| The current demands for three dimensions viscous flow in turbo machinery are more and more treated. This thesis presents a computational study of the flow field generated in a centrifugal fan and how that flow field changes through the downstream stator vane. Specifically, the effect that the fan flow field had on the gas-solid two-phase flow in the centrifugal fan was studied. This thesis presents the results of computational simulations done in parallel with experimental simulations of the centrifugal fan flow field. In comparisons of computational predictions with experimental data, reasonable agreement of the two-phase flow and general trends were found. The computational predictions of the centrifugal fan flow indicated that the turbulence model under-predicted gas-solid two-phase flows.On the basis of analyzing the theory of gas-solid two-phase flow, the paper put forward two ways of lightening the erosion of centrifugal fan from the point of view of initiative preventing erosion: changing fan's inlet and changing fan's impeller. This paper made three contrast experiments on changing fan's inlet, analyzed the preventing erosion theory of each experiment and the improvement degree of the erosion of fan's impeller and vanes. Meanwhile, the paper simulated the inner three-dimensional flow field of centrifugal fan with RNG k-s model, using commercial CFD software ?FLUENT. This paper also made CFD researches on the means of changing fan's impeller, analyzed the inner flow field of fan's impeller and the change of particle's track. The result of experiment research and CFD research indicated that two preventing erosion measures of centrifugal fan were able to lighten effectively the erosion of centrifugal fan. The paper offered two good ways for initiative preventing erosion of centrifugal fan.
|
PDF Full Text Request