| Summary: | 碩士 === 中原大學 === 機械工程學系 === 87 === The purpose of the proposed research is to use PHOENICS and GENTRA CFD software package in order to make the required calculations, and to study the particle deposition rate on turbulent particle flowing a parallel channel with repeated roughness ribs. Fluid flow in the channel is modeled as a two-dimensional turbulent flow, with turbulent transport described by the modified low Reynolds number turbulent model, and the particle trajectories is predicted by using Lagrangian approach with stochastic dispersion. The important parameters include geometry, and nondimensional particle relaxation time. Get the particle deposition concentration and deposition velocity with the particle trajectories. The major findings are : (1)The size of recirculation region has related with the ratio of roughness height and channel width(h/D), but hasn*t related with the ratio of pitch and roughness height(p/h). (2)Whether reattachment point does exist or not, it hasn*t related with h/D, only has related with p/h. (3)As the same h/D, the quantity of particle deposition which is close to ribs region increasing with increasing p/h. As the same p/h, the quantity of particle deposition increasing with increasing h/D. (4)The nondimensional particle deposition velocity increasing with increasing the channel wall length. At the same channel width, the nondimensional particle deposition velocity increasing with decreasing the roughness height.
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