Almost without exception literature data and modeling effort are understandably devoted to water as the sprayed liquid since it constitutes the most common liquid used in spray drying applications. In selected applica...Almost without exception literature data and modeling effort are understandably devoted to water as the sprayed liquid since it constitutes the most common liquid used in spray drying applications. In selected applications, however, the liquid making up the solution or suspension may not be water. The objective of this work is to examine the differences in flow patterns, thermal behavior and drying rates caused by different liquids having different thermo-physical properties spray into a spray dryer using a computational fluid dynamic model.Numerical experiments were carried out for water (base case), ethyl alcohol and isopropyl alcohol-the latter two as model non-aqueous liquids. The chamber geometry was cylinder type with a co-current axial pressure nozzle and also an axial central exit so that the configuration is two dimensional and axi-symmetric. It is shown that the liquid properties can have major influence on the thermal field, droplet trajectories, residence times and overall evaporation capacity when all parameters of the problem are held fixed. Deviations from the single phase turbulent airflow in the same chamber without spray are different for the three liquids examined.展开更多
In the present paper, closed form singular solutions for an infinite anisotropic plate with an elliptic hole or crack are derived based on the Stroh-type formalism for the general anisotropic plate. With the solutions...In the present paper, closed form singular solutions for an infinite anisotropic plate with an elliptic hole or crack are derived based on the Stroh-type formalism for the general anisotropic plate. With the solutions, the hoop stresses and hoop moments around the elliptic hole as well as the stress intensity factors at the crack tip under concentrated in-plane stresses and bending moments are obtained. The singular solutions can be used for approximate analysis of an anisotropic plate weakened by a hole or a crack under concentrated forces and moments. They can also be used as fundamental solutions of boundary integral equations in BEM analysis for anisotropic plates with holes or cracks under general force and boundary conditions.展开更多
In the light of the increasingly serious I/O bottleneck problem, the paper puts forward a method named RAID-M (RAID Matrix) to build high performance mass storage from cheap PC components based on the idea of multi-ch...In the light of the increasingly serious I/O bottleneck problem, the paper puts forward a method named RAID-M (RAID Matrix) to build high performance mass storage from cheap PC components based on the idea of multi-channel I/O and parallel access. Theoretical analyses prove that different RAID-M configurations vary their performance, space utilization and reliability, meeting various application goals. Experiments show that both the sequential read performance and sequential write performance of a RAID-M prototype machine have broken through the limitation of 32 bit/33 MHz PCI bus.展开更多
文摘Almost without exception literature data and modeling effort are understandably devoted to water as the sprayed liquid since it constitutes the most common liquid used in spray drying applications. In selected applications, however, the liquid making up the solution or suspension may not be water. The objective of this work is to examine the differences in flow patterns, thermal behavior and drying rates caused by different liquids having different thermo-physical properties spray into a spray dryer using a computational fluid dynamic model.Numerical experiments were carried out for water (base case), ethyl alcohol and isopropyl alcohol-the latter two as model non-aqueous liquids. The chamber geometry was cylinder type with a co-current axial pressure nozzle and also an axial central exit so that the configuration is two dimensional and axi-symmetric. It is shown that the liquid properties can have major influence on the thermal field, droplet trajectories, residence times and overall evaporation capacity when all parameters of the problem are held fixed. Deviations from the single phase turbulent airflow in the same chamber without spray are different for the three liquids examined.
基金Project supported by the National Natural Science Foundation of China (No. 10102019).
文摘In the present paper, closed form singular solutions for an infinite anisotropic plate with an elliptic hole or crack are derived based on the Stroh-type formalism for the general anisotropic plate. With the solutions, the hoop stresses and hoop moments around the elliptic hole as well as the stress intensity factors at the crack tip under concentrated in-plane stresses and bending moments are obtained. The singular solutions can be used for approximate analysis of an anisotropic plate weakened by a hole or a crack under concentrated forces and moments. They can also be used as fundamental solutions of boundary integral equations in BEM analysis for anisotropic plates with holes or cracks under general force and boundary conditions.
基金the National Natural Science Foundation of China(Grant No.60403043) the Doctorate Foundation of Tsinghua University.
文摘In the light of the increasingly serious I/O bottleneck problem, the paper puts forward a method named RAID-M (RAID Matrix) to build high performance mass storage from cheap PC components based on the idea of multi-channel I/O and parallel access. Theoretical analyses prove that different RAID-M configurations vary their performance, space utilization and reliability, meeting various application goals. Experiments show that both the sequential read performance and sequential write performance of a RAID-M prototype machine have broken through the limitation of 32 bit/33 MHz PCI bus.
