NUMERICAL INVESTIGATION ON IMPACT OF A FLUSH-MOUNTED AIRINTAKE EXIT DISTORTION TO THE REAR FAN PERFORMANCE

For the sake of investigating impact of inlet distortion on the fan stage performance, numerical simulation of the whole structure of a flush-mounted S-shaped inlet and the rear fan stage was conducted in this paper. The single fan stage with uniform air admission was researched at the same time for comparison. Considering substantial boundary layer ingesting, a scheme of suction control imposed at the first bend of the inlet was also carried out. The results show that the total pressure ratio as well as the efficiency of the fan stage decreases dramatically and the choked mass flow has a reduction about 1.20% as compare with the uniform air condition. With suction control, aerodynamic performance of the fan stage improves slightly, the choked mass flow and total pressure ratio at the maximum isentropic efficiency point increase about 0.28% and 0.25% respectively, and the stable operation range is extended. With effect of rotating rotor, the significant low energy region at bottom of the airintake exit decrease continually as it travels downstream to the rotor and covers nearly three flow passages at the front-edge rotor blade, moreover, the high-energy fluid mixes with the low-energy fluid.