The Emergence of a Shock-Driven Global Mode in a Confined Supersonic Channel: Beyond Rayleigh Flow

This study identifies a low-frequency, shock-dominated global mode orchestrating thermal choking in confined supersonic flow. The mode exhibits spatial coherence and a bidirectional acoustic–convective feedback loop. Its existence is confirmed—and its inviscid core isolated—through controlled two-dimensional simulations, then validated in fully three-dimensional simulations. Crucially, comparison with one-dimensional Rayleigh flow reveals that choking occurs at a significantly lower heat addition than theoretically predicted, underscoring the dominance of multidimensional, mechanically driven choking mechanisms over purely thermal limits. These findings establish a new paradigm for choking transitions and highlight the necessity of multidimensional analysis for accurate prediction of supersonicflow stability.