Aerodynamic design and numerical validation of highly loaded fan

The preliminary aerodynamic design of an inlet fan stage was validated by numerical simulation. The inlet fan stage was designed to produce a total pressure ratio of 2.4 and loading coefficient of 0.42 at tip speed of 480 m/s.The design difficulty of rotor tip and stator hub was analyzed. Some design parameters were especially assessed, such as inlet swirl angle, design pressure ratio, rotor pre-shock Mach number, inlet Mach number and outlet angle of stator. The boundary layer bleeding at stator hub and its' mechanism were discussed. It is concluded that conventional rotor has capability to attain the loading coefficient of 0.42; the inlet flow near the stator hub is supersonic under such loading level and strong normal shock exists in hub passage of stator; the normal shock spreads through the hub passage and incurs severe separation stall even though the diffusion factor is low.