Compressor Surge & Stall — 2D Phase Portrait

An axial jet-engine compressor only pumps stably on the rising part of its pressure-flow characteristic — push it too far toward the stall line and the coupled dynamics between the rotor and the downstream plenum volume take over. This is a native 2D counterpart to the 3D Moore–Greitzer compressor simulator: the same real-time RK4 integration of the same two-state nonlinear ODE, but visualized the way a dynamical-systems analysis actually draws it — a phase portrait with nullclines and a vector field, an unrolled blade-cascade schematic, and a live strip-chart trace of φ(t) and ψ(t). Adjust the Greitzer B parameter and throttle opening, then fire an inlet distortion pulse to see whether the state point returns to its equilibrium, settles into a mild rotating-stall oscillation, or is swept into a deep-surge limit cycle with periodic flow reversal.