采用CLSVOF (coupled level set and volume of fluid)方法,以空气和水为介质对矩形截面蛇形微通道内弹状流流动传热进行模拟研究。改变气液相流速,探讨了沿程局部Nu数的变化情况;改变接触角及相对粗糙度,分析其对微通道传热的影响;比...采用CLSVOF (coupled level set and volume of fluid)方法,以空气和水为介质对矩形截面蛇形微通道内弹状流流动传热进行模拟研究。改变气液相流速,探讨了沿程局部Nu数的变化情况;改变接触角及相对粗糙度,分析其对微通道传热的影响;比较不同形貌粗糙元对微通道传热特性的影响;最后,基于Design-Expert平台,对蛇形微通道进行了优化设计。计算结果表明,与单相流动相比,弹状流可以强化传热,且局部Nu数随气弹的出现呈周期性变化;无滑移壁面条件下,疏水壁面一定程度上阻碍传热;粗糙壁面微通道可强化换热,且合理布置的随机粗糙元传热效果最好。展开更多
The penetration depth and concentration distribution of implanted ions have been studied for low energy heavy ions implanted in the dry seeds of plant, such as peanut, mung beau, sunflower, wheat and radish seeds, etc...The penetration depth and concentration distribution of implanted ions have been studied for low energy heavy ions implanted in the dry seeds of plant, such as peanut, mung beau, sunflower, wheat and radish seeds, etc. by SEM+EDS. The results .how that the maximum penetration depth is about 12μm for V+ with an energy 200 keV implanted in cotyledon of the peanut, 18pm, spin, 20μm for V2+ with 90 keV implanted in sunflower, wheat, radish seeds, respectively. The penetration depth of implanted Cu2+ with 80 keV is about 90μm in the remainder funicle derivative of the mung beau seeds. The experimental result of the maximum penetration depth of implanted V+ in the peanut seeds was compared with the calculated value of the TRIM95.展开更多
文摘采用CLSVOF (coupled level set and volume of fluid)方法,以空气和水为介质对矩形截面蛇形微通道内弹状流流动传热进行模拟研究。改变气液相流速,探讨了沿程局部Nu数的变化情况;改变接触角及相对粗糙度,分析其对微通道传热的影响;比较不同形貌粗糙元对微通道传热特性的影响;最后,基于Design-Expert平台,对蛇形微通道进行了优化设计。计算结果表明,与单相流动相比,弹状流可以强化传热,且局部Nu数随气弹的出现呈周期性变化;无滑移壁面条件下,疏水壁面一定程度上阻碍传热;粗糙壁面微通道可强化换热,且合理布置的随机粗糙元传热效果最好。
基金the National Natural Science Foundation (No. 19890303)
文摘The penetration depth and concentration distribution of implanted ions have been studied for low energy heavy ions implanted in the dry seeds of plant, such as peanut, mung beau, sunflower, wheat and radish seeds, etc. by SEM+EDS. The results .how that the maximum penetration depth is about 12μm for V+ with an energy 200 keV implanted in cotyledon of the peanut, 18pm, spin, 20μm for V2+ with 90 keV implanted in sunflower, wheat, radish seeds, respectively. The penetration depth of implanted Cu2+ with 80 keV is about 90μm in the remainder funicle derivative of the mung beau seeds. The experimental result of the maximum penetration depth of implanted V+ in the peanut seeds was compared with the calculated value of the TRIM95.
