Abstract
Many air conditioners use fan systems for heat exchange. Vibratory motion and noise in the conditioner occur when aerodynamic force of the rotating fan blades act on the cabinet of the air conditioner. On the other hand, reaction force corresponding to the aerodynamic force occur, and then the reaction force transmitted to the motor-feet. Finally, these transmitted forces excite support-structure of the motor. In this research, we conducted experiments and discussed the influence of the number of boards which corresponds to the cabinet of an outdoor air conditioning unit to motor-reaction forces. Furthermore, we applied bell mouth to the experimental apparatus and investigated the influence of it. We also performed a computational fluid dynamics (CFD) analysis using fluid flow analysis software PHOENICS, and obtained pressure distribution near fan. Based on the calculation results of pressure distribution, experimental results were considered.
