4123 ターボファン形状最適化自動設計技術の開発(G05-11 翼・翼列,G05 流体工学)  [in Japanese] 4123 Development of Autonomous Design Technique for a Centrifugal Fan Using Numerical Optimization  [in Japanese]

A centrifugal fan for an inner unit of an air-conditioner was designed using a system based on computational fluid dynamics (CFD) and numerical optimization. Commercial CFD software (STAR-CD) with an in-house automatic grid generator was used. A simulated annealing algorithm for numerical optimization was also used to minimize the noise level and to maximize fan efficiency. The predicted noise level was calculated from the relative velocities obtained by CFD. Calculations show that the optimized fan produced low noise and was more efficient than a conventional fan, demonstrating that the system can be used to design silent and highly efficient fan. A further finding was that there was a correlation between specific noise level and fan efficiency. This correlation shows that it is important for designing the fan to uniform distribution of relative velocity.