Effect of clocking on unsteady rotor blade loading in a low-speed axial compressor at design and off-design operating conditions

Abstract

This paper presents the results of stator clocking investigations at a design point and an operating point near the stability limit in a low-speed research compressor (LSRC).The unsteady flow field of the LSRC at several clocking configurations was investigated using a three-dimensional unsteady, viscous solver. The unsteady pressure on the rotor blades at midspan (MS) was measured using time-resolving piezoresistive miniature pressure transducers.The effect of clocking on the unsteady pressure fluctuation at MS on the rotor blades is discussed for different operating points.Based on the unsteady profile pressures, the blade pressure forces were calculated. The peakto-peak amplitudes of the unsteady blade pressure forces are presented and analysed for different clocking positions at both the design point and the operating point near the stability limit of the compressor.

Investigation of Flow Physics of Vane Clocking Effects on Rotor Resonant Response

“…Thus, the maximum response occurs when the maximum vortical gust coincides with the maximum downstream potential gust. This trend was also consistent with the trend observed by Jia et al [13] and Hsu and Wo [11] for the maximum response and pressure unsteadiness configurations.…”

“…The trailing edge of the center rotor blade also passes through the minimum downstream potential field at the same instant in time. Jia et al [13] and Hsu and Wo [11] both showed that the interaction of the maximum upstream vortical gust with the minimum downstream potential gust provided the minimum blade response and pressure unsteadiness.…”

“…Jia et al [13] modeled the first stage and a half (inlet guide vanerotor-stator) of the Dresden Low-Speed Research Compressor. Two clocking configurations corresponding to the minimum and maximum pressure unsteadiness acting on the embedded rotor blade's surface were investigated.…”

Igv Wake Effect in Centrifugal Compressor

“…Mailach et al 7 and Jia et al 8 found that the maximal pressure fluctuation reduces when the pressure fluctuation on the rotor blades induced by the IGV wake and the pressure fluctuations induced by the potential effect of the downstream stator blades are superimposed with approximately opposite signs in axial compressor. This relative motion leads to viscous and inviscid (potential) interaction between blade rows.…”

“…Mailach et al 7 and Jia et al 8 found that the maximal pressure fluctuation reduces when the pressure fluctuation on the rotor blades induced by the IGV wake and the pressure fluctuations induced by the potential effect of the downstream stator blades are superimposed with approximately opposite signs in axial compressor. Mailach et al 7 and Jia et al 8 found that the maximal pressure fluctuation reduces when the pressure fluctuation on the rotor blades induced by the IGV wake and the pressure fluctuations induced by the potential effect of the downstream stator blades are superimposed with approximately opposite signs in axial compressor.…”