Unsteady blade loading with clocking in Multistage Axial Compressors, Part 2

This two-part paper presents numerical and experimental investigations of clocking effects of stator blade rows on the blade loading in the third stage of the four-stage low-speed research compressor at Technische Universität Dresden. In Part 1 (Müller, L., Mailach, R., Vogeler, K., Jia, H. X., and Xi, G., "Unsteady Blade Loading with Clocking in Multistage Axial Compressors, Part 1,"Journal of Propulsion and Power, Vol. 26, No. 1,2009, pp. 25-35.) of the paper, the results of the numerical investigations are presented. The unsteady flowfield of the four-stage lowspeed research compressor at several clocking configurations is investigated using a three-dimensional time-accurate viscous solver. The unsteady pressure distributions on the rotor and stator blades in the third stage at midspan at several clocking configurations are presented and discussed. Furthermore, the clocking effects in the rotor blade tip region will also be discussed. In Part 2, the experimental investigations are analyzed, which were performed using time-resolving piezoresistive miniature pressure sensors. The measurements were carried out on the pressure side and suction side of the rotor and stator blades in the first and third stages at midspan. Exemplary results for the third stage and design point will be discussed both for the numerical and experimental investigations.