应用计算流体动力学模型来模拟地下水流水力性能的湿地外文翻译、中英文翻译、外文文献翻译

Application of computational fluid dynamic to model the hydraulic performance of subsurface flow wetlands FAN Liwei1, Hai Reti1, , WANG Wenxing1； , LU Zexiang2, YANG Zhiming3 1. Center of Resources and Environment, Beijing University of Chemical Technology, Beijing 100029, China. E-mail: 2. State Key Laboratory of Chemical Resources Engineering, Beijing University of Chemical Technology, Beijing 100029, China 3. Department of Agriculture and Natural Resources, Delaware State University, Dover, DE 19901, USA Received 10 January 2008； revised 18 February 2008； accepted 23 May 2008 Abstract A subsurface flow wetland (SSFW) was simulated using a commercial computational fluid dynamic (CFD) code.The constructed media was simulated using porous media and the liquid resident time distribution (RTD) in the SSFW was obtained using the particle trajectory model.The effect of wetland configuration and operating conditions on the hydraulic performance of the SSFW were investigated. The results indicated that the hydraulic performance of the SSFW was predominantly affected by the wetland configuration.The hydraulic efficiency of the SSFW with an inlet at the middle edge of the upper media was 0.584 and the best among the SSFWs with an inlet at the top, the middle, and the bottom edge of the upper media.The constructed media affected the hydraulic performance by the ratio (K) of the upper and lower media resistance. The selection of appropriate media resistance in the protection layer can improve the hydraulic eciency.When the viscous resistance coefficient of the media in the protection layer changed from 2.315 10 5 to 1.200 10 8, the hydraulic efficiency of the SSFW increased from 0.301 to 0.751. However, the effect of operating conditions on the hydraulic eciency of the SSFW was slight. Key words: subsurface flow wetland； computational fluid dynamic； resident time distribution； hydraulic performance Introduction The wastewater treatment technology by subsurface flow wetland (SSFW) relies on the functions of media-microorganism-vegetable to achieve efficient removal of pollutants by a combination of physical, chemical, and biological processes. The processes of physical, chemical,and biological treatment in a wetland system depend on the flow of the water. Therefore, the hydraulic characteristics within the system have a significant effect on the efficiency of the wetland as a water treatment device (Hu, 1991；Feng and Molz, 1997； Chazarenc et al., 2003). Many wetland management problems can be attributed to poor hydrodynamic characteristics within the wetland system(Persson et al., 1999). An appropriate hydraulic design not only can improve the pollutant removal eciency but also can reduce the cost and achieve optimal benefits of treatment and engineering (Badkoubi et al., 1998； Garca et al., 2004a； Garca et al., 2005). Good engineering design demands a detailed understanding of the hydraulic characteristics within a system.Some studies have been devoted to evaluate the impact parameters of the hydrodynamic behavior of constructed wetlands， including the vegetation（ Kadlec， 1990； Jain and Harindra， 1995；serra et al., 2004）， flow parameters(Kadlec, 1994), wind (Kadlec and Knight, 1996),temperature(Torres et al., 1997), inlet and