GAS-ABSORPTION AND SOLID DISSOLUTION IN A THIN LIQUID-FILM ON A ROTATING-DISK

Analytical and numerical solutions for mass transfer to a thin liquid film adjacent to a horizontal rotating disk are developed for the processes of gas absorption at the free surface and solid dissolution at the disk wall. The analytical approach was derived from a scaling analysis and presented solutions in closed form using confluent hypergeometric functions. The numerical approach solved the full three-dimensional transport equations. In the latter case, the location of the free surface was predicted by an iterative scheme and its irregular shape was preserved by employing a boundary-fitted curvilinear coordinate system for computation. Results are presented in non-dimensional form using Reynolds and Ekman numbers as parameters. It was found that for a given flow system, a significant enhancement of the absorption or dissolution rate can be achieved by increasing the angular velocity of the disk.