On the Flow of a Non-Newtonian Liquid on a Rotating Disk

The equations describing the flow of a power-law non-Newtonian fluid on a rotating disk have been solved in general form. This makes it possible to calculate how the shape of an initial surface contour will vary with time and to investigate the possibility of producing uniform films by applying the materials to a rapidly spinning disk. It is shown that the latter process, which has potential industrial applications, has a much better chance of succeeding if the fluid is Newtonian than if it is not, in the sense that whereas for a Newtonian substance centrifugation will smooth out irregularities in the surface contour, for a non-Newtonian fluid even an initially uniform film thickness will be deformed by rotating the plate.