Junwei Hu, Guoliang Ding. Effect of deflecting ring on noise generated by outdoor set of a split-unit air conditioner. International Journal of Refrigeration, 2006, 29 (3): 505-513

Abstract
In order to analyze the influence of the deflecting ring on the noise generated by the outdoor set of a split-unit air conditioner, the flow field in the outdoor set is simulated with the CFD software STAR-CD, the relative turbulent intensities are computed and the influence of the width and contoured duct of the deflecting ring on the noise generated by the outdoor set is analyzed. The results of computation and experiment show that there is an optimal width of the deflecting ring, corresponding to the minimum noise generated by the outdoor set. In addition, the influence of the contoured duct of the deflecting ring on the noise generated by the outdoor set is analyzed and a double contoured duct is designed. The results of computation and experiment verify that the deflecting ring with double contoured duct can improve the aerodynamic performance and reduce the noise generated by the outdoor set.
Keywords: Noise; Air-conditioner; Deflecting ring;  Outdoor set;  Relative turbulent intensity