A packing of the complete directed symmetric graph DK v with m circuits, denoted by ( v,m) DCP, is defined to be a family of arc disjoint m circuits of DK v such that any one arc of DK v \ occurs...A packing of the complete directed symmetric graph DK v with m circuits, denoted by ( v,m) DCP, is defined to be a family of arc disjoint m circuits of DK v such that any one arc of DK v \ occurs in at most one m circuit. The packing number P(v,m) is the maximum number of m circuits in such a packing. The packing problem is to determine the value P(v,m) for every integer v≥m. In this paper, the problem is reduced to the case m+6≤v≤2m- 4m-3+12 , for any fixed even integer m≥4 . In particular, the values of P(v,m) are completely determined for m=12 , 14 and 16.展开更多
Random packed beds have more complex interior structure than structured beds and are widely used in industry and engineering. CFD simulation was carried out to investigate and analyze the local flow and heat transfer ...Random packed beds have more complex interior structure than structured beds and are widely used in industry and engineering. CFD simulation was carried out to investigate and analyze the local flow and heat transfer in a 120-sphere random packed bed. 3D Navier-Stokes equation was solved with a finite volume formulation based on the Chimera meshing technique. Investigation was focused on low Reynolds number flow （Re=4.6-56.2）, which typically occurs in packed bed reactors in bio-chemical fields. Detailed temperature field information was obtained. Inhomogeneity of flow and heat transfer due to the non-uniform distribution of void fraction was discussed and analyzed.展开更多
文摘A packing of the complete directed symmetric graph DK v with m circuits, denoted by ( v,m) DCP, is defined to be a family of arc disjoint m circuits of DK v such that any one arc of DK v \ occurs in at most one m circuit. The packing number P(v,m) is the maximum number of m circuits in such a packing. The packing problem is to determine the value P(v,m) for every integer v≥m. In this paper, the problem is reduced to the case m+6≤v≤2m- 4m-3+12 , for any fixed even integer m≥4 . In particular, the values of P(v,m) are completely determined for m=12 , 14 and 16.
基金supported financially by the Shanghai Pujiang Program (07pj14072)the Shanghai Leading Academic Disci-pline Project (J05051)
文摘Random packed beds have more complex interior structure than structured beds and are widely used in industry and engineering. CFD simulation was carried out to investigate and analyze the local flow and heat transfer in a 120-sphere random packed bed. 3D Navier-Stokes equation was solved with a finite volume formulation based on the Chimera meshing technique. Investigation was focused on low Reynolds number flow （Re=4.6-56.2）, which typically occurs in packed bed reactors in bio-chemical fields. Detailed temperature field information was obtained. Inhomogeneity of flow and heat transfer due to the non-uniform distribution of void fraction was discussed and analyzed.
