Dynamic modeling and numerical simulation of hydrate slurry flow behavior are of great importance to offshore hydrate management.For this purpose, a dynamic model of hydrate agglomeration was proposed in this paper.Ba...Dynamic modeling and numerical simulation of hydrate slurry flow behavior are of great importance to offshore hydrate management.For this purpose, a dynamic model of hydrate agglomeration was proposed in this paper.Based on population balance equation, the frame of the dynamic model was established first, which took both hydrate agglomeration and hydrate breakage into consideration.Then, the calculating methods of four key parameters involved in the dynamic model were given according to hydrate agglomeration dynamics.The four key parameters are collision frequency, agglomeration efficiency, breakage frequency and the size distribution of sub particles resulting from particle breakage.After the whole dynamic model was built, it was combined with several traditional solid–liquid flow models and then together solved by the CFD software FLUENT 14.5.Finally, using this method, the influences of flow rate and hydrate volume fraction on hydrate particle size distribution, hydrate volume concentration distribution and pipeline pressure drop were simulated and analyzed.展开更多
运用地统计学方法，分析了山东省滨州地区二代棉铃虫在1965-2004年间种群动态的时间序列结构特征和自相关性，根据决定系数尺。和Akaike’s Information Criteria（AIC）判别参数，筛选出最优拟合模型。结果表明：棉铃虫越冬蛹量、二代...运用地统计学方法，分析了山东省滨州地区二代棉铃虫在1965-2004年间种群动态的时间序列结构特征和自相关性，根据决定系数尺。和Akaike’s Information Criteria（AIC）判别参数，筛选出最优拟合模型。结果表明：棉铃虫越冬蛹量、二代棉铃虫百株累计卵量、发生程度的最优拟合模型均是球形模型，呈聚集分布；三者的变程分别为10．41、12和12．06年，高度一致；三者在时间序列上的自相关性分别是53．22％、52．62％和69．06％；三者的结构特征引起的种群变异介于25％～75％，为中等程度的空间自相关性，其相关强度顺序是百株累计卵量〈越冬蛹量〈发生程度，随机部分引起的空间变异则相反。展开更多
基金Supported by Shandong Provincial Natural Science Foundation,China(ZR2017MEE057)the Fundamental Research Funds for the Central Universities(14CX02207A,17CX05006,17CX06017)the Graduate Innovation Project of China University of Petroleum(East China)(YCX2017062)
文摘Dynamic modeling and numerical simulation of hydrate slurry flow behavior are of great importance to offshore hydrate management.For this purpose, a dynamic model of hydrate agglomeration was proposed in this paper.Based on population balance equation, the frame of the dynamic model was established first, which took both hydrate agglomeration and hydrate breakage into consideration.Then, the calculating methods of four key parameters involved in the dynamic model were given according to hydrate agglomeration dynamics.The four key parameters are collision frequency, agglomeration efficiency, breakage frequency and the size distribution of sub particles resulting from particle breakage.After the whole dynamic model was built, it was combined with several traditional solid–liquid flow models and then together solved by the CFD software FLUENT 14.5.Finally, using this method, the influences of flow rate and hydrate volume fraction on hydrate particle size distribution, hydrate volume concentration distribution and pipeline pressure drop were simulated and analyzed.
文摘运用地统计学方法，分析了山东省滨州地区二代棉铃虫在1965-2004年间种群动态的时间序列结构特征和自相关性，根据决定系数尺。和Akaike’s Information Criteria（AIC）判别参数，筛选出最优拟合模型。结果表明：棉铃虫越冬蛹量、二代棉铃虫百株累计卵量、发生程度的最优拟合模型均是球形模型，呈聚集分布；三者的变程分别为10．41、12和12．06年，高度一致；三者在时间序列上的自相关性分别是53．22％、52．62％和69．06％；三者的结构特征引起的种群变异介于25％～75％，为中等程度的空间自相关性，其相关强度顺序是百株累计卵量〈越冬蛹量〈发生程度，随机部分引起的空间变异则相反。
