This paper proposes a hybrid vertex-centered fi- nite volume/finite element method for solution of the two di- mensional （2D） incompressible Navier-Stokes equations on unstructured grids. An incremental pressure fra...This paper proposes a hybrid vertex-centered fi- nite volume/finite element method for solution of the two di- mensional （2D） incompressible Navier-Stokes equations on unstructured grids. An incremental pressure fractional step method is adopted to handle the velocity-pressure coupling. The velocity and the pressure are collocated at the node of the vertex-centered control volume which is formed by join- ing the centroid of cells sharing the common vertex. For the temporal integration of the momentum equations, an im- plicit second-order scheme is utilized to enhance the com- putational stability and eliminate the time step limit due to the diffusion term. The momentum equations are discretized by the vertex-centered finite volume method （FVM） and the pressure Poisson equation is solved by the Galerkin finite el- ement method （FEM）. The momentum interpolation is used to damp out the spurious pressure wiggles. The test case with analytical solutions demonstrates second-order accuracy of the current hybrid scheme in time and space for both veloc- ity and pressure. The classic test cases, the lid-driven cavity flow, the skew cavity flow and the backward-facing step flow, show that numerical results are in good agreement with the published benchmark solutions.展开更多
Um Solimate emerald deposit is a unique example for the well-known beryl-related schist type.Where,the Be-mineralization is restricted to NNE-trending quartz veins/lenses and as disseminated emerald grains within the ...Um Solimate emerald deposit is a unique example for the well-known beryl-related schist type.Where,the Be-mineralization is restricted to NNE-trending quartz veins/lenses and as disseminated emerald grains within the altered-metasomatic zones of phlogopite-and graphite-schists.The study of fluid inclusions for the mineralized quartz vein revealed three major groups:(i)aqueous(H_(2)O-NaCl),(ii)aqueous-carbonic(H_(2)O-CO_(2)-[CH_(4)]-NaCl),and(iii)aqueous-hydrocarbonic(H_(2)O-CH_(4))FIs.They have been further classified into five types(namely:types 1,2,3,4 and 5)according to number of phases at the room temperature(20℃)as well as microthermometric measurements.Based upon the study of fluid inclusions,the initial-ore forming fluid was supposed to be of magmatic nature,characterized by a relatively high temperature of homogenization(T_(h,tot):269–485℃)and higher salinity(8.4 wt.%–9.6 wt.%NaCl equiv.),followed by development of aqueous-carbonic inclusions at lower temperature(T_(h,tot):241–355℃)and lower salinity(3.3 wt.%–4.9 wt.%NaCl equiv.)through metamorphic dehydration/decarbonation.Methane-rich FIs were suggested to be formed as a result of local re-equilibration of graphite in reduced environment at the contact aureole of the felsic intrusion.The P-T conditions of ore formation were estimated as modal temperature between(330–370℃)and fluid pressures of about 200 MPa,corresponding to an estimated depth ranges from 7 to 10 km.The formation of emerald is closely associated with multiple events through the ore evolution,the deposition is ascribed to destabilization process of continuous metasomatic interactions and elemental substitutions between felsic-derived Be-bearing fluids with the adjacent mafic-ultramafic rocks at the zone of mineralization.展开更多
基金supported by the Natural Science Foundation of China (11061021)the Program of Higher-level talents of Inner Mongolia University (SPH-IMU,Z200901004)the Scientific Research Projection of Higher Schools of Inner Mongolia(NJ10016,NJ10006)
文摘This paper proposes a hybrid vertex-centered fi- nite volume/finite element method for solution of the two di- mensional （2D） incompressible Navier-Stokes equations on unstructured grids. An incremental pressure fractional step method is adopted to handle the velocity-pressure coupling. The velocity and the pressure are collocated at the node of the vertex-centered control volume which is formed by join- ing the centroid of cells sharing the common vertex. For the temporal integration of the momentum equations, an im- plicit second-order scheme is utilized to enhance the com- putational stability and eliminate the time step limit due to the diffusion term. The momentum equations are discretized by the vertex-centered finite volume method （FVM） and the pressure Poisson equation is solved by the Galerkin finite el- ement method （FEM）. The momentum interpolation is used to damp out the spurious pressure wiggles. The test case with analytical solutions demonstrates second-order accuracy of the current hybrid scheme in time and space for both veloc- ity and pressure. The classic test cases, the lid-driven cavity flow, the skew cavity flow and the backward-facing step flow, show that numerical results are in good agreement with the published benchmark solutions.
基金conducted through post-doctoral fellowship scheme granted by “TüB?TAK 2221 ” fellowship in Turkey
文摘Um Solimate emerald deposit is a unique example for the well-known beryl-related schist type.Where,the Be-mineralization is restricted to NNE-trending quartz veins/lenses and as disseminated emerald grains within the altered-metasomatic zones of phlogopite-and graphite-schists.The study of fluid inclusions for the mineralized quartz vein revealed three major groups:(i)aqueous(H_(2)O-NaCl),(ii)aqueous-carbonic(H_(2)O-CO_(2)-[CH_(4)]-NaCl),and(iii)aqueous-hydrocarbonic(H_(2)O-CH_(4))FIs.They have been further classified into five types(namely:types 1,2,3,4 and 5)according to number of phases at the room temperature(20℃)as well as microthermometric measurements.Based upon the study of fluid inclusions,the initial-ore forming fluid was supposed to be of magmatic nature,characterized by a relatively high temperature of homogenization(T_(h,tot):269–485℃)and higher salinity(8.4 wt.%–9.6 wt.%NaCl equiv.),followed by development of aqueous-carbonic inclusions at lower temperature(T_(h,tot):241–355℃)and lower salinity(3.3 wt.%–4.9 wt.%NaCl equiv.)through metamorphic dehydration/decarbonation.Methane-rich FIs were suggested to be formed as a result of local re-equilibration of graphite in reduced environment at the contact aureole of the felsic intrusion.The P-T conditions of ore formation were estimated as modal temperature between(330–370℃)and fluid pressures of about 200 MPa,corresponding to an estimated depth ranges from 7 to 10 km.The formation of emerald is closely associated with multiple events through the ore evolution,the deposition is ascribed to destabilization process of continuous metasomatic interactions and elemental substitutions between felsic-derived Be-bearing fluids with the adjacent mafic-ultramafic rocks at the zone of mineralization.
