Numerical optimization of a stator blade to enhance aerodynamic performance in a transonic fan stage

In this study, the stator geometry of a single-stage transonic fan was optimized to improve its aerodynamic performance. Steady and unsteady simulations were performed on the transonic fan stage to maximize the efficiency and stall margin. In a transonic fan stage, the rotor blade generates different shock waves at various operating points. When the operating condition is changed from the design point to the stall point, the passage shock wave moves upstream, leading to a change in the location of flow separation on the suction surface of the rotor blade toward the upstream. This results in a larger rotor wake near the stall and complicates the stator inlet flow after interaction between the rotor and stator blade. In this study, an optimal geometry of the stator blade is proposed to improve the aerodynamic performance and stall margin of the fan stage. The central composite face-centered method as the design of experiment was used to sample the test cases, and the response surface method was applied to find the optimal case. The transient blade row-time transformation model was applied as an unsteady simulation approach. The optimized fan was found to increase the efficiency at the near-stall point and the stall margin by 0.24 % and 0.36 %, respectively.