into many secondary geologic units with the special characters, such as irregular boundaries and particular structural assemblages. In order to understand the formation mechanism of these special phenomena, a rheological experiment on the structural scenery of the Tongling area is carried out. The result shows that the primary regular and uniform boundaries of the Tongling area becomes irregular because of the enclosing and confinement of surrounding geological units in the process of 'compression-shearing-rotation-drag'; simultaneously, two specific 'drag depressions' developed at two opposite corners of the block. The former and the later phenomena can be regarded as a typical regional-scale rheological effect and necessary outcome of intraplate deformation respectively.展开更多
To predict complicated three dimensional flow, a modified K-ε turbulence model is derived. The governing equations of turbulent flow over irregular boundary are developed by analyzing the solid-liquid two- phase the...To predict complicated three dimensional flow, a modified K-ε turbulence model is derived. The governing equations of turbulent flow over irregular boundary are developed by analyzing the solid-liquid two- phase theoretical flow model. And a perilal- cell parameter is introduced to treat irregular boundary. It shows curved boundaries and internal obstacles or islands. A simple but powerful method is described that is based on the concept of a fractional volume of fluid (VOF). This method is shown tO be efficient to track complicated free surfaces.It shows that the program established can simulate almost all kinds of turbulent flow in hydraulic engineering.展开更多
The turbulence flow Free Surface has important applications in hydraulic spillways structure, such as the hydraulic jump, energy dissipation flow etc. This is being considered as very complicated flow, and has not yet...The turbulence flow Free Surface has important applications in hydraulic spillways structure, such as the hydraulic jump, energy dissipation flow etc. This is being considered as very complicated flow, and has not yet been solved quite well by numerical method. In this paper, a Large-scale computational software package are developed for numerical laboratory of hydraulic spillway structure. Some methods,such as turbulence model, free surface and irregular boundary treating techniques,scientific computer visualization are put forward and performed.展开更多
基金Project supported by the Startup Foundation for Introducing Talent of Nanjing University of Information Science and Technology,the Anhui Provincial Natural Science Foundation,China(Grant No.2008085ME151)the National Natural Science Foundation of China(Grant Nos.51976057 and 51827808).
文摘Radiative heat flux at wall boundaries is important for its thermal design.Numerical methods based on structured grids are becoming trendy due to their simplicity and efficiency.Existing radiative transfer equation solvers produce oscillating radiative heat flux at the irregular boundary if they are based on structured grids.Reverse Monte Carlo method and analytical discrete ordinates method are adopted to calculate the radiative heat flux at complex boundaries.The results show that the reverse Monte Carlo method can generate a smooth radiative heat flux profile and it is smoother with larger energy bundles.The results from the analytical discrete ordinates method show that the fluctuations are due to the ray effect.For the total or the mean radiative heat flux,the results from the analytical discrete ordinates method are very close to those from the reverse Monte Carlo method.
文摘Almost all intraplate caprocks experienced strong deformation during the convergence of microplates, and then disintegrated into many secondary geologic units with the special characters, such as irregular boundaries and particular structural assemblages. In order to understand the formation mechanism of these special phenomena, a rheological experiment on the structural scenery of the Tongling area is carried out. The result shows that the primary regular and uniform boundaries of the Tongling area becomes irregular because of the enclosing and confinement of surrounding geological units in the process of 'compression-shearing-rotation-drag'; simultaneously, two specific 'drag depressions' developed at two opposite corners of the block. The former and the later phenomena can be regarded as a typical regional-scale rheological effect and necessary outcome of intraplate deformation respectively.
文摘To predict complicated three dimensional flow, a modified K-ε turbulence model is derived. The governing equations of turbulent flow over irregular boundary are developed by analyzing the solid-liquid two- phase theoretical flow model. And a perilal- cell parameter is introduced to treat irregular boundary. It shows curved boundaries and internal obstacles or islands. A simple but powerful method is described that is based on the concept of a fractional volume of fluid (VOF). This method is shown tO be efficient to track complicated free surfaces.It shows that the program established can simulate almost all kinds of turbulent flow in hydraulic engineering.
文摘The turbulence flow Free Surface has important applications in hydraulic spillways structure, such as the hydraulic jump, energy dissipation flow etc. This is being considered as very complicated flow, and has not yet been solved quite well by numerical method. In this paper, a Large-scale computational software package are developed for numerical laboratory of hydraulic spillway structure. Some methods,such as turbulence model, free surface and irregular boundary treating techniques,scientific computer visualization are put forward and performed.
