solprop.translate.walls

The coupled flows of a capillary’s mode set: the coherent wall and the taper.

A coherent wall block (scalar or vector, on a constant or a varying guide) and the taper coupling of a multimode capillary keep a shared scalar carrier in the cumulative diagonal Phi and put the modal part of the flow in linear.coupled_flow (docs/dev/kernel-contract.md section 3), with the generators, connections and passivity checks they are built from.