EXPERIMENTS ON TURBULENT-FLOW DUE TO AN ENCLOSED ROTATING-DISK

An experimental study is undertaken on the turbulent flow due to an enclosed rotating disk. Measurements of the mean velocity distributions and all six components of Reynolds stress are made for the two boundary layers developed on the rotating disk (rotor) and the stationary end wall (stator). It is revealed that the velocity distributions in the respective boundary layers show a similarity at constant local Reynolds number Re(L). A log-law region where the circumferential velocity profile follows the logarithmic law for the flat-plate boundary layer is observed at high Re(L) values. All the components of Reynolds stress normalized by the friction velocity are larger inside the stator-side boundary layer than in the rotor-side boundary layer. The directions of the shear stress vectors are found not to coincide with the directions of the velocity gradient vectors.