Abstract
Sufficient knowledge of Reynolds stress is indispensable to understand the turbulence structure and to develop a turbulence model in gas-liquid two-phase bubbly flow. There is, however, little information on the Reynolds shear stress as well as radial and azimuthal turbulence intensities, whereas many researches have concerned on the axial turbulence intensities in a gas-liquid bubbly flow in a vertical pipe. In this study, we utilized a pipe made of fluoro carbon which has the same refractive index with water, and which enabled us to measure the two velocity components simultaneously using LDV in air-water two-phase bubbly flow in vertical pipes. The measured result indicated that all the components of Reynolds stress are affected by the presence of bubbles. Bubble-induced agitation of a liquid velocity field was particularly prominent under a laminar flow condition. Turbulence enhancement as well as suppression due to the presence of bubbles was observed.
