應(yīng)用計算流體動力學模型來模擬地下水流水力性能的濕地外文翻譯、中英文翻譯、外文文獻翻譯

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 應(yīng)用計算流體動力學模型來模擬地下水流水力性能的濕地 FAN Liwei1, Hai Reti1, , WANG Wenxing1； , LU Zexiang2, YANG Zhiming3 1.中國 北京化工大學資源與環(huán)境中心 100029 2.中國 北京化工大學國家重點實驗化學資源工程 100029 3.美國 特拉華州州立大學自然資源和農(nóng)業(yè)部 19901 2008年 1月得 到 10次 修訂 ， 2008年 2月 18日 收到 ,2008年 5月 23日 接受 文摘 (SSFW)是一個地下水流濕地模擬使用商業(yè)計算流體動力學 (CFD)的代碼。所構(gòu)造的媒體是使用多孔介質(zhì)和液體常駐時間分布 (RTD)模擬 獲得 SSFW 使用粒子軌跡模型。對 濕地水力性能的 SSFW 的影響配置和操作條件進行調(diào)查。結(jié)果表明 ,水力性能的主要影響 SSFW 是濕地配置。水力效率的 SSFW 與一個入口在中間的邊緣上的媒體是 0.584和 是 最好的 SSFWs 中與一個入口在頂部 ,中間 ,和底部邊緣上的媒體。所構(gòu)造的媒體影響水力性能的比率 (K)的上部和下部媒體阻力。選擇適當?shù)拿襟w阻力的保護層能提高液壓 eciency， 粘滯阻力系數(shù)的媒體在保護層從 2.315 10 5改變 到 1.200 10 8,液壓的 SSFW 從 0.301增加 到 了 0.751， 然而 ,操作條件對液壓 eciency 的 SSFW 的效果是輕微的。 關(guān)鍵詞： 地下水流濕地 ；計算流體動力學 ；居民時間分布 ；水力性能 介紹 廢水處理技術(shù)通過地下水流濕地 (SSFW)依賴于功能實現(xiàn)的媒體微生物蔬菜有效去除污染物的結(jié)合物理、化學和生物過程。這個過程的物理、化學和生物處理在一個濕地系統(tǒng)依賴于流動的水。因此 ,在系統(tǒng)的水力特性有顯著影響效率的濕地作為水處理設(shè)備 (胡 ,1991；馮 和 Molz,1997；Chazarenc et al。 ,2003)。許多濕地管理問題可以歸因于可憐的水動力特性在濕地系統(tǒng) (佩爾森 et al。 ,1999)。一個適當?shù)乃υO(shè)計不僅可以改善污染物去除 eciency 但也可以降低成本 ,實現(xiàn)最優(yōu)收益的治療和工程(Badkoubi et al。 ,1998；Garca et al。 2004；Garca et al。 ,2005)。 良好的工程設(shè)計要求更細致的了解在一個系統(tǒng)的水力特性。一些研究已經(jīng)致力于評估影響參數(shù)的人工濕地水動力行為 ,包括植被 (Kadlec,1990；耆那教徒和Harindra,1995；塞拉 et al。 ,2004),流參數(shù) (Kadlec,1994),風 (Kadlec和騎士 ,1996),溫度 (托雷斯 et al。 ,1997),進口和出口的位置 (佩爾森 et al。 ,1999；Suliman et al。 ,2006),水的深度 (美國環(huán)境保護局 ,2000；黃 e