Single-layer wire-mesh sensor to simultaneously measure the size and rise velocity of micro-to-millimeter sized bubbles in a gas-liquid two-phase flow

•Single layer wire mesh sensor (WMS) was developed to simultaneously measure the size and rise velocity of a bubble.•Suggested WMS was validated for a range of micro to millimeter sized bubbles under static and dynamic flow conditions•For the tested condition, the accuracy of measurement was found to be above 80 In this work, we propose a conductivity-based single-layer wire-mesh sensor (WMS) system to simultaneously measure the planar bubble distribution, equivalent diameter, and rise velocity of micro-to-millimeter sized bubbles in a gas-liquid two-phase flow. Compared with the conventionally available WMS system, the proposed system is capable of simultaneously measuring the bubble size and velocity using a single-layer sensor by establishing the correlation between the effective time taken for the bubble to pass through the sensor wires and its rise velocity, which is validated for micro-to-millimeter sized bubbles. Using this correlation, we have improved the recursive bubble identification method to develop a nonlinear model for bubble size, making it possible to selectively measure and distinguish between the bubbles in micro-to-millimeter scales (previous sensors were validated for large bubbles only). To accomplish this, we also investigated the differences in the dynamics of bubble-wire contact in detail. In a vertical upward bubbly flow, the present sensor was employed for a wide range of bubble sizes (200μm to 3.5 mm on average) and liquid velocity of 0−0.5 m/s; the measured data were in good agreement with those measured with a high-speed shadowgraphy. Finally, we discuss some issues of the proposed system, which requires a further attention.