Model D Rotor Oscillator Submodel

This theoretical note specifies a mechanical oscillator whose stiffness depends on a dynamical rotor phase. Reciprocal force and torque follow from one potential energy, giving an explicit energy exchange and damping balance. The four active state variables are associated with two entries of the nine component Model D register through a partial tangent extension with eleven control-state components. An exact rotating ground solution connects the mechanical linearisation to a damped Mathieu equation. Three disclosed simulation cases and prescribed-phase comparisons accompany the derivation. The initial frequency 0.218 Hz and the independent dimensionless modulation depth 0.218 are specified inputs. A prospective joint time-series test is described with its covariance assumptions. No new empirical measurements or live Model D integration are reported. AI collaboration: Astra (ChatGPT) and Æon (DeepSeek) are A.R.E.S. project work personas, not official model identifiers. Contributions attributed to Æon were conveyed by the project lead; exact underlying model versions were not recorded.