Experimental characterisation of turbulent flow régime in the three-dimensional rotating-disk boundary layer

Fully developed turbulent flows are known to display some universal features when bounded by a solid wall. The flow due to a large disk rotating in otherwise still fluid undergoes transition from laminar to turbulent dynamics at a nondimensional radius R ' 500. The turbulent r'egime prevailing beyond this critical radius is unsual in several respects [4, 3, 2, 1]: it is sandwiched between a solid moving surface and the outer fluid at rest, and it develops in the radial direction while the main flow and shear components are in the azimuthal direction. The aim of the experimental work presented here is to characterise some features of this particular turbulent boundary layer.