With the development of rural economy, pollutions of rural sewage are in- creasingly serious. This paper introduces the characteristics of rural domestic sewage and the rural sewage treatment situation, and according ...With the development of rural economy, pollutions of rural sewage are in- creasingly serious. This paper introduces the characteristics of rural domestic sewage and the rural sewage treatment situation, and according to the problems of funds, management, process selection, policy and weak awareness of environmental protection in the rural domestic sewage treatment, puts forward relevant countermea- sures to ensure long-term operation of sewage treatment system, and achieve the purpose of improving rural water environment and protect the ecological environment in rural areas.展开更多
With the intermediate flow states predicted by local two phase Riemann problem,the modified ghost fluid method(MGFM)and its variant(r GFM)have been widely employed to resolve the interface condition in the simulation ...With the intermediate flow states predicted by local two phase Riemann problem,the modified ghost fluid method(MGFM)and its variant(r GFM)have been widely employed to resolve the interface condition in the simulation of compressible multi-medium flows.In this work,the drawback of the construction procedure of local two phase Riemann problem in r GFM was investigated in detail,and a refined version of the construction procedure was specially developed to make the simulation of underwater explosion bubbles more accurate and robust.Beside the refined r GFM,the fast and accurate particle level set method was also adopted to achieve a more effective and computationally efficient capture of the evolving multi-medium interfaces during the simulation.To demonstrate the improvement brought by current refinement,several typical numerical examples of underwater explosion bubbles were performed with original r GFM and refined r GFM,respectively.The results indicate that,when compared with original r GFM,numerical oscillations were effectively removed with the proposed refinement.Accordingly,with present refined treatment of interface condition,a more accurate and robust simulation of underwater explosion bubbles was accomplished in this work.展开更多
文摘With the development of rural economy, pollutions of rural sewage are in- creasingly serious. This paper introduces the characteristics of rural domestic sewage and the rural sewage treatment situation, and according to the problems of funds, management, process selection, policy and weak awareness of environmental protection in the rural domestic sewage treatment, puts forward relevant countermea- sures to ensure long-term operation of sewage treatment system, and achieve the purpose of improving rural water environment and protect the ecological environment in rural areas.
基金supported by the National Natural Science Foundation of China(Grant Nos.041322062 and 51075004)the Foundation of Zhejiang Educational Committee(Grant No.529003+G21144)
文摘With the intermediate flow states predicted by local two phase Riemann problem,the modified ghost fluid method(MGFM)and its variant(r GFM)have been widely employed to resolve the interface condition in the simulation of compressible multi-medium flows.In this work,the drawback of the construction procedure of local two phase Riemann problem in r GFM was investigated in detail,and a refined version of the construction procedure was specially developed to make the simulation of underwater explosion bubbles more accurate and robust.Beside the refined r GFM,the fast and accurate particle level set method was also adopted to achieve a more effective and computationally efficient capture of the evolving multi-medium interfaces during the simulation.To demonstrate the improvement brought by current refinement,several typical numerical examples of underwater explosion bubbles were performed with original r GFM and refined r GFM,respectively.The results indicate that,when compared with original r GFM,numerical oscillations were effectively removed with the proposed refinement.Accordingly,with present refined treatment of interface condition,a more accurate and robust simulation of underwater explosion bubbles was accomplished in this work.