Enhanced Detection of Individual Gas Bubbles in Multiphase Flow by Distributed Acoustic Sensing

Distributed Acoustic Sensing (DAS) is a promising technology for monitoring multiphase flows, yet its application to low gas fraction regimes, such as bubbly flows, remains challenging. This study explores the detection of millimeter-scale gas bubbles in a chemical reactor using tailored fiber wrap configurations and advanced multi-step filtering. Experimental results demonstrate that the proposed approach reliably tracks bubble rise dynamics, with velocities matching theoretical predictions. The gauge length is identified as a key parameter for optimizing signal quality. These results establish a basis for broader deployment of DAS in the (bio)chemical industry.