粘滞流体中两个尺度下的热对流的相互作用
Dripping convective instabilities develop under a cold thermal boundary layerwhen the local Rayleigh number exceeds a critical value Rac (Howard, 1966). Their86 Interaction of two scales of thermal convection in viscous fluidsinteraction with a shear flow is studied experimentally in a cavity heated from onevertical wall and cooled from above. Rayleigh numbers range between 104 and 108, andPrandtl numbers are greater than 1000. Within this parameter range, a hot horizontaljet develops under the cold boundary. The instabilities dripping from the latter aretherefore sheared by the flow and remain trapped in the jet, following a helicoidalpath with axis parallel to the jet flow. For high jet velocities compared to the drippingvelocity, 2D steady rolls prevail, while for low jet velocities, a 3D structure is observed.A phase diagram and scaling laws for the flow characteristics are determined.