| 摘要: |
| 【目的】研究氧化沟推流转轮半径对氧化沟内流场回流长度的影响，为氧化沟工艺设计提供理论依据。【方法】采用气液两相流混合模型，并选取Realizable k-ε湍流模型封闭两相流时均方程，对氧化沟水力特性进行三维数值模拟，使用压力隐式算子分裂（Pressure-Implicit with Splitting of Operators，PISO）算法对速度与压力耦合进行求解，并采用VOF（Volume of Fluid）法对自由水面进行模拟。【结果】数值模拟得到了氧化沟推流转轮半径与水流回流区长度的关系表达式，表明回流区长度和直道段长度之比与叶轮半径和小弯道半径之比呈直线关系，并通过量纲分析法对其进行了进一步验证。【结论】氧化沟水下推流转轮是水流运动的最主要动力来源，转轮半径的大小对沟道内水流的流速以及流场结构有重要影响。 |
| 关键词: 氧化沟 回流区长度 转轮半径 数值模拟 量纲分析法 |
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| 基金项目:国家自然科学基金项目“氧化沟中气液固三相混合液的数值模拟与生物反应动力学研究”（51178391）；中央财政支持地方高校发展专项资金特色重点学科项目（106-00X101） |
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| 3D numerical simulation of the influence of flow runner radius on the length of flow recirculation in an oxidation ditch |
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LIU Yu-ling,LÜ Bin,WEI Wen-li
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| Abstract: |
| 【Objective】The research on the 3D numerical simulation of the influence of flow runner radius on the length of flow recirculation in an oxidation ditch can provide a reference for design of oxidation ditches.【Method】The gas-liquid two-phase mixture model and the 3D Realizable k-ε turbulence model were used to numerically simulate the turbulence flow in an oxidation ditch,and to study the influence of flow runner size on the length of flow recirculation in an oxidation ditch.The Pressure Implicit with Splitting of Operators (PISO) algorithm was used to solve velocity and pressure.The Volume of Fluid (VOF) method was used to simulate the free surface.【Result】By the simulation research,the relation between the size of the flow runners and the length of flow recirculation was obtained and was further verified by the dimension analysis method.The ratio of flow recirculation length to the straight line segment length was linearly related to the ratio of impeller radius to small curve radius.【Conclusion】The flow runner is the main power source of power for oxidation ditches.The size of the flow runner has significantly influenced on the flow velocity and flow structure in an oxidation ditch. |
| Key words: oxidation ditch length of recirculation runner radius numerical simulation dimensional analysis |
