Performance assessment of various fan ribs inside a centrifugal blower

This study aims towards the development of an optimised design of a centrifugal blower consisting of various fan ribs, based on performance assessments following changes in the shape of its internal components. Various components, such as the external cases and the rotating fan ribs placed in a variety of operating conditions, are evaluated numerically and experimentally. Evaluation is based on performance parameters, including the inlet and outlet pressures, flow rate, torque, and power of the centrifugal fan. The numerical analysis suggests that the combination of the multiple rotating frame method and the standard k-ε turbulence model was appropriate for simulation of the internal flow characteristics and for power prediction. The numerical results were compared with tests under carefully designed experimental conditions. Based on the results and depending on the exit shape of the fan, the flow rate gradually increased to a value 7% higher than the existing model. The experimental and the numerical calculation results were in good agreement, particularly at the exit boundary condition at atmospheric pressure. In addition, among the four different impellers studied, the fan type with forward-curved fan ribs was associated with the best performance, reaching a maximum flow rate of 2.2 m3/min and a torque of 0.09N⋅m.