Mode transition in bubbly Taylor-Couette flow measured by PTV

Effect of bubble’s arrangement on the viscous torque in bubbly Taylor-Couette flow

“…This conclusion is consistent with the observation of Yoshida et al 16 . Indeed, for the bubble sizes of 0.05 of the gap width, these authors observe an increase of the axial wavelength for a configuration capture up-down-outflow but, they related the augmentation of the axial wavelength to the capture of the bubbles inside the vortex down.…”

“…This phenomenon is due to a collective effect of the bubbles. It can lead to coalescence of a vortices pair, as observed by Yoshida et al 16 . This transient phenomenon, which is very localized in time, has not been analyzed in this work.…”

“…As defined previously, big symbols refer to large bubbles (0.12<d b /d<0.18) and small symbols refer to small bubbles (d b /d=0.05). Full disks refer to our study, triangles refer to Mehel 17 , blue empty square (C=0.45, H new =0.29) refers to Murai et al 7 and brown full square (C=3.87, H new =0.35) refers to Yoshida et al 16 (for geometry of 7,16 , W and λ were estimated from reference 14 ).…”

“…The statistical convergence is estimated for a confidence level of 95% in Table IV. Full disks refer to our study, triangles refer to Mehel 17 , blue empty square (C=0.47, H=0.24) refers to Murai et al 7 and brown full square (C=3.87, H=0.40) refers to Yoshida et al 16 (for geometry of 7,16 , W was estimated from reference 14 ). Figure 30 shows the phase diagram which summarizes the various types of bubbles arrangements as a function of parameters C and H. H is deduced from Fig.…”

“…For the weak turbulent flow and turbulent Taylor vortex flow, it was highlighted that bubbles have preferential accumulation regions, depending on the bubble size to the gap width ratio (d b /d) and the Reynolds number: either in the Taylor vortices or in the outflow region near the inner cylinder 7,[14][15][16] . For the turbulent flow, there is a preferential accumulation near the inner cylinder with a homogeneous axial distribution 12 .…”