Gas–liquid flow in serpentine microchannel with different surface properties exhibits drastically different flow behavior. With water and air as working fluids, the method of numerical simulation was adopted in this ...Gas–liquid flow in serpentine microchannel with different surface properties exhibits drastically different flow behavior. With water and air as working fluids, the method of numerical simulation was adopted in this paper based on CLSVOF(coupled level set and volume of fluid method) multiphase model. After verifying the reasonability of the model through experiment, by changing wall properties and Re number(Re<1500), the influences of contact angle and surface roughness on flow regime and Po number were discussed. Moreover, the difference of pressure drop between curve and straight microchannel was also calculated. Beyond that, the combined effect of curve channel and wall properties on flow resistance was analyzed. This paper finds that wall properties have great influence on gas–liquid flow in microchannels not only on flow regime but also flow characteristics. Meanwhile, the pressure drop in curve microchannels is larger than straight. It is more beneficial for fluid flowing when the straight part of microchannel is hydrophilic smooth wall and curve part is hydrophobic with large roughness.展开更多
The relationship between viscosity/yield stress and flotation rate in different chalcopyrite and lizardite concentrations was investigated by zeta potential measurements,rheological tests,flotation experiments,and Der...The relationship between viscosity/yield stress and flotation rate in different chalcopyrite and lizardite concentrations was investigated by zeta potential measurements,rheological tests,flotation experiments,and DerjguinLandau-Verwey-Overbeek theoretical calculation.Results indicated that the concentration of minerals would affect the viscosity and yield stress of the slurry.That is,the viscosity/yield stress in the slurry rises accordingly when the concentration of minerals increases.The increase in viscosity/yield stress in slurry is also unfavorable to the enrichment of chalcopyrite but is conducive to the entrainment of lizardite in either single or binary system.Specifically,the flotation rate of chalcopyrite decreases while that of lizardite increases with the rise in viscosity/yield stress.展开更多
文摘Gas–liquid flow in serpentine microchannel with different surface properties exhibits drastically different flow behavior. With water and air as working fluids, the method of numerical simulation was adopted in this paper based on CLSVOF(coupled level set and volume of fluid method) multiphase model. After verifying the reasonability of the model through experiment, by changing wall properties and Re number(Re<1500), the influences of contact angle and surface roughness on flow regime and Po number were discussed. Moreover, the difference of pressure drop between curve and straight microchannel was also calculated. Beyond that, the combined effect of curve channel and wall properties on flow resistance was analyzed. This paper finds that wall properties have great influence on gas–liquid flow in microchannels not only on flow regime but also flow characteristics. Meanwhile, the pressure drop in curve microchannels is larger than straight. It is more beneficial for fluid flowing when the straight part of microchannel is hydrophilic smooth wall and curve part is hydrophobic with large roughness.
基金Project(2018TP1002)supported by the Key Laboratory of Hunan Province for Clean and Efficient Utilization of Strategic Calcium-containing Mineral Resources,ChinaProject(2019zzts994)supported by the Central South University Graduate Research and Innovation Project,China。
文摘The relationship between viscosity/yield stress and flotation rate in different chalcopyrite and lizardite concentrations was investigated by zeta potential measurements,rheological tests,flotation experiments,and DerjguinLandau-Verwey-Overbeek theoretical calculation.Results indicated that the concentration of minerals would affect the viscosity and yield stress of the slurry.That is,the viscosity/yield stress in the slurry rises accordingly when the concentration of minerals increases.The increase in viscosity/yield stress in slurry is also unfavorable to the enrichment of chalcopyrite but is conducive to the entrainment of lizardite in either single or binary system.Specifically,the flotation rate of chalcopyrite decreases while that of lizardite increases with the rise in viscosity/yield stress.
