| Indoor environment has an important impact on human health, suspendedparticulate matter has become one of the largest pollutants,it’s harmful to humanphysical and mental health. on that account, it’s significant to study of the dispersionlaw and motion characteristics of indoor particulate matter to improve indoor airquality and to promote the healthy development of the indoor environment. Since the1960s, the numerical simulation method based on computational fluid dynamics (CFD)technology, has become a another mainstay apart from theoretical analysis andexperimental studies in fluid dynamics study areas. With the rapid development ofcomputer technology, CFD method has drawn more and more attention of researchersand design engineers.The first chapter reviewed previous work in terms of the research status of thesuspended particles, numerical simulation solution method, gas-particle multiphaseflow model predecessors and so on. it also summarizes the limitations of applyingexisting model or processing method to study the indoor fine particles, and thenproposed the content of the research project.The second chapter select the appropriate gas turbulence method and gas-particletwo-phase flow model based on comparative analysis. From numerous turbulencemodel, we choose the large-eddy model, it has a high precision and can accuratelygrasp the information of the instantaneous flow field. Meanwhile, Our research canavoid using the controversial conventional wall function method and Reynolds stressmodel, the latter need up to14empirical constants to be determine. DPM model basedon Lagrangian coordinates to be selected to calculate the particle phase, the model cantracking each real-time particle trajectory, but also avoid the difficulty that the Eulermethod need to enter excessive force parameters, empirical coefficient of collisionand so on, and thus ensure the accuracy of the calculations in the absence ofexperimental data. This chapter also introduced common wall particle collision model,as well as the near wall treatment in the LES model.The third chapter, base on the theoretical basis of the first two chapters, using theLES model base on the basis of Smagorinsky sub-grid model to calculate the airflowfield of two sets of three-dimensional model, and then compare the simulation resultswith the previous experimental data to verify this model. The numerical simulation results accurately reproduce the motion characteristics of the flow field. Comparedwith the other N-S equation Reynolds-averaged model, LES numerical simulationmethod can capture the flow field more accurately, meanwhile LES can providedetailed analysis about instantaneous information of flow field, this point is valuablein studying of the turbulent flow field.The DPM model at Lagrangian coordinates has been join in the fourth chaptersresearch base on the basis of the third chapters result, and then use this model tostudying the dispersion pattern of particulates. Assume that the particle phase onlysuffered from fluid drag force and gravity force, and selected three different walldeposit model, particles are assumed to initially be injected into zone1and uniformlydistributed in that area when the measurement started. Then following work focus onthe study of the particulate phase ’s concentration decay law in the Zone1and Zone2area, as well as different wall conditions influence on the particles attenuation law.The fifth Chapter made a summary of the full text and a outlook about task in thefuture research. |
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