Experimental data from various sources for the frictional torque of a rotating disk in a stationary housing under the influence of a superimposed radial outflow were correlated.
Existing correlations were found to overpredict the frictional torque when the superimposed flow exceeds the pumped flow of the rotating disk. Therefore a new correlation is established for this case to improve the agreement with experimental results. Since the governing equation is an integral which can only be solved numerically the method is installed in a PC-based spread sheet programme for convenient use in the engineering practice.
For throughflow rates less or equal than the pumped flow of the rotating disk an existing correlation is modified to take account of the effect on the frictional torque of the axial distance between the disk and the stationary housing.