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Figure 10 shows the yplus at wall was consistently less than 5. FLUENT documentations mentioned that "the mesh should be made either coarse or fine enough to prevent the wall-adjacent cells from being placed in the buffer layer (yplus = 5~30)". Since the yplus from the model was consistenly less than zero and was in the region of viscous sublayer, the turbulence flow near the wall was able to be resolved properly.
Figure 11. Mesh Sensitivity Analysis
Figure 12. Reynolds Number Effect on Pressure Coefficient Drop
Figure 13. Clearance Height Effect on Pressure Coefficient Drop and Maximum Velocity
Figure 14. Effect of Turbulence Model on Pressure Coefficient Drop