Numerical investigation on influence ot suction in S-shaped inlet to the rear fan-stage performance

Numerical simulations of the whole structure of the air intake and the fan stage were conducted to explore the evolution process of a half flush-mounted air intake exit distortion in the rear components. In this investigation, a scheme of suction control imposed near the throat of the inlet was carried out to realize the large boundary layer ingestion. The results indicate a slight improvement in the aerodynamic performance of the fan stage after the suc-tion, when it was operated in the prototype condition compared with the uniform air condition. The distorted region at the air intake exit decreases significantly as well. In addition, the low energy fluid gathering at the bottom cross section is decreasing while moving to the tip station of the rotor hub. Resulting in a covering about 3 blade passages at the rotor blade front edge was found in the end. Both the total pressure and velocity of the air in these distorted blade passages are lower but more after the suction than those in other passages. However, serious flow separations occur at the stator blade suction side in the influence of the large boundary ingestion in the prototype condition. And they mainly happen at the 50% span and weaken with the suction.