Rayleigh-Flow T–s Diagram — Scramjet Thermal Choking (2D)

This is a 2D-native companion to the 3D scramjet-combustor simulator. Instead of animating particles through a rendered duct, it solves the identical Rayleigh-flow relations — T/T*, p/p*, and the stagnation-temperature ratio T0/T0* — and plots the flow's thermodynamic state directly on a temperature–entropy diagram, the classic textbook tool for analysing constant-area heat addition. The Rayleigh line's subsonic and supersonic branches meet at a single entropy-maximum point at Mach 1; because heat addition can only ever increase entropy, that geometric fact is exactly why a scramjet combustor thermally chokes once you add too much heat. A duct cross-section panel above shows the same pointwise temperature and Mach profile in physical space, so both the "why" (entropy) and the "what" (a decelerating, heating airstream) are visible at once.