Investigations on static aeroelastic problems of transonic fans based on fluid-structure interaction method

Fan blades of high bypass ratio gas turbine engines are subject to substantial aerodynamic and centrifugal loads, producing the well-known phenomenon of blade untwist. Accurate fan blade shape prediction is very crucial for high-performance aero-engine. In order to investigate the effects of static aeroelastic deflections on aerodynamic performances, a time domain two-way fluid-structure interaction method was applied to simulate the deflection of NASA Rotor 67 fan blades under different operating conditions. This paper pays attention to the deviation of fan profile and aerodynamic performance due to the varying aerodynamic loads, especially for off-design conditions. The results show that the static aeroelastic deflection has a 1.8% impact on the total pressure ratio under near stall condition, and a 1.7% impact on the choke mass flow rate, relative to the cold configuration. Thus, the blade design in industrial practice should adopt a two-way fluid-structure interaction method to consider the influence of static aeroelastic problems on aerodynamic performance.