Acoustic Diagnostics of Two-Phase Flow

Why it matters

Two-phase flows (boiling and condensation) move large amounts of heat, but they can shift suddenly between regimes. The most dangerous shift is critical heat flux (CHF), where a vapor blanket insulates the surface and its temperature rises very quickly. Most industrial systems are opaque, so the high-speed imaging used in the lab isn’t available in the field. Sound is: bubble growth, collapse, and slug motion each produce a characteristic acoustic signature.

Our approach

• Synchronized acoustic and high-speed optical measurements of pool boiling and flow condensation
• Signal processing and data-driven feature extraction that link acoustic signatures to specific interfacial events and flow regimes
• Using these signatures as non-intrusive, low-cost sensors for real-time monitoring and early warning

Selected outcomes

• Slug Flow Condensation Identification with Acoustic Signatures, International Journal of Heat and Mass Transfer (2026)
• “Acoustic Signatures of Boiling Critical Heat Flux and Interfacial Instabilities”, APS-DFD (2023)
• “Acoustic Insights into Flow Condensation Mechanisms”, Gordon Research Conference (2025)

Broader relevance

Non-intrusive, real-time sensing of two-phase flow state is valuable wherever liquid cooling or phase change takes place inside closed hardware. Examples include power electronics, data center cooling, process equipment, and aerospace thermal systems.