A Secondary Flow Calculation Method for Single-Stage Axial Transonic Flow Compressors, Including Shock-Secondary Flow Interaction

A secondary flow calculation method is presented, which makes use of the meridional vorticity transport equation. Circumferential mean flow quantities are calculated using an inverse procedure. The method makes use of the mean kinetic energy integral equation and calculates simultaneously hub and tip secondary flow development. Emphasis is placed upon the use of a coherent two-zone model and particular care is taken to describe adequately the flow inside an unbounded (external), semi-bounded (annulus), and fully bounded (bladed) space. Along with the velocity field, the losses, the defect forces, and the corresponding additional work realized inside the viscous wall shear layer are calculated for stationary and rotating flow. An approximate model for the interaction of the viscous shear layers and the external flow is used, which takes into account the meridional and peripheral blockage. When shock waves are present in the external flow, an approximate interaction model is used, additionally, which calculates the static pressure field resulting from the interaction of the shock wave and the corresponding wall shear layer. The method has been applied to two single-stage transonic flow compressors and the results of the comparison between theory and experiment are presented and discussed.