LAMINAR-FLOW ROTOR FOR A RADIAL INFLOW TURBINE

The state of the boundary layers on the blade surfaces of the rotor of a radial inflow turbine has been investigated using surface-mounted h ot-film anemometers. The boundary layers are shown to be laminar or in termittently turbulent at the design flow condition, This is despite t he fact that the Reynolds number is relatively high and conventional t wo-dimensional numerical techniques predict transition at shout 20% su rface length, The boundary layer does not become fully turbulent becau se there is strong secondary flow and large acceleration of the flow c lose to the surface. Surface pressure distributions and an inviscid pr ediction method are used to assist in the explanation for the state of the boundary layers.