Hydrogen peroxide assisted lean operability extension and front coherence in a nitrogen-diluted hydrogen–oxygen rotating detonation engine

This study examines whether hydrogen peroxide (H 2 O 2 ) addition extends lean rotating-detonation operation while preserving pressure-front coherence. Two-dimensional transient reacting-flow simulations were performed for 38 lean conditions in a premixed nitrogen-diluted H 2 –O 2 rotating detonation engine, spanning equivalence ratios of 0.550–0.700 with case-dependent H 2 O 2 addition. Propagated states were assessed using wave velocity relative to the case-specific Chapman–Jouguet (CJ) value, dominant high-pressure-component fraction, front-disruption events, upper-tail pressure intensity relative to the case-specific Zel’dovich–von Neumann–Döring (ZND) pressure, mean OH mass fraction, and pressure–OH spatial coupling. Within the sampled matrix, H 2 O 2 addition extended observed lean propagation from ϕ = 0.700 to ϕ = 0.560 . All propagated cases retained detonation-like velocities, with U x / U CJ = 0.892 –0.930, but velocity alone did not distinguish coherent-front from transverse-wave or front-disrupted propagation. Coherent-front cases exhibited a more dominant pressure structure, fewer disruption events, near-reference upper-tail pressure intensity, and near-unity pressure–OH coupling. Mean OH increased monotonically with H 2 O 2 addition within each equivalence-ratio series, whereas pressure–OH coupling provided the clearest separation among the diagnostics evaluated within this two-dimensional matrix. Sensitised lean operability should therefore be assessed using coupled propagation, pressure-topology, and OH-field diagnostics rather than wave survival or velocity alone.