An theoretical investigation was conducted to detect the gas-solid interface effect on laminar flow characteristics for gas flowing through micropassages. In the wall-adjacent region, the change in viscosity of fluid ...An theoretical investigation was conducted to detect the gas-solid interface effect on laminar flow characteristics for gas flowing through micropassages. In the wall-adjacent region, the change in viscosity of fluid vs the distance from the wall surface, as derived from the kinetic theory of gases result in significallt influence on the flow characteristics in micropassages. A model was proposed to account for the wall effect. Analytical expressions for velocity profiles and pressure drop were derived, respectively,for laminar fiow of gases in microtubes and in extremely narrow parallel plates. The Knudsen number,Kn, as a criterion, that the fiow can be treated reasonably as flow in macrochannels, is discussed.展开更多
The mechanism of heat transfer in a crossflow moving packed bed heat transfer exchanger is analyzed and a two dimensional heat transfer mathematical model has been developed based on the two fluid model (TFM)approach,...The mechanism of heat transfer in a crossflow moving packed bed heat transfer exchanger is analyzed and a two dimensional heat transfer mathematical model has been developed based on the two fluid model (TFM)approach, in which both phases are considered to be continuous and fully interpenetrating.This model is solved by means of numerical method and the results are approximately in agreement with the experimental ones.展开更多
文摘An theoretical investigation was conducted to detect the gas-solid interface effect on laminar flow characteristics for gas flowing through micropassages. In the wall-adjacent region, the change in viscosity of fluid vs the distance from the wall surface, as derived from the kinetic theory of gases result in significallt influence on the flow characteristics in micropassages. A model was proposed to account for the wall effect. Analytical expressions for velocity profiles and pressure drop were derived, respectively,for laminar fiow of gases in microtubes and in extremely narrow parallel plates. The Knudsen number,Kn, as a criterion, that the fiow can be treated reasonably as flow in macrochannels, is discussed.
文摘The mechanism of heat transfer in a crossflow moving packed bed heat transfer exchanger is analyzed and a two dimensional heat transfer mathematical model has been developed based on the two fluid model (TFM)approach, in which both phases are considered to be continuous and fully interpenetrating.This model is solved by means of numerical method and the results are approximately in agreement with the experimental ones.
