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1.
琼州海峡潮流能资源的数值模拟评估   总被引:2,自引:1,他引:1  
近年来,我国能源消耗量不断的增长使我们更加重视可再生能源的开发利用,而我国近海拥有复杂的海岸线和广阔的大陆架,其中许多海域蕴藏着丰富的潮流能资源。潮流能资源评估则是其电站站址选择、发电量预测等工程设计的首要工作。结合两个站位的潮流实测数据,本文利用FVCOM海洋环流数值模式较好的模拟了琼州海峡潮波传播状况,分析了该海域潮流能资源水平分布规律和时间变化特征,初步估算了该水道的潮流能的理论蕴藏量,并采用FLUX方法对该水道的技术可开发量进行了评估。结果表明,琼州海峡中心海域功率密度高,两岸资源低;可能最大流速、大潮年平均最大功率密度、小潮年平均功率密度和年平均功率密度等特征值分布基本相似;其丰富区域出现在海峡东口南部海域以及海峡中部海域,其中东口南部海域可能最大流速可达4.6 m/s,表层流大潮年平均最大功率密度为5996 W/m2,小潮平均最大功率密度仅为467 W/m2,年平均功率密度为819 W/m2,代表点超过0.7 m/s的潮流流速年统计时间约为4717 h;海峡潮流能资源理论蕴藏量为189.55MW,利用FLUX、FARM、GC方法得到该水道的潮流能可开发量分别为249GW/yr、20.2GW/yr和263GW/yr。  相似文献   
2.
Sediment cores (∼40–100 cm) were collected at 12 locations in the western Bohai Bay, the Haihe River estuary, the Yongding River estuary and the Tianjin Harbor, China, during 24–26 July 2007, and analyzed for 7Be and 210Pb activities. Due to localized hydrodynamic patterns and frequent disturbance from dredging activities, steady-state sedimentation features were not observed in this study. As demonstrated in the 7Be and 210Pb profiles, the temporal and spatial variations of these radionuclides support a non-steady state depositional environment in the study area. By comparing 7Be and 210Pb inventories in the sediments with those of the atmospheric source, we found that: 1) sediments dredged from the Tianjin Harbor or eroded from nearby estuarine and coastal areas are retained in the western Bohai Bay for relatively short intervals (several months), as reflected in the relatively high 7Be inventories in the western Bohai Bay; 2) over the long-term (years to decades), 210Pb inventories in the sediments imply that there is a net on-shore transport of sediments, and the sediments are mass-balanced in the entire study area. Overall, our results suggest that the sediments are retained in the estuaries and the western Bohai Bay despite local variability in sediment dynamics and disturbance due to human activities.  相似文献   
3.
采用RANS结合4种湍流模型对低质量比单自由度涡激振动进行数值模拟,对比分析其对该问题的适用性。用四阶Runge-Kutta法离散运动方程,基于动网格技术处理圆柱振荡引起的网格运动,并对壁面条件的处理进行了细致分析。根据Williamson水槽实验,从振幅比、频率比响应、水动力系数及相位突变、尾涡模式等方面对比分析了4种模型的性能和表现,结果表明Standardκ-ω模型与实验差异较大;目前本类研究中运用较少的Realizableκ-ε模型也是可以适用于涡激振动计算的;κ-ω系列模型得到的最大振幅(0.55D)小于κ-ε系列模型的结果(0.87D);SSTκ-ω模型以及2种κ-ε模型都反映出锁定区振动频率fex与泄涡频率fst分离,其中SSTκ-ω模型较为接近实验结果;尾涡模式上,SSTκ-ω模型在各个分支与实验结果一致;总之,各种模型针对不同物理现象各有优势和缺陷。  相似文献   
4.
This paper presents a numerical model study of the propagation of water waves using the parabolic approximation of the mild-slope equation in the orthogonal coordinate system. Two types of coordinate systems are studied: (a) a general form of orthogonal coordinate system and (b) the conformal system, a special form of orthogonal coordinate system. Two typical examples, namely, expanded breakwaters and a circular channel, are studied to validate the model. First, the examples are studied by use of the general orthogonal coordinates. Then the same examples are computed by use of the confonnal system. The computational results show that the confonnal coordinate system generally gives better predictions than the general orthogonal system. A numerical technique for generating the conformal grid is combined with the numerical model to improve the practicability of the model. The comparison between the result from the numerical grid system and that from the analytical grid system shows that reliable computational results can be obtained by use of the numerical confonnal grid system.  相似文献   
5.
