Structure Optimization Of Axial-flow Fan In Air-Condition Based On CFD

The axial-flow fan is extensively applied in each field such as ventilating, textile, mine, metallurgy, hydropower station. It is the main equipment of air conditioning and ventilating system. Comparing with centrifugal fan, axial-fan has the advantages like bigger air flow, lower pressure, without guide vanes etc. Currently the design of the axial-fan mainly depends on experimental data, which is of high cost. Alternatively, simulating the internal flow properly with numerical method can provide computational results in guiding the design and help us to choose the best design plan. In this thesis we simulate and analyze the flow field and aero noise of axial-fan in air-conditioning with a commercial CFD software-Fluent6 .2.Under the assumptions of steadiness, we simulate the flow field of axial-fan in subway with Realizable k-εmodel and SIMPLE method. Our discussions focus on reverse flow region in suction area, pressure distribution, velocity distribution and vector filed. The calculation results show good agreement with the data taken from experiment. After that, we set the optimization model which based on target of highest efficiency and solve the model. The optimized efficiency of axial-fan is 2.97% higher than former.Further more, we simulate the noise level of axial-fan by aeroacoustics model which is attached to Fluent 6.2 and optimize the noise level. The noise of optimized axial-fan adds only 1.72 dB when the efficiency of fan increased 3.56%. It's much better than increasing the efficiency by rev up.In addition , this thesis is meaningful in many aspects such as: how to create and simplify complex model, how to create grids and how to choose best calculation model for different models...