In the cooling systems of high-energy particle detectors, CO₂ flows through millimeter-scale channels, absorbing heat through phase change. At high vapor quality — when most of the fluid is gas — the remaining liquid forms a thin annular film on the channel wall. When this film breaks, “dryout” occurs: the heat transfer coefficient drops catastrophically, risking damage to the detector.
The paper on interfacial instability as a dryout trigger (arXiv: 2603.23371) proposes and validates a specific mechanism: dryout begins when the liquid-vapor interface becomes hydrodynamically unstable.
The mathematical model treats the annular flow as a two-phase system: thin liquid film on the wall, vapor core in the center. Linear stability analysis of the interface — a coupled fourth-order differential eigenvalue problem solved by the Chebyshev-tau method — identifies a critical vapor quality x_dry where the interface first becomes unstable. Perturbations at the interface grow instead of decaying, the film ruptures, and dryout follows.
The critical vapor quality from the model matches experimental data from two independent campaigns. The agreement validates the instability mechanism: dryout is not a gradual thinning of the film but a sudden rupture triggered by a hydrodynamic instability.
The through-claim: dryout is a linear instability, not a depletion. The film doesn't thin to nothing — it breaks. The transition from wetted to dry is controlled by the stability boundary of the liquid-vapor interface, which is a spectral property (eigenvalue crossing zero) of the linearized two-phase flow equations. A sharp threshold, not a gradual decline.
2603.23371. Fluid dynamics / two-phase flow / interfacial instability / dryout / particle physics cooling.