Electrowetting technology,a microfluidic technology,has attracted more and more attention in recent years and has broad prospects in terms of microdroplet drive.In this paper,the dynamic contact angle theory is used t...Electrowetting technology,a microfluidic technology,has attracted more and more attention in recent years and has broad prospects in terms of microdroplet drive.In this paper,the dynamic contact angle theory is used to develop a numerical model to predict the droplet dynamic contact behavior and internal flow field under electrowetting.In particular,based on the established computational model of droplet force balance,the dynamic process of a droplet under electrowetting is analyzed,including the perspective of pressure variation and force balance inside the droplet.The results show that when the alternating current frequency increases from 50 Hz to 500 Hz,the amplitude of the oscillation waveform after droplet stabilization is 0.036 mm,0.016 mm,0.013 mm and 0.002 mm,while the relevant droplet oscillation period T is 11 ms,4 ms,2 ms and 1 ms,respectively.It is also found that the initial phase angle does not affect the droplet oscillation amplitude.In addition,the pressure on the droplet surface under alternating current electrowetting increases rapidly to the maximum value with resonant waveform oscillation,and the droplet will present different resonance modes under voltage stimulation.The higher the resonance mode is,the smaller the droplet oscillation amplitude is and the streamline at the interface will present an eddy current,in which the number of vortices matches the resonance mode.A high resonance mode corresponds to a small droplet amplitude,while there are more vortices with a smaller size.展开更多
为了探究由光伏光热(PV/T)驱动的双热质耦合加湿除湿海水淡化系统的水电综合性能,基于能量与质量守恒原理构建了PV/T组件与加湿除湿系统的数学模型,揭示了液气比对系统相关热力学参数的影响规律,对比分析了不同顶温条件下系统的热力学性...为了探究由光伏光热(PV/T)驱动的双热质耦合加湿除湿海水淡化系统的水电综合性能,基于能量与质量守恒原理构建了PV/T组件与加湿除湿系统的数学模型,揭示了液气比对系统相关热力学参数的影响规律,对比分析了不同顶温条件下系统的热力学性能,并在某典型天气状况下探究了逐时辐照度对系统性能的综合影响。研究结果表明:热容比为1对应的液气比大小是系统的最佳性能点,此时系统造水比(GOR)与产水量均达到最大值,产电量取得最小值;当顶温为60℃时,系统产电量与产水量的极值分别为481.13 k W·m^(-2)和43.10 kg·h^(-1);系统产水性能随顶温的升高而增强。当顶温从55?C升高到60和65℃时,系统最大产水量分别增加了34.5%和68.06%,三种顶温条件下的最大GOR分别为1.31、1.56和1.71。展开更多
基金the Natural Science Foundation of Jiangsu Province (Grant No.BK2020194)the Basic Research Fund of Central University (Grant No.NS2022026)the Graduate Research and Practice Innovation Program (Grant No.xcxjh20220215)。
文摘Electrowetting technology,a microfluidic technology,has attracted more and more attention in recent years and has broad prospects in terms of microdroplet drive.In this paper,the dynamic contact angle theory is used to develop a numerical model to predict the droplet dynamic contact behavior and internal flow field under electrowetting.In particular,based on the established computational model of droplet force balance,the dynamic process of a droplet under electrowetting is analyzed,including the perspective of pressure variation and force balance inside the droplet.The results show that when the alternating current frequency increases from 50 Hz to 500 Hz,the amplitude of the oscillation waveform after droplet stabilization is 0.036 mm,0.016 mm,0.013 mm and 0.002 mm,while the relevant droplet oscillation period T is 11 ms,4 ms,2 ms and 1 ms,respectively.It is also found that the initial phase angle does not affect the droplet oscillation amplitude.In addition,the pressure on the droplet surface under alternating current electrowetting increases rapidly to the maximum value with resonant waveform oscillation,and the droplet will present different resonance modes under voltage stimulation.The higher the resonance mode is,the smaller the droplet oscillation amplitude is and the streamline at the interface will present an eddy current,in which the number of vortices matches the resonance mode.A high resonance mode corresponds to a small droplet amplitude,while there are more vortices with a smaller size.
文摘为了探究由光伏光热(PV/T)驱动的双热质耦合加湿除湿海水淡化系统的水电综合性能,基于能量与质量守恒原理构建了PV/T组件与加湿除湿系统的数学模型,揭示了液气比对系统相关热力学参数的影响规律,对比分析了不同顶温条件下系统的热力学性能,并在某典型天气状况下探究了逐时辐照度对系统性能的综合影响。研究结果表明:热容比为1对应的液气比大小是系统的最佳性能点,此时系统造水比(GOR)与产水量均达到最大值,产电量取得最小值;当顶温为60℃时,系统产电量与产水量的极值分别为481.13 k W·m^(-2)和43.10 kg·h^(-1);系统产水性能随顶温的升高而增强。当顶温从55?C升高到60和65℃时,系统最大产水量分别增加了34.5%和68.06%,三种顶温条件下的最大GOR分别为1.31、1.56和1.71。
