The two-phase flow structure and particle dispersion for a dilute particle-laden jet in crossflow （JICF） were experimentally investigated by means of Phase Doppler Anemometry （PDA） measurement. The two-phase flow ...The two-phase flow structure and particle dispersion for a dilute particle-laden jet in crossflow （JICF） were experimentally investigated by means of Phase Doppler Anemometry （PDA） measurement. The two-phase flow experiments were conducted for different flow conditions and solid particle parameters, including the ratio of the jet velocity to crossflow velocity, the particle size and mass loading. The experimental results indicate that the fine particles with the size of 70 micron and the mass loading of 0.05% have a minor influence on the mean and fluctuation velocity fields of the two-phase JICF. However, the fine particle transport by the two-phase JICF is dominantly and preferentially affected by the shear layer vortices and exhibits a somewhat enhanced dispersion as compared to the fluid. For the coarse particles with the particle size ranging from 300 micron to 700 micron and the mass loading less than 0.16%, the effect of the particle parameters on the fluid phase is associated with both the anisotropic properties of the flow field and the trajectory deviation of the settling particles from the fluid. Compared to the single-phase JICF, the two-phase JICF laden with the coarse particles is recognized to possess more pronounced mean velocity alteration and turbulence modulation of the fluid phase in the presence of the particles with the larger particle size and higher mass loading.展开更多
Seasonal variation of the Tianjin coastal atmospheric aerosol opticalproperties are important for improving the atmosphere correction precision of marinesatellite and learning the environment of the boundary between t...Seasonal variation of the Tianjin coastal atmospheric aerosol opticalproperties are important for improving the atmosphere correction precision of marinesatellite and learning the environment of the boundary between the Bohai Sea and theland. In this paper, the aerosol optical data of Tianjin coastal area from April 2010 toMay 2011 were observed by using the CE317 Solar Photometer, and the aerosol opticalproperties were analyzed. The results show that: Aerosol Optical Thickness (AOT)spectra are basically in accord with Angstrom relationship; there are three basic typesof AOT daily variations, which are rising type, levelling type, and declining type; inTianjin Coastland, the mean value of AOT is highest in autumn, which is 0.686. Thevalue is lower in spring and summer, and hits the lowest point in winter. Angstromexponent α increases successively from spring, summer, autumn to winter. Due to thedusty, the angstrom exponent α in spring is lowest, the mean of which is 0.854.Compared with Qingdao Coastland, the atmospheric aerosol optical properties presentcharacteristics of regionality.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos.10572084,10972134)the Specialized Research Fund for the Doctoral Program of Higher Education (Grant No.20050280008)
文摘The two-phase flow structure and particle dispersion for a dilute particle-laden jet in crossflow （JICF） were experimentally investigated by means of Phase Doppler Anemometry （PDA） measurement. The two-phase flow experiments were conducted for different flow conditions and solid particle parameters, including the ratio of the jet velocity to crossflow velocity, the particle size and mass loading. The experimental results indicate that the fine particles with the size of 70 micron and the mass loading of 0.05% have a minor influence on the mean and fluctuation velocity fields of the two-phase JICF. However, the fine particle transport by the two-phase JICF is dominantly and preferentially affected by the shear layer vortices and exhibits a somewhat enhanced dispersion as compared to the fluid. For the coarse particles with the particle size ranging from 300 micron to 700 micron and the mass loading less than 0.16%, the effect of the particle parameters on the fluid phase is associated with both the anisotropic properties of the flow field and the trajectory deviation of the settling particles from the fluid. Compared to the single-phase JICF, the two-phase JICF laden with the coarse particles is recognized to possess more pronounced mean velocity alteration and turbulence modulation of the fluid phase in the presence of the particles with the larger particle size and higher mass loading.
基金supported by Science Foundation for The Excellent Youth Scholars of Tianjin
文摘Seasonal variation of the Tianjin coastal atmospheric aerosol opticalproperties are important for improving the atmosphere correction precision of marinesatellite and learning the environment of the boundary between the Bohai Sea and theland. In this paper, the aerosol optical data of Tianjin coastal area from April 2010 toMay 2011 were observed by using the CE317 Solar Photometer, and the aerosol opticalproperties were analyzed. The results show that: Aerosol Optical Thickness (AOT)spectra are basically in accord with Angstrom relationship; there are three basic typesof AOT daily variations, which are rising type, levelling type, and declining type; inTianjin Coastland, the mean value of AOT is highest in autumn, which is 0.686. Thevalue is lower in spring and summer, and hits the lowest point in winter. Angstromexponent α increases successively from spring, summer, autumn to winter. Due to thedusty, the angstrom exponent α in spring is lowest, the mean of which is 0.854.Compared with Qingdao Coastland, the atmospheric aerosol optical properties presentcharacteristics of regionality.
