Investigation of unsteady profile pressure based on the decomposition of characteristic waveform

Numerical simulations of the three-dimensional unsteady viscous flow field of three cases, R/S/R case with unequal rotor blade numbers, R/S case and clocking case, were performed at design point. The data from R/S/R were analyzed to find out the influence, which drives the static pressure fluctuated with time on the stator blade surface; the data from the clocking case were investigated to understand the period of unsteady pressure fluctuation and conclude the relationship between the static pressure fluctuation and clocking positions; the R/S case was employed to obtain the influence from upstream rotor. The results show that the amount of the rotors' blade decided the period of the static pressure fluctuation. Besides, clocking positions play an important role in the amplitude of the static pressure fluctuation for clocking case.