Parametric Design and Numerical Simulation of an Electronically Commutated Motor Fan Impeller using Incidence Angle Modifications

Nowadays, electronically commutated (EC) fans are an ideal option for air handling systems because they provide advantages such as reduced energy consumption, high efficiency over a broader range of operating points, and low operating noise. This study presents a numerical investigation and parameterization of the impeller design of an EC mixed-flow fan using steady-state computational analysis and a ۲k factorial design of experiments (DOE) technique. The methodology integrates parametric design with numerical simulations to identify the optimal point. In this study, four parameters which have a significant impact on the aerodynamic performance of impeller are selected as design variables. The design variables are leading and trailing edge (LE, TE) incidence angles at both hub and shroud. The flow analysis is performed by solving Reynolds Averaged Navier Stokes (RANS) equations with the shear-stress transport (SST) turbulence model employed. By performing a set of ۱۶ simulations on different designs, an optimal point is obtained, for which the efficiency is highest. The internal flow field of the impeller, having optimized angle values, is compared with a reference model. Optimizing incidence angles helped to reduce flow separation, which is a common phenomenon inside the blade passage of fans. Numerous flow characteristics comparisons were performed to identify flow separation. It is determined from the flow analysis that there were energy losses due to separation at hub LE and TE in the reference model. The incidence angle modification improved the quality of flow leaving the impeller. The optimized model achieved an increase of ۱۰.۵۱% in efficiency and ۳.۴۸% increment in static pressure as compared to reference model. Performance curves are generated by testing the optimized model under different flow rates. Dimensionless coefficients are used as a benchmark to compare the performance of both models at design and off-design flow conditions.

کلیدواژه ها:

Electronically commutated fan impeller ، Numerical analysis ، Design of experiments ، Flow physics ، Fan performance curves