What is real vs modelled
Real, sourced: thrust, chamber pressure, specific impulse, mixture ratio, dry mass and dimensions are published SpaceX / reference figures for the sea-level engines. Modelled: the geometry is a schematic cutaway, not CAD. Throttle scales thrust, pressure and flow linearly. Altitude uses an exponential atmosphere; nozzle exit pressure, pump power and Merlin's overboard fraction are order-of-magnitude teaching estimates. The plume, Mach diamonds and flow animation are stylised for readability.