Specificity of laminar-turbulent transition in upward monodispersed microbubbly flow

Results of experimental investigation of the wall shear stress in the upward monodispersed bubbly flow in a vertical tube are presented. The bubble generator based on the flow focusing technique has been developed for monodispersed submillimeter bubbles production. The results of investigation prove that submillimeter bubbles significantly increase the flow mass transfer with the wall. Some peculiarities of the inherent liquid turbulence interaction with pseudoturbulence induced by submillimeter bubbles in transitional flow regime have been detected.