Performance Improvement of Multi-Blade Centrifugal Fan by Using Optimal Bionic Blade

The aim of this paper is to obtain a higher flow rate and lower noise multi-blade centrifugal fan by employing a type of optimized bionic blade. The design of experiment with orthogonal array tables is used in the optimization process. The factors of the geometric parameters of the bionic blade which selected in the present study are leading edge curvature, leading edge thickness, the leading edge angle and pressure side surface curvature. The contribution of each factor to the performance of bionic blade is investigated numerically by solving Navier-Stokes equation and FW-H equation. The pressure side surface curvature of the blade is considered as the most effective factor. Compared with the original blade, the optimal bionic blade not only improve the flow rate of multi-blade centrifugal fan, but also suppress noise occurred on the blade surface effectively. The values of the flow rate and the A-weighted sound pressure level (SPL) for the fan with optimal bionic blade are 2.75m³/s, 44.9dB(A) respectively against the initial fan of 2.55m³/s, 52.4dB(A). The optimization results demonstrate considerable improvement of the multi-blade centrifugal fan in both flow rate and A-weighted SPL when the optimized bionic blade is used.