Pipeline simulation
1 inlet -> 1 outlet (Darcy ΔP over a pipe)
Governing equations
The exact equations the solver works for a pipeline — the same math shown in the app's "Theory" panel, not a black box.
Parameters
diameter [m], length [m]; optional angle_deg, roughness [m], viscosity [Pa·s]. Also usable as a mode='pressure_driven' resistance element (no extra params needed — the same Darcy-Weisbach law is inverted implicitly by that mode's Newton solve). polymer_melt [bool, default False]: when the inlet carries a polymerization reactor's polymer_mwd, derive a real non-Newtonian apparent viscosity instead of the constant 'viscosity' param — optional eta_ref_pa_s + mw_ref_kg_mol [reference melt-viscosity datapoint], mw_scaling_exponent [default 3.4], n [Carreau power-law index, default 0.4], lambda_relax_s [default 1.0], eta_inf_pa_s [default 0], temperature_ref + activation_energy_j_mol [optional Arrhenius T-shift]