【作者】 陈可；

【导师】 龚光彩； 汤广发；

【作者基本信息】 湖南大学 ， 供热、供燃气、通风及空调工程， 2005， 硕士

【摘要】 本文首先总结了置换通风和悬浮颗粒污染物的主要研究方面和应用现状,并对本文所要研究的对象,即关联置换通风与悬浮颗粒污染物,探讨小粒子颗粒在置换通风背景下的输运和分布规律,展开了对其特性及可行的研究方法的分析。从而指出了在采用两相流理论研究颗粒物运动的困难以及传统试验和理论方法所存在的不足,基于此,本文确立了采用数值模拟技术展开研究。针对室内颗粒流动的特征,在必要的假设和简化的基础上,对悬浮颗粒运动基本上可采用扩散方程模型进行描述,即将颗粒相看成是拟流体进行处理。 阐述了湍流模化相关问题和方法,并就小滑移拟流体模型进行了详细的描述和分析。针对室内颗粒载荷低,即可应用“单向耦合”的前提下,改进和加强了小滑移颗粒方程,使其更适宜于颗粒污染源广泛存在的室内环境。采用有限体积方法对气粒两相流的控制方程进行离散,并就与其求解相关的策略,包括网格划分和松弛因子选用原则,固体—流体耦合求解方法,边界条件的处理,迭代收敛和“物理”收敛等要素进行了分析和讨论,总结出了本课题在模拟过程中所要采用的处理方法。 基于前面章节所分析的模型和算法理论,结合实际算例(洁净室通风)对气粒两相流进行了数值模拟,并与实地测量值作了比较和分析,认为所得的数值结果忠实可信,所形成的仿真工具稳定可靠。 从顶棚排风口布置方式,对称与非对称性结构,送风口纵横比变化等通风房间主要影响因素的角度出发,数值探讨了置换通风条件下室内悬浮颗粒污染物的分布特征及其相应的流场、温度场分布,从而为置换通风在我国的优化运用及室内环境的评价和控制提供了新的方法与技术手段。更多还原

【Abstract】 The major investigation aspects and status quo of displacement ventilation and contamination of suspended particulate matter have been reviewed at the beginning. It follows the analysis of feasible investigation methods and of inherent characteristics with respect to exploring transportation and distribution law of fine particles under the background of displacement ventilation which serves as the investigation object of this paper. Thereby that concludes the complexity of two-phase flow theory in particulate motion and the inadequacy of traditional experimental and theoretical approaches. So based on discussions mentioned above, numerical modeling technique has been put into use. In consideration of the character of indoor particulate flow as well as on basis of necessary assumption and simplification, the motion of suspended particulate matter can be described by diffusion-based models, i.e., pseudo-fluid approximation of particulate phase.Summarization about relevant issues and methods of turbulence modulation, as well as expatiation about small-slip model has been made. Due to low loadings of particles indoors, i.e., under the precondition of applicability of one-way coupling, improvement has been made to small-slip particulate equation which enables the adaptablity to application in indoor environment characteristic of wide existence of particulate pollutant sources. Discretization has been made to the governing equations of two-phase flow using finite volume method. Also has been involved the analysis and discussion of relevant strategy concerning their solution, including mesh generation, relaxation factors, coupling solution of solid-fluid, boundary conditions, convergence criteria etc..Based on analyses of models and algorithms discussed in preceding chapters, numerical simulation has been carried out on a practical example, ventilation of a clean room. Compassion with in-situ test and analysis of error have been made simultaneously. Thus conclusion can be drawn that the simulation result is convincing and faithful, so the developed simulation tool is steady and reliable in the view of engineering application.From angles of distribution pattern of exhaust outlet, structure of symmetry and asymmetry, aspect ratio of supply inlet, this paper has numerically investigated the distribution characteristics of indoor suspended particulate matter and related flow and更多还原