Technical Note (draft) on the Conformation- and Concentration-Dependent Drag (C2D2) model for unentangled solutions of flexible polymers and numerical algorithms for rheological properties in steady and unsteady flows.

This document is a technical report intended to support understanding, use, and development of the codebase fro the Conformation & Concentration Dependent Drag (C2D2) model for viscoelastic stresses in unentangled polymer solutions. It is a working draft: notation, derivations, algorithmic details, and default numerical settings may evolve as the software matures. Portions of the model description and primary equations may later be adapted into one or more journal manuscripts; those manuscripts will cite a versioned, archived copy of this report and the corresponding code release.