Where Total Pressure Dropped 1,080 Pa, Dissipation Was Zero — When the Bernoulli Constant Crosses Streamlines
·8 min read
Inside a spinning vortex core the total pressure falls 1,080 Pa while viscous dissipation stays exactly zero. A Rankine vortex marks where a head deficit stops meaning loss.
Two Faces of a Whirl — Free Vortex, Forced Vortex, and Helmholtz
·5 min read
A free vortex revolves with zero vorticity except at the center. The Rankine core spins at 2U/R and meets the 1/r tail smoothly at the core radius r = R.