| Summary: | 碩士 === 國立臺北科技大學 === 能源與冷凍空調工程系碩士班 === 97 === Because both power consumption and noise of refrigerating-showcase condenser are large, the development of fan with energy saving and low noise is the future trend. In addition, the traditional forward engineering for product development is a time-consuming and cost-spending method. Therefore, the purpose of this study is to develop an integrating reverse engineering technique for an airfoil condenser fan, which combines the computational fluid dynamics (CFD) analysis and experimental measurement, and to help the industry to enhance the speed of product manufacture and production of energy saving and low noise fan. The research method adopted in this study is as follows. First, a reverse engineering is utilized to create a CAD drawing file of origin flat-type fan hardware. Second, an adaptive airfoil cross section replacing the flat-type one at different radii is used to build a new airfoil fan CAD file without changing the original fan size. Third, the CFD software FLUENT is employed to simulate the airflow passing through both airfoil-type and flat-type fan systems. The predicting performance curves of fans obtained from the CFD simulation results are analyzed and compared. Four, then an airfoil-section fan is manufactured according to the resultant airfoil-section profile and then is experimentally investigated. In comparing the simulation results with the experimental data, changing the aerofoil shape step-by-step until the differences between predicted and experimental results are accepted. Finally, a CNC mill following the eventual CAD drawing file is applied to build a stainless steel mold for mass produce.
It was found that to create a high performance airfoil fan with same size as the original non-airfoil one by integrating reversed engineering technology is feasible. The results show that the sound pressure level (SPL) on type 622 blade-cutting based fan is lower than the original one about 1.2 dB (A), in practical, and the values of characteristic curve(P-Q curve) for type 682 blade-cutting based fan is larger than the original one about 5%.
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