Capillary Phase-Locking in Solar Desalination
Solar evaporation is admissible as thermally limited only if interfacial capillary modes remain incoherent under steady energy input. If phase-locking amplifies evaporation at equal energy, then the governing constraint is coupling—not heat.
Evaporation is not purely thermal. It is governed by the degree of phase coherence at the interface. If energy is delivered incoherently, the system underperforms its physical potential.
Evaporation scales with steady thermal input
Solar desalination systems assume evaporation rate is governed by steady-state thermal gradients and mean energy input.
Capillary modes remain incoherent under steady forcing
Thin water films support capillary wave modes, but under steady illumination these remain weak, incoherent, and unexploited.
The interface is treated as passive, rather than a dynamically excitable system.
Phase-locking amplifies interfacial energy transfer
When energy input is modulated at the natural resonance frequency of capillary modes, oscillations phase-lock and amplify.
This increases curvature, pressure gradients, and effective vapor-pressure differential—raising evaporation without increasing total energy input.
Degree of phase coherence at the interface
The governing variable is not temperature, but coherence between energy input and capillary resonance.
- Incoherent input → suppressed evaporation
- Partial coupling → moderate gain
- Phase-locked → amplified flux
Capillary Resonance Coupling Coefficient (CRCC)
CRCC quantifies the increase in capillary oscillation amplitude when input energy matches the natural resonance frequency.
It directly correlates with evaporation enhancement and serves as a measurable proxy for interfacial coupling efficiency.
Steady vs phase-modulated illumination
- Apply steady illumination → measure baseline evaporation
- Apply modulated illumination at resonance frequency
- Maintain identical mean energy input
- Compare evaporation rate and oscillation amplitude
What breaks the assumption
Pass: No increase in evaporation under phase-modulated input.
Fail: Measurable increase in evaporation and CRCC at equal energy input.
Evaporation is coupling-limited, not heat-limited
If phase-locking increases evaporation, then thermal models alone are incomplete. Interface dynamics become the primary design axis.
A system is not limited by energy—it is limited by how energy couples.
If the interface cannot synchronize with incoming energy, potential work remains unextracted regardless of input magnitude.