Controlling turbulent bubbly flow through a jet array

Bubble deformation strongly affects its lateral migration in a shear flow, including both the mean or turbulent shear. But the classical experiments studying this problem in a pipe flow cannot disentangle these two effects. To control the profile of the mean flow and turbulence in a water tunnel, we modified our vertical tunnel, V-ONSET, to move away from the canonical homogeneous and isotropic conditions. The tunnel is equipped with a unique jet array with 88 independently controlled nozzles, each of which is connected through a dedicated adjustable valve and solenoid valve to control the flow rate and its on-off state. With this large degree of controllability, we aim to generate a well-prescribed level of shear in the test section. The turbulent shear flow is then inspected in detail by using our in-house 3D Lagrangian particle tracking system, and the results will also be presented in this talk.