海啸灾害是最致命的海洋灾害之一,地震与火山活动引发的越洋海啸多次冲击太平洋沿岸国家(Atwater,1987)。受海啸发生物理条件的限制,对中国沿海影响较大的地震海啸主要来自马尼拉俯冲带产生的地震海啸(陈颙等,2007)。研究表明,北宋年间...海啸灾害是最致命的海洋灾害之一,地震与火山活动引发的越洋海啸多次冲击太平洋沿岸国家(Atwater,1987)。受海啸发生物理条件的限制,对中国沿海影响较大的地震海啸主要来自马尼拉俯冲带产生的地震海啸(陈颙等,2007)。研究表明,北宋年间马尼拉俯冲带地震引发的海啸波传播到南海沿岸地区(Sun et al.,2013;杨文卿等,2019;王喻鸣等,2023)。展开更多
A hydrodynamic model of liquid-solid circulating fluidized bed is proposed to predict the slip velocity between fluid and solid particles and bed voidage by applying the theory of two-phase flow.The slip velocity can ...A hydrodynamic model of liquid-solid circulating fluidized bed is proposed to predict the slip velocity between fluid and solid particles and bed voidage by applying the theory of two-phase flow.The slip velocity can be represented by the following equation.u s =u-v=(1-ε)(ρ p -ρ f )g+F p -(1-ε)F f /εβ/εExperiments were carried out by using water and ceramic spheres,1.43 and 3.06 mm in mean diameter in a circulating fluidized bed of 31 mm diameter and 1700 mm height.The voidage was from 0.96 to 1,and the ratio between superficial liquid velocity and particle terminal velocity varied from 1.22 to 10.1 in the experiments.The fluid-particle interphase drag coefficient in the model was correlated from experimental data as followsd p βρ f =0.1881(1-ε) 1.0089 UU t -0.8043 d p D t -0.3228 The predicted values by the model proposed agreed with the experimental data well.In the meantime,the variation of slip velocity with superficial liquid velocity,bed voidage and particle diameter was discussed.The results showed that the model in the paper can well predict the hydrodynamics of liquid-solid two-phase flow in circuiating fluidized bed.The model is suitable for liquid-solid circulating fluidized bed under high flow rate and low concentration and can be also used on each tube in liquid-solid circulating fluidized bed heat exchanger.展开更多
文摘海啸灾害是最致命的海洋灾害之一,地震与火山活动引发的越洋海啸多次冲击太平洋沿岸国家(Atwater,1987)。受海啸发生物理条件的限制,对中国沿海影响较大的地震海啸主要来自马尼拉俯冲带产生的地震海啸(陈颙等,2007)。研究表明,北宋年间马尼拉俯冲带地震引发的海啸波传播到南海沿岸地区(Sun et al.,2013;杨文卿等,2019;王喻鸣等,2023)。
文摘A hydrodynamic model of liquid-solid circulating fluidized bed is proposed to predict the slip velocity between fluid and solid particles and bed voidage by applying the theory of two-phase flow.The slip velocity can be represented by the following equation.u s =u-v=(1-ε)(ρ p -ρ f )g+F p -(1-ε)F f /εβ/εExperiments were carried out by using water and ceramic spheres,1.43 and 3.06 mm in mean diameter in a circulating fluidized bed of 31 mm diameter and 1700 mm height.The voidage was from 0.96 to 1,and the ratio between superficial liquid velocity and particle terminal velocity varied from 1.22 to 10.1 in the experiments.The fluid-particle interphase drag coefficient in the model was correlated from experimental data as followsd p βρ f =0.1881(1-ε) 1.0089 UU t -0.8043 d p D t -0.3228 The predicted values by the model proposed agreed with the experimental data well.In the meantime,the variation of slip velocity with superficial liquid velocity,bed voidage and particle diameter was discussed.The results showed that the model in the paper can well predict the hydrodynamics of liquid-solid two-phase flow in circuiating fluidized bed.The model is suitable for liquid-solid circulating fluidized bed under high flow rate and low concentration and can be also used on each tube in liquid-solid circulating fluidized bed heat exchanger.
