Design and feasibility demonstration of an integrated tube-mesh WMS–OFS sensor for co-located temperature and phase measurement in gas–liquid two-phase flow

Co-located measurement of temperature and phase distributions is essential for understanding thermal–hydraulic behavior in gas–liquid two-phase flows yet remains challenging because most existing sensing techniques provide either thermal or phase information with limited spatial correspondence. This study presents an integrated wire-mesh sensor (WMS)–optical fiber sensor (OFS) system for co-located multiparameter monitoring within a common sensing region. A modified tube-mesh WMS was developed to physically integrate a distributed optical fiber while preserving the measurement capabilities of both sensing techniques. Distributed temperature profiles obtained by optical frequency-domain reflectometry (OFDR) were reconstructed into cross-sectional temperature distributions and co-located with phase distribution measured by the WMS. Experiments were conducted under various gas injection and heating conditions to evaluate the proposed sensing approach. The reconstructed phase distributions clearly distinguished among different gas injection conditions, while the proportion of normalized conductivity values below 0.9 increased from 0.48% to 6.37% as the valve opening became larger, indicating enhanced gas dispersion and greater phase non-uniformity. Meanwhile, the integrated OFS captured localized temperature evolution induced by asymmetric heating. Representative time-coordinated measurements confirmed the spatial correspondence between reconstructed temperature and phase distributions, demonstrating the feasibility of co-located multiparameter monitoring. The proposed sensing framework provides a practical basis for real-time diagnostics and condition monitoring in multiphase thermal systems.