| The axial fans are a kind of fluid machinery which have performance at a large flow, and are popularly uesed in many industries. The optimization of the axial fan design is always a favor of many fan engineers. With the development of computer technology, it is a trend that the axial fans are designed by a computer.According to the given flow rate and pressure, it is that two metro axial fans in different methods of optimization and equal circulation are designed whose vanes have different twist law. Numerical model building is finished in GAMBIT and is to divide in grids. Fluid fields of the two simulation models are calculated in FLUENT which is one of the CFD software, and then the performance parameter diagrams of the total pressure, effective power and efficiency under the total pressure with equal circulation and optimization model are given by means of changing flow rate. A contrastive analysis is taken between the diagrams and the difference of the optimization and equal circulation method is discussed to look for a better method of designing vanes. At last, an analysis of working sketch is taken about the model and is given the variability of velocity and pressure in the flow field. Not only the explanation is given about the variability of performance parameters, but also the guidelines are provided for the test in a draught and production.In the thesis, two axial fans are designed respectively with optimization and equal circulation method. The contrastive diagrams of total pressure, effective power and efficiency are given, in which it is found that a good performance with optimization method than equal circulation method in efficiency improving. Furthermore, analysing the distributing of pressure and velocity in the fan, and explaining pressure expanding of the impeller, the cylinder supposing and so on, by using the chart show. Then introducing the RNG-k-s model and MRF model within FLUENT software for the future application on flow field simulation of the fan. |
PDF Full Text Request