Assessment of the Basic Metrological Properties of an Optical Tomograph at the Gas-Bubble Measurement

Mariusz R. Rzasa1, Boleslaw Dobrowolski2

Technical University of Opole, 45-233 Opole, ul.Mikolajczyka 5, Poland

1mrz@po.opole.pl, 2bolo@po.opole.pl

ABSTRACT

The paper includes the structure of a prototype optical tomograph for detection and measurement of shapes of the gas bubbles moving into a liquid. In the applied method of measurements, the column is exposured by a homogeneous light beam and next the ray is detected with use of optical wave-guided detectors. Spatial reconstruction of the bubble shapes is done on the basis of the signals coming from two perpendicular systems of detectors. The bubble shape is approximated by the ellipsoid with suitably determined semi-axes and with use of the genetic algorithms.

Influence of structure and dynamics of the measuring path on errors in representation of gas-bubble shapes and velocities has been analysed. The paper also contains the results of the tomograph tests.

Keywords optical computer tomography, gas-liquid flows, measuring errors