Nonintrusive Dynamic Pressure Monitoring of Sloshing Liquid Using a Hierarchically Microstructured Flexible Sensor.

Area of Science:

• Fluid Dynamics
• Materials Science
• Sensor Technology

Background:

• Dynamic pressure monitoring in sloshing liquids is crucial for safety in storage, transport, and aerospace.
• Conventional rigid pressure transducers have limitations, including flow disturbance and incompatibility with curved surfaces.
• Uncontrolled sloshing can lead to structural loads, instability, and containment failure.

Purpose of the Study:

• To evaluate a hierarchically microstructured flexible pressure sensor (FlexiHMS) for monitoring slosh-induced wall pressures.
• To benchmark the performance of FlexiHMS against a commercial piezoelectric (PZT) sensor.
• To investigate the potential of flexible sensors for nonintrusive pressure monitoring in fluid-structure interaction systems.

Main Methods:

• Controlled sloshing experiments were performed in a rectangular tank with varying fill volumes (22%, 30%, 70%).
• Base excitation was applied from 0.8 to 1.2 times the first-mode natural frequency.
• FlexiHMS performance was compared to a commercial PZT sensor, with data analyzed using fast Fourier transforms and boxplots.

Main Results:

• FlexiHMS accurately captured dynamic pressures from 0.3-127 Pa and showed resonant amplification behavior.
• Nonlinear pressure characteristics, dispersion, and intermittency were observed near resonance.
• FlexiHMS demonstrated superior performance, maintaining measurable responses where PZT sensors diminished, especially at higher fill volumes.

Conclusions:

• The hierarchically microstructured flexible pressure sensor (FlexiHMS) is a viable alternative to conventional rigid sensors.
• FlexiHMS offers conformal, nonintrusive dynamic pressure monitoring, particularly in fluid-structure interaction scenarios.
• This technology is suitable for applications where traditional sensor mounting is impractical, such as on curved or flexible tank surfaces.