Faculty of Mechanical Engineering, Amirkabir University of Technology, P.O. Box 15875-4413 Tehran, I.R. IRAN
In this paper, the turbulent air droplet flow inside a single passage of a curved type vane separator has been studied numerically. The simulation is based on the Eulerian - Lagrangian method. For turbulent air flow calculations, a computer code was developed to solve the Reynolds Averaged Navier Stokes (RANS) equations together with the equations of Reynolds Stress Transport Model (RSTM) on collocated unstructured meshes. Finite volume method was applied for discretization of the gas flow equations. Also, the low Reynolds modification has been applied for RSTM and the results have been compared with those obtained by Standard RSTM. For droplet trajectory calculation, the Eddy Interaction Model (EIM) was applied to take the turbulent dispersion of droplets into account. The performance of the code has been evaluated by comparing the simulations results with experimental data. The results show that by including the wall reflection terms in transport equations of the Reynolds stresses, better predictions can be achieved than those obtained by RSTM without wall reflection terms. The enhanced wall treatments can further improve the results. Finally, the pressure loss and droplet removal efficiency for different plate spacings have been calculated using the developed codes. The numerical results show that for plate spacings in the range of 25 mm to 35 mm, the pressure loss is approximately constant. On the other hand, the increment in plate spacing reduces the droplet removal efficiency. Therefore, in the mentioned range, 25mm spacing gives the best performance for this type of the vane separator.
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