Numerical study of flow and mixing processes in wastewater treatment systems**

废水处理系统中流动和混合过程的数值研究****提出的项目旨在开发一个数值模型来模拟废水处理系统中的流动和混合过程。开发的模型还将用于进行案例研究（污水处理厂吸力集管中的污泥混合）。应用的重点是流场和温度场的分布。此外，不同几何和操作条件的影响也令人感兴趣。模型和相关观察可以帮助确定系统几何形状、最佳操作条件和系统材料。应该注意的是，当污泥被加热或稀释时，大多数经验或理论公式变得无效或不那么准确，因为它们会显著影响水力性能。因此，本研究将开发和应用先进的三维数值模型，可以显著改善污水处理系统设计的实践。该研究也将具有重要的研究和学术意义，因为它可以帮助研究人员清楚地了解废水在处理系统中的流动和混合过程，这对于处理系统的合理设计和废水的合理处置至关重要。这项研究的结果将导致更有效的系统设计和显著降低成本，因为它将减少设计不确定的风险，并将增加安全边际，防止故障或废水处理不当，以及保护环境影响。**

Numerical study of flow and mixing processes in wastewater treatment systems****The proposed project aims to develop a numerical model for simulating the flow and mixing processes in wastewater treatment system. The developed model will also be employed to carry out a case study (the sludge mixing in a suction header of a wastewater treatment plant). The focus of the application is on the distribution of flow and temperature fields. In addition, the influences of different geometric and operating conditions are also of interest. The model and relevant observations can help determine the system geometry, optimal operating conditions, and system materials. It should be noted that when sludge is heated or diluted, most empirical or theoretical formulations become invalid or less accurate, as they can significantly affect the hydraulic properties. Therefore, the present study can significantly improve the practice of designing wastewater treatment systems, as it will develop and apply an advanced three-dimensional numerical model. The study will also be of important research and academic significance, as it can help the researchers obtain a clear understanding of the flow and mixing processes of wastewater in treatment systems, which is crucial for the sound design of the treatment system and proper disposal of the wastewater. The results of the research study will lead to a more efficient design of the system and significant cost reduction as it will reduce the risk of uncertainties in design and will increase the margin of safety against failure or inadequate disposal of wastewater as well as preserving the environmental effects. **