Investigation Of Radial Distortion In The Axial-flow Fan By Di-actuator Theory

Axial-flow fan is one type of universal machine in industry, which is popularly used in different kinds of industrial areas. However recently because of the requirement of energy-saving and improvement of life standard, the research of the high efficiency and low noise axial fan become an important direction of research in turbo machinery.The technology of skew and swept blades was used in aviation field at first, which make the turbo machine have an improvement in aerodynamic and aero-acoustics performance. The 2D Euler through flow model Di-actuator theory is used to the research of skew and swept blades in this paper. The computation of mass center line in the arc and radial line with arc type is made by using the polar equation of circular. The modification of radial equilibrium equation is also made in the discrete scheme, iteration direction, iteration style and the criteria of convergence. In order to verify the effect of the modification, the comparison of the computational results are made with the experiment results which was made before, which show the modification make the computation results have an improvement on precision.According to the design theory of axial fan isolated airfoil theory, an axial fan whose blade is skew and swept is designed to satisfy the specific aerodynamic requirements in this paper. The flow pattern of this axial fan is variable circulation, and then the output aerodynamic performance experiment is carried on according the standard. The experiment results show clearly that the aerodynamic performance of the arc plate blade is similar to that of the airfoil blade.The numerical simulation is made on this axial fan, the process of numerical simulation is described in detail, and the computational results is given, the flow field in the axial fan is analyzed in detail.The inlet distortion has a serious influence on the aerodynamic performance and stable operation of turbo machinery. The improved Di-actuator theory is used to research the radial distortion of axial velocity at the inlet of axial fan in this paper. Different kinds of inlet velocity distribution assumptions are made, the aerodynamic performance computation is done according to these assumptions. According to the comparison of the relative errors between the computational results and experimental results, and the reasonable description of inlet distortion of axial velocity is found.