The Thickness of Aviscous Liquid Film on a Rotating Disk

Various theoretical solutions including the author''s for the thickness of a viscous liquid film on a rotating disk are presented in terms of two dimensionless parameters and are compared with experimental results. The film thickness on the disk was measured by a micrometer which is movable with a needle used as a surface detector. The numerical solution of the equations as simplified by von Karman''s method and Bruin''s solution agree well with the experimental results in a wide range of operating conditions. Polynomial approximation with orders up to fourth and fifth degree is usable to predict the film thickness.