Experimental study and flow visualization of gas entrainment in downward flow


Experimental study and flow visualization of gas entrainment in downward flow

Lopez, J. M.; Danciu, D. V.; Da Silva, M. J.; Hampel, U.; Mohan, R.

Downward bubble flow due to the gas entrainment under a falling film was experimentally investigated using the Wire-Mesh Sensor (WMS) and high speed video camera. The flow pattern was identified using the flow visualization analysis of the WMS. The flow visualization analysis was done in a 2-D (x, y), pseudo 2-D (x, t and y, t), and pseudo 3-D (x, y, t) dimension. The flow pattern observed during the experiments was bubble flow. Good agreement was found by comparing video images with the images obtained by the wire-mesh sensor. Additionally, gas void fraction time series and bubble size distribution are presented. Results show that images obtained from the high speed camera, WMS and experimental observations are in good agreement. Also, it is showed that different approaches for flow pattern recognition can be used. Moreover, results show the influence of the superficial liquid velocity on the gas void fraction and bubble size.

Keywords: air entrainment; flow visualization; flow pattern; wire-mesh sensor; gas void fraction

  • Contribution to proceedings
    7th International Conference on Multiphase Flow,ICMF 2010, 30.05.-04.06.2010, Tampa, Florida, USA

Permalink: https://www.hzdr.de/publications/Publ-13911
Publ.-Id: 13911