This paper sets up a complete CO2 contact angle test system by a visualization autoclave, uses the hanging drop-method respectively getting the advancing angle and receding angle of CO2, on the shale surface under the...This paper sets up a complete CO2 contact angle test system by a visualization autoclave, uses the hanging drop-method respectively getting the advancing angle and receding angle of CO2, on the shale surface under the different temperature, and uses the Snake method measuring contact angle of droplet images, to make the wettability experimental study for CO2 on the shale surface. According to contact angle data, wettability of CO2 on the shale surface is preferable; the temperature is the higher, the wettability is better. At the same time, by analyzing correspondingly with scanning electron microscope images of shale sample, it is obtained that shale with different surface structures has affected wettability of CO2.展开更多
Concrete structures in an alternate wetting-drying area often suffer from severe chloride ion ingress more than those in other areas. Field tests of marine structures were conducted, and chloride concentration is foun...Concrete structures in an alternate wetting-drying area often suffer from severe chloride ion ingress more than those in other areas. Field tests of marine structures were conducted, and chloride concentration is found to reach a maximum value at a certain elevation. The surface concentration and diffusion coefficient of chloride ions at different elevations exhibit Gaussian unimodal curve distributions. Using the chloride ion unsaturated permeability model, the distribution regularity mechanism is analyzed. Finally, an improved indoor accelerated simulation experiment is proposed to simulate the rules governing chloride ion ingress into concrete structures in an alternate wetting-drying area.展开更多
In this paper,a "macroscopic-scale" numerical method for drop oscillation in AC electrowetting is presented.The method is based on a high-fidelity moving mesh interface tracking(MMIT) approach and a "mi...In this paper,a "macroscopic-scale" numerical method for drop oscillation in AC electrowetting is presented.The method is based on a high-fidelity moving mesh interface tracking(MMIT) approach and a "microscopic model" for the moving contact line.The contact line model developed by Ren et al.[Phys Fluids,2010,22:102103] is used in the simulation.To determine the slip length in this model,we propose a calibration procedure using the experimental data of drop spreading in DC electrowetting.In the simulation,the frequency of input AC voltage varies in a certain range while the root-mean-square value remains fixed.The numerical simulation is validated against the experiment and it shows that the predicted resonance frequencies for different oscillation modes agree reasonably well with the experiment.The origins of discrepancy between simulation and experiment are analyzed in the paper.Further investigation is also conducted by including the contact angle hysteresis into the contact line model to account for the "stick-slip" behavior.A noticeable improvement on the prediction of resonance frequencies is achieved by using the hysteresis model.展开更多
基金Fund project： This Paper is funded by the National Natural Science Foundation of China （NO. 51076170）.
文摘This paper sets up a complete CO2 contact angle test system by a visualization autoclave, uses the hanging drop-method respectively getting the advancing angle and receding angle of CO2, on the shale surface under the different temperature, and uses the Snake method measuring contact angle of droplet images, to make the wettability experimental study for CO2 on the shale surface. According to contact angle data, wettability of CO2 on the shale surface is preferable; the temperature is the higher, the wettability is better. At the same time, by analyzing correspondingly with scanning electron microscope images of shale sample, it is obtained that shale with different surface structures has affected wettability of CO2.
基金supported by the National Natural Science Foundation of China (Grant No. 50920105806)the National Science and Technology Support Project (Grant Nos. 2006BAJ03A04, 2006BAJ03A02)
文摘Concrete structures in an alternate wetting-drying area often suffer from severe chloride ion ingress more than those in other areas. Field tests of marine structures were conducted, and chloride concentration is found to reach a maximum value at a certain elevation. The surface concentration and diffusion coefficient of chloride ions at different elevations exhibit Gaussian unimodal curve distributions. Using the chloride ion unsaturated permeability model, the distribution regularity mechanism is analyzed. Finally, an improved indoor accelerated simulation experiment is proposed to simulate the rules governing chloride ion ingress into concrete structures in an alternate wetting-drying area.
基金supported by the Chinese Academy of Sciences(Grant Nos. KJCX-SW-L08,KJCX2-YW-H18 and KJCX3-SYW-S01)the National Basic Research Program of China(Grant No.2007CB814803)the National Natural Science Foundation of China(Grant Nos.10732090,10872201 and 11023001)
文摘In this paper,a "macroscopic-scale" numerical method for drop oscillation in AC electrowetting is presented.The method is based on a high-fidelity moving mesh interface tracking(MMIT) approach and a "microscopic model" for the moving contact line.The contact line model developed by Ren et al.[Phys Fluids,2010,22:102103] is used in the simulation.To determine the slip length in this model,we propose a calibration procedure using the experimental data of drop spreading in DC electrowetting.In the simulation,the frequency of input AC voltage varies in a certain range while the root-mean-square value remains fixed.The numerical simulation is validated against the experiment and it shows that the predicted resonance frequencies for different oscillation modes agree reasonably well with the experiment.The origins of discrepancy between simulation and experiment are analyzed in the paper.Further investigation is also conducted by including the contact angle hysteresis into the contact line model to account for the "stick-slip" behavior.A noticeable improvement on the prediction of resonance frequencies is achieved by using the hysteresis model.
