COMPARISON BETWEEN FLUORESCENT CLASSIC 2D PIV AND FLUORESCENT STEREO-PIV MEASUREMENTS OF THE LIQUID PHASE VELOCITY IN A BUBBLE COLUMN

Rodrigo de Lima Amaral¹; Diana Isabel Sánchez Forero¹; Guilherme José de Castilho¹; Sávio Souza Venâncio Vianna¹; Milton Mori¹

¹ UNICAMP

doi:10.20906/CPS/COB-2015-1921

Resumo

The Fluid dynamic analysis in bubble column reactors is important in heat and mass transfer and chemical reaction rate. Particle Image Velocimetry (PIV) is a non-intrusive technique used to determine the 2D (Classic 2D PIV) or 3D (Tomographic PIV) velocity field. Using the Stereoscopic -PIV (Stereo-PIV) it is possible to determine the third component of velocity by two cameras with different projections, resulting in a 3C-2D (two dimensional, three-component) field. The loss of correlation due to the out-of-plane motion of pairs of particle images, which is common in PIV applications, is reduced using the Stereo-PIV system. A problem encountered in Stereo-PIV applications is the restricted optical access in some facilities. Fluorescent tracer particles and a high-pass filter on the camera are used in Fluorescent PIV systems to determine the liquid phase velocity in bubble columns, so that the bubbles are not recorded in multiphase flow. This work aims to evaluate the quality of the Fluorescent Classic 2D PIV and Fluorescent Stereo-PIV measurements of the liquid phase velocity in a bubble column section. The Fluorescent Classic 2D PIV and Fluorescent Stereo-PIV images were processed using standard cross-correlation and ensemble correlation in order to compare the measurement quality. The cross-correlation coefficient, Signal-to-Noise Ratio (SNR) and PIV uncertainty estimated using correlation statistics were also analyzed as quality indicators.

Palavras-chave: Fluorescent Stereo-PIV; Fluorescent PIV; Correlation; Two-Phase Flow; PIV uncertainty