2Kawaguchi K, Kadota S, Suzuki M, et al. Study on Low-Noise Fan (Noise Reduction of Pusher-Type Condenser Cooling Fan). Transaction of JSME, Series B., 1993, 59(558): 453-459.
3Zheng Z M, Sato S, Kinoshita K. Experimental Study on Low Noise Propeller Fans (Noise Reduction by Carving Dimples on Suction Sides of Blades). ASME Fluids Engineering Division Conference, 1996, 237(2): 61-67.