Jean-Louis Marié

TL;DR: In this article, the sedimentation of a homogeneous dispersion of gas bubbles in water is studied, using double optical probe and hot-film anemometry, for high bubble Reynolds number (300-500), and high void fraction α (0-0.3).

TL;DR: In this paper, a single bubble is placed in a solid-body rotating flow of silicon oil, and from the measurement of its equilibrium position, lift and drag forces are determined, based on simulations over a wide range of bubble Reynolds numbers and bubble aspect ratios.

TL;DR: In this paper, the structure of an upward wall-bounded bubbly flow is investigated in the simple case of a turbulent boundary layer developing on a vertical flat plate, and it is shown that depending on their mean diameter, a significant fraction of the bubbles deflected towards the wall.

Abstract: The present study is devoted to the interaction between a swarm of bubbles and a turbulent field in a linear shear flow. The transversal and longitudinal evolutions of the void fraction and of the Reynolds stress tensor have been measured. When the air bubbles are blown uniformly into the shear, the void fraction profiles exhibit a strong gradient which can be explained by kinematical effects. No void migration has been observed. The behavior of the Reynolds tensor indicates that the nonisotropy induced by the mean velocity gradient decreases when the void fraction increases. A simple mechanism is proposed to interpret this fact, and a turbulence model based on one-point closures is compared to the experimental data.

TL;DR: In this article, the mean liquid velocity is shown experimentally to obey a modified logarithmic law of the wall in the presence of millimetric bubbles, and an expression for this modified law is derived by simple analytical considerations and non-dimensional scaling.