CFD Analysis on Ventilation Characteristics of Jet Fan with Different Pitch Angle

摘要

The objective of this paper is to realize a CFD (Computational Fluid Dynamics) analysis to evaluate the ventilation characteristics of the Banana Jet Fan with different pitch angles (0 ～ 20 degrees) and to determine the optimal angle. The airflow discharged from the jet fan was the highest at α = 0° where the loss from the jet fan itself was the lowest. But the airflow of the tunnel was the highest at α = 6.0°. This is due to the significant energy loss from friction at the ceiling of the tunnel when the pitch angle of the jet fan is low (α = 0°) and significant energy loss from recirculation, rather than friction loss, when the pitch angle is high (α = 20°). Therefore, the highest level of the airflow is at α = 6.0° where the loss from both ceiling and bottom is the least. When designing the jet fan in the tunnel ventilation, these effects of airflow into the tunnel and friction loss must be considered.