Regenerative Cooling Channel Simulator (2D)

Every liquid rocket engine chamber wall faces combustion gas at 3,000+ kelvin for as long as the engine fires, and no metal survives direct contact with that for more than a fraction of a second. Regenerative cooling solves it by routing the propellant itself through a jacket of narrow channels wrapped around the nozzle before injection, so the coolant carries the heat away as fast as the flame delivers it. This 2D companion simulator marches the same real 1D steady-state thermal-resistance model along the nozzle contour — a Bartz-style hot-gas film coefficient that peaks at the throat, a thin conducting copper liner, and a Dittus–Boelter coolant film — but reads it out as a flat colored side-profile plus a live axial temperature chart instead of a 3D revolve, for whatever flow rate, chamber pressure and channel geometry you choose.