Active Suppression of Rotating Stall Inception with Distributed Jet Actuation

Abstract

An analytical and experimental investigation of the effectiveness of full-span distributed jet actuation for active suppression of long length-scale rotating stall inception is carried out. Detailed modeling and experimental verification highlight the important effects of mass addition, discrete injectors, and feedback dynamics, which may be overlooked in preliminary theoretical studies of active control with jet injection. A model of the compression system incorporating nonideal injection and feedback dynamics is verified with forced response measurements to predict the right trends in the movement of the critical pole associated with the stall precursor. Active control experiments with proportional feedback control show that the predicted stall precursors are suppressed to give a 5.5% range extension in compressor flow coefficient. In addition, results suggest that the proposed model could be used to design a more sophisticated controller to further improve performance while reducing actuator bandwidth requirements.

A Critical Review of Stall Control Techniques in Industrial Fans

“…The nonideal injection reduces the stall range's extension by about the same proportion of the effective pressure increase [56].…”

“…In an effort to minimise the power requirement, Vo et al [54] proposed the use of acoustic actuation and Corke and Post [55] proposed magnetic actuators. Interest remains high in air injection within the compressor community, with Vo [56] proposing a method to suppress rotating stall inception in multi-stage compressors around the compressor's full circumference, Figure 8. At the time of writing the use of air injection is limited to compressor applications as a consequence of the complexity and cost of the technology.…”

Tip injection as a means for rotating stall control in an axial flow fan

“…Modulated air injection gave better range extension than constant air injection for the same mean mass flow. Vo [26] carried out experimental and analytical investigations on distributed jet injection in a low-speed three-stage axial compressor. Twelve jet actuators were placed circumferentially uniform and pitched at 30 • before the first rotor.…”