Instabilities between rotating and stationary parallel disks with suction

Abstract

From visualizations, we study the patterns’ formation of the flow in a stationary cylinder driven by a rotating bottom disk when central suction is applied. That creates an annular axial jet at the cavity periphery which destabilizes and gives rise to instability patterns. We distinguish two types of instability patterns and study more particularly the one which takes place in the boundary layer of the cylindrical wall.

Crossflow instability in rotor-stator flows with axial inward throughflow

“…Moreover we showed that the mean radial and tangential velocity profiles exhibit inflection points, which is a characteristic of this type of instability. We have also shown that the SRJ2 spiral rolls are comparable to the structures denoted 2 by Rémy et al (2005), which are a crossflow instability attached to the axial jet: spirals with a small wavelength and a large wavenumber. The only discrepancy remains the inclination angle, which is much larger in our experiment, up to 72 • , which could be due to the radial gap.…”

“…The flow is then mainly governed by the rotation. For high values of the axial velocity V z , the flow is governed by the throughflow and the SRJ2 patterns are comparable to the structures denoted 2 by Rémy (2004) and Rémy et al (2005). The main characteristics of structures 2 are a high wavenumber 40 6 k * 6 70 and a weak frequency N 6 3.5 Hz.…”

“…We recall also that they are located at the periphery of the rotating disk. Rémy et al (2005) proved that this instability is a crossflow instability: an azimuthal flow due to the rotation is in competition with a radial flow due to the inward throughflow and the radial profiles of the axial and azimuthal velocities exhibit inflection points. That is also the case for the SRJ2 spirals.…”

“…To our knowledge, the only study concerning the instabilities occurring in a rotorstator cavity when a centripetal throughflow is superimposed has been performed recently by Rémy (2004) using stereoscopic particle image velocimetry (PIV) and Rémy, Gauthier & Buisine (2005) using a tomography technique. They have studied the SR1 spiral rolls in a rotor-stator system with suction for large aspect ratios G > 0.088.…”

Influence of rotor–stator component partition structure on the aerodynamic performance of centrifugal compressors

“…These subtle flow phenomena interact with the main flow and can threaten the efficiency and stable operation of centrifugal compressors (Qin, Sun, Wang, Ju, & Zhang, 2016). In earlier studies, the rotor and stationary components were simplified to a 'rotating stationary disk' problem to examine the flow structure in detail (Remy, Gauthier, & Buisine, 2005;Remy & Buisine, 2006;Jiao & Fu, 2016). However, in recent years, studies have focused on investigating the actual structure.…”