Research On Modular Design Of Axial Fan

The precision of manufacturing is low when the whole impeller of axial fan is cast and this method is also easy to produce flaws. According to different functions, this dissertation divides the axial fan into two parts:the blade and the hub, and makes the blade as the general module, using the standard blade to design axial fan. And I do some reaches on the hub ratio, the determination of the standard blade angle and the design pressure of the standard blade.At first, this dissertation introduces the improved variable circulation designing method, Using this method, I design some axial fans basing on different design parameters and structure parameters and then simulate the performances of these axial fans. By comparison, we find that there is an inverse correlation between pressure and efficiency of axial fan. Therefore we have to make some sacrifice on the fan efficiency when we design axial fan with high pressure. During the modular design of fan, the standard has to work in axial fans with different hub ratios. And we find that the fan efficiency gets low when the hub ratio is oversize. Therefore, considering the fan structure and aerodynamic performance, we should choose the small hub ratio.We need determine the blade angle when the standard blade matches the hub. We propose a method to determine blade angle——using geometry optimization. In addition, this dissertation does some researches on the design pressure of the standard fan and selects low pressure and medium pressure as the design pressure to design blades. Two blades have close performances in the fan with the diameter of800mm, but the medium-pressure blade has better performance in the larger size fan. Finally, we get the performance spectrum of the modular fans basing the standard blade we design.