Reconstructing Experimental Data from Video Records for Film over a Spinning Disk

New non-invasive method to obtain quantitative information about wave regimes from recorded videos has been developed and utilized on numerous video sequences. The videos were recorded using an experimental set-up with a spinning disk whose rotational speed as well as flow rate of water pouring onto a disk were controlled. Particular attention was paid to stationary spiral waves observed on the film surface at relatively large flow rates. Analysis of numerous videos allowed us to conclude that the observed spiral waves are approximated by the Archimedean spirals whose coefficients depend on the Eckman number. Experimental results are in a good agreement with numerical results obtained from a new evolution model describing film flow over a spinning disk.