Sediment cores (~40–100 cm) were collected at 12 locations in the western Bohai Bay, the Haihe River estuary, the Yongding River estuary and the Tianjin Harbor, China, during 24–26 July 2007, and analyzed for 7Be and 210Pb activities. Due to localized hydrodynamic patterns and frequent disturbance from dredging activities, steady-state sedimentation features were not observed in this study. As demonstrated in the 7Be and 210Pb profiles, the temporal and spatial variations of these radionuclides support a non-steady state depositional environment in the study area. By comparing 7Be and 210Pb inventories in the sediments with those of the atmospheric source, we found that: 1) sediments dredged from the Tianjin Harbor or eroded from nearby estuarine and coastal areas are retained in the western Bohai Bay for relatively short intervals (several months), as reflected in the relatively high 7Be inventories in the western Bohai Bay; 2) over the long-term (years to decades), 210Pb inventories in the sediments imply that there is a net on-shore transport of sediments, and the sediments are mass-balanced in the entire study area. Overall, our results suggest that the sediments are retained in the estuaries and the western Bohai Bay despite local variability in sediment dynamics and disturbance due to human activities.  相似文献   
6.
海滩地表水与地下水间的相互作用对于海岸带的物质循环及生态环境有重要的影响。基于控制体的思想推导出了统一形式的地表水和地下水的控制方程,在此基础上不仅实现了地表水和地下水的全耦合模拟,也简化了动边界的处理。对一些经典算例的模拟结果验证了该模型的有效性。  相似文献   
7.
水沙环境中重金属迁移转化模型的两个解析解   总被引:2,自引:0,他引:2  
选取整体模型,将水体中的溶解态(水相)和吸附态(固相)重金属作为整体,开展了水沙环境中重金属迁移转化数学模型的解析解研究.在一定的简化条件下,得出了泥沙单纯沉积和单纯侵蚀两种特定动床条件下一维重金属迁移转化模型的两个解析解.文中成果可用于数学模型的验证和完善.  相似文献   
8.
平面二维流场中质点运动的可视化   总被引:2,自引:0,他引:2  
对平面二维流场中质点运动的可视化进行了研究,提出了一种适用于三角形非结构化网格系统中质点运动轨迹的跟踪算法,利用数值计算方法的稳定性限制条件对质点位置的搜索算法进行了优化,极大地降低了算法的时间复杂度,提高了计算效率,采用Shepard插值法求解质点的速度,四阶龙格库塔方法积分质点的运动轨迹,选用Visual Fortran语言实现了质点运动的动态显示,将本文方法与平面二维潮流模型相结合,用于渤海潮流场中质点运动规律的研究,初步得出了渤海中质点运动和水效换的一些规律。  相似文献   
9.
地理信息系统在渤海湾水体富营养化研究中的应用   总被引:1,自引:0,他引:1  
一般的关系型数据库处理近岸海域富营养化监测数据时难以同时管理数据的空间属性和一般属性,且不具有对数据进行空间分析的能力。文中以A rcG IS地理信息系统为数据管理平台,克服了一般数据库的上述缺陷。文章以渤海湾水体富营养化研究为实例,应用A rcG IS地理信息系统自身的功能对监测数据进行了空间分布特性和时间变化趋势分析及水体营养状况的评价,取得了较满意的结果。  相似文献   
10.
文章讨论了波浪场可视化实现过程中的一些关键的算法。文中针对表示波浪面的数据集的特性,采用了一种简单的节点法矢量算法。绘制结果表明,用这种简单算法取代二维和三维的数据场节点法矢量的常用算法,能够保持波浪场三维图形的光照效果。利用层次模型算法进行波浪的动态演示,比较了相同面积的波浪场在不同网格密度情况下图形的显示质量,提出波浪场图形质量有与特征波长相匹配的最佳经验网格密度。  相似文献   
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