Secondary surge phenomenon of the compressor during surge recovery and its mechanism analysis

This paper explores the secondary surge during compressor surge recovery. Utilizing the test rig at Northwestern Polytechnical University, the surge is induced by tail cone adjustment. A secondary surge follows tail cone retraction post-initial surge. Signal changes are analyzed, and causes are expounded from energy and fluid dynamics. Experimental outcomes confirm the secondary surge is repeatable and observable under set conditions. Its frequency stabilizes at 4.83 Hz across consecutive events and rotor axes, being system-inherent. From energy, with enthalpy as a proxy, potential energy amasses as the compressor interacts with cavity potential shifts from tail cone changes. Exceeding kinetic supply instigates violent airflow oscillations. Peak pressure trends and simulations suggest surge likelihood at ∼3.33 × 105 J enthalpy. In fluid dynamics, post-initial surge, a stall state ensues. Tip clearance vortices from spillage and backflow expand, merge, and fill the passage. Their pre-secondary surge breakdown elevates pipeline pressure, causing gas reflux and surge recurrence. Conclusively, this research enhances compressor secondary surge comprehension, offering support for design optimization and anti-surge strategies.