Characteristics of Fluid Dynamics and Noise in Laminar Flow Fans (Effects of Diameter of Impeller on Characteristics)

The effects of six design parameters, the diameter of impeller, the rotational frequency, the gap of two disks, the number of disks, the clearance between casing wall and front shroud, the disk thickness on pressure coefficient were theoretically clearified over a wide range of fan flow rates and the scroll of casing, the diameter of impeller on the noise radiated from fan. The agreement between the predicted and experimental results of the pressure coefficient is satisfactory if the modified equation (3) of velocity ratio Vuth/ u = f and empirical equation (4) of Km were used. The experimental resluts show that the fluid dynamic characteristics were improved and the sound pressure level rei sen by increasing the diameter of impeller