outlet location(Persson et al., 1999； Suliman et al., 2006), water depth(USEPA, 2000； Huang et al., 2005), aspect ratio, and medium (William et al., 1995； Garca et al., 2004b；Worman and Kronnas, 2005； Molle, 2006； Suliman et al.,2007). However, the hydraulics of the wetland in the above publications was studied by physical tracer experiment that is expensive, time-consuming, and even impossible to perform in the majority of practical cases. Hence, using mathematical models as design tools can contribute to a better understanding of the flow patterns in wetlands. Computational fluid dynamics (CFD) is a sophisticated design and analysis tool to simulate the flow of mass and momentum throughout a fluid continuum. It is an advantage method to study the hydraulics and reaction in a constructed wetland because it is low cost, can be used to analyze the full flow field and can be scaled up.The technique allows a computational model to be used under many dierent design constraints and is effective in water treatment device design and optimization, such as wastewater oxidation ponds (Wood et al., 1995), sedimentation tanks (Zhou and MeCorquodale, 1994； Matko et al., 1996), industrial reservoir (Ta and Brignal, 1998), and aquaculture raceway (Huggins et al., 2005). However, the flow through the filter constructed in the SSFW is different from that in the above water treatment devices. To the authors knowledge, no one has provided a CFD model for SSFWs until today. In this article,the hydraulic characteristics of an SSFW with a layer pattern constructed filter were studied by the CFD model,and the effect of wetland configuration（ the inlet location,constructed media,and protection layer） and operating conditions（ the inlet elocity（ u） and outlet pressure） on the hydraulic performance of the SSFW were discussed thoroughly.This work further investigation of the CFD simulation on the pollutant removal in SSFWs. The author；FAN Liwei1, Hai Reti1, , WANG Wenxing1； , LU Zexiang2, YANG Zhiming3 Nationality:China Source:Journal of Environmental Science（ English） 2008 12th edition Page8 应用计算流体动力学模型来模拟地下水流水力性能的湿地 FAN Liwei1, Hai Reti1, , WANG Wenxing1； , LU Zexiang2, YANG Zhiming3 1.中国 北京化工大学资源与环境中心 100029 2.中国 北京化工大学国家重点实验化学资源工程 100029 3.美国 特拉华州州立大学自然资源和农业部 19901 2008年 1月得 到 10次 修订 ， 2008年 2月 18日 收到 ,2008年 5月 23日 接受 文摘 (SSFW)是一个地下水流湿地模拟使用商业计算流体动力学 (CFD)的代码。所构造的媒体是使用多孔介质和液体常驻时间分布 (RTD)模拟 获得 SSFW 使用粒子轨迹模型。对 湿地水力性能的 SSFW 的影响配置和操作条件进行调查。结果表明 ,水力性能的主要影响 SSFW 是湿地配置。水力效率的 SSFW 与一个入口在中间的边缘上的媒体是 0.584和 是 最好的 SSFWs 中与一个入口在顶部 ,中间 ,和底部边缘上的媒体。所构造的媒体影响水力性能的比率 (K)的上部和下部媒体阻力。选择适当的媒体阻力的保护层能提高液压 eciency， 粘滞阻力系数的媒体在保护层从 2.315 10 5改变 到 1.200 10 8,液压的 SSFW 从 0.301增加 到 了 0.751， 然而 ,操作条件对液压 eciency 的 SSFW 的效果是轻微的。 关键词： 地下水流湿地 ；计算流体动力学 ；居民时间分布 ；水力性能 介绍 废水处理技术通过地下水流湿地 (SSFW)依赖于功能实现的媒体微生物蔬菜有效去除污染物的结合物理、化学和生物过程。这个过程的物理、化学和生物处理在一个湿地系统依赖于流动的水。因此 ,在系统的水力特性有显著影响效率的湿地作为水处理设备 (胡 ,1991；冯 和 Molz,1997；Chazarenc et al。 ,2003)。许多湿地管理问题可以归因于可怜的水动力特性在湿地系统 (佩尔森 et al。 ,1999)。一个适当的水力设计不仅可以改善污染物去除 eciency 但也可以降低成本 ,实现最优收益的治疗和工程(Badkoubi et al。 ,1998；Garca et al。 2004；Garca et al。 ,2005)。 良好的工程设计要求更细致的了解在一个系统的水力特性。一些研究已经致力于评估影响参数的人工湿地水动力行为 ,包括植被 (Kadlec,1990；耆那教徒和Harindra,1995；塞拉 et al。 ,2004),流参数 (Kadlec,1994),风 (Kadlec和骑士 ,1996),温度 (托雷斯 et al。 ,1997),进口和出口的位置 (佩尔森 et al。 ,1999；Suliman et al。 ,2006),水的深度 (美国环境保护局 ,2000；黄 e