Performance Impact of Uncertain Variations of Inlet Flow for Axial Compressor Blades

Abstract

The impact of inlet flow variations on turbomachinery flow is common in the real world, resulting in undesirable performance deteriorations in engineering. The origin of performance changes and how to evaluate the changes require to be studied, which is of high significance in both academic and engineering communities. On use of CFD and the nonintrusive polynomial chaos (NIPC) method, performance impact considering the stochastic variations of inlet flow angle for a transonic compressor rotor blade is studied in the paper. A detailed grid-independent study assisted by Richardson extrapolation is firstly presented to illustrate the reliability of CFD solutions. Then the implementations of NIPC employing adaptive sparse grid are introduced. Performance uncertainty quantification of NASA Rotor 67 is evaluated using NIPC and the effects of different distributions of inlet flow angle variation (IFAV), different ranges of IFAV on the performance changes at different operation conditions are presented. Finally, statistical analysis on flow solutions by Monte Carlo simulation is performed. The adiabatic efficiency along span at the outlet and the flow solutions in the blade passage are presented and discussed to demonstrate the impact mechanisms of IFAV.