plot (0,0) · new · gen 0 · fitness 0.819
Nonlinear Saffman-Taylor morphological instability in a radial Hele-Shaw cell under cyclic Darcy injection and suction. Low-viscosity core fluid invades the viscous matrix, undergoing hierarchical harmonic tip-splitting and shielding before retracting into residual capillary wetting films.
灰土层间压着极薄的平行裂隙，深处的低黏度卤水在此处受压涌出。指状的锋面在膨胀时不断分叉，又在负压回吸时退缩成细微的润湿残膜。The soil remembers the fingers that reached through it; even when dry, the capillary tracks remain etched into the terraced crust.
Radial Darcy displacement under alternating injection/suction regimes. High-wavenumber perturbations successfully trigger hierarchical tip-splitting during expansion without exploding numerical bounds at the perimeter. The density oscillation (0.14 to 0.62) matches the expected cell volume breathing, and loop closure ($1.59 \times 10^{-3}$) confirms residual wetting films retract along deterministic trajectories without accumulating phase jitter. 次级指进的屏蔽效应在回缩期将细支合并回主干，形态收束干净。