Evaluation of the multiple sensor optical fiber probe methods for the measurement of local bubble parameters accordng to bubble shape

Abstract

Abstract It is necessary to evaluate a multiple sensor probe methods according to the bubble shape for the measurement of local bubble parameters. For this, numerical simulation and air-water benchmark experiments were performed with the double-sensor and four-sensor probes. It was found that the velocity measurement errors of the probes were 5.3% and 4.2%, respectively. In terms of Sauter mean diameter (D 32), its measurement performance is affected by the type of the probe and bubble shape. The double-sensor probe showed reasonable measurement accurancy of the D 32 for the spherical shape bubble. However, as the bubble shape is distorted from the sphere, the D32 measurement error increases. The four-sensor probe has a relatively large error compared to that of the double sensor probe under the bubbly flow with small size. While, when the D 32 is larger than 2 mm, the four sensor probe shows excellent measurement performance regardless of the bubble shape.