CFD Simulation And Investigation Of Axial-Fan In Subway

As axial-fans are main devices for ventilation in subway, the technical indexessuch as flow rate, pressure and efficiency for axial-fan in subway receive greatattention in the design. Currently, the design of axial-fan in subway depends mainlyon experimental data, which is of high cost. Alternatively, simulating the internalflow properly with numerical method can provide computational results in guiding thedesign and help us to choose the best design plan. Such effort is worthwhile since itgreatly reduces the design cost. In this thesis we simulate and analyze the flow field ofaxial-fan in subway with a commercial CFD software——Fluent 6.0. Under the assumptions of steadiness, we simulate the flow field of axial-fan insubway with k－ε standard model and SIMPLE method. The diameter of this fan is1.8m. Our discussions focus on reverse flow region in suction area, pressuredistribution, velocity distribution and vector filed. The calculation results show goodagreement with the data taken from experiment. Furthermore, we rotate the brackets and simulate the flow field for each bracketangle. By analyzing the flow field and total efficiency, we find out the rule of bracketangle affecting technical indexes:Once the brackets rotate, the total efficiency ofaxial-fan under the blades' standard-rotation will decrease, while the total efficiencyof axial-fan under the blades' reverse-rotation will increase. If the bracket-rotationangel is small enough, the total efficiency of axial-fan under the blades'reverse-rotation will increase greatly, at the same time the total efficiency of axial-fanunder the blades' standard-rotation will not decrease obviously. In addition, this thesis is meaningful in many aspects such as: how to create andsimplify complex model, how to create grids and how to choose best calculationmodel for different models.