Optimization Design of Thin Multi-Blade Fan

抄録

In recent years, electronic devices have become smaller and denser. For example, fans mounted in steam exhaust units are required to be thinner from the standpoint of installation space, while maintaining performance. In this study, an optimization design method for thin multi-blade fans was developed by combining design of experiments, three-dimensional steady and unsteady CFD analysis, response surface methods, and optimization methods. The performance of the optimized fan obtained by this design method was verified through performance tests, and the aerodynamic loss was quantitatively evaluated by developing a loss analysis method for centrifugal fans. As a result, the total pressure coefficient of the optimized fan increased and the power coefficient decreased compared to the original fan, and the total pressure efficiency improved by about 12.7% at the best efficiency point flow rate in the experimental value. This is because the theoretical total pressure coefficient decreased due to the smaller blade outlet angle of the optimized fan compared to the original fan, while the total aerodynamic loss decreased significantly due to the decrease in casing loss, impeller loss, and impeller friction loss in the impeller.