Numerical Simulation Of Influence Of Displacement Ventilation On Distribution Of Suspended Particulate Matter

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...