Condensate film flow on the surface of rotating cones

Abstract

A theoretical and experimental analysis has been made of condesating flow on the outer surface of 10o and 20o included angled, truncated, rotating cones. Experiments were carried out at steam pressures of 1.5, 2, 2.5, 3 and 4 oar absolute. The rotational speed range examined was such that it was possible to follow the progress from the stage at which ridge like waves was formed to that at which drops are thrown from the crests of the ridges. The peak film thickness was measured, employing an insulated pointer and micrometer technique, and a photographic record of the condensate surface profile was obtained. The latter record provided wavelength and ridge orientation measured with reference to the cone generator line. A theoretical equation is developed from the varier-stokes equations of motion with suitable boundary conditions for predicting the behaviour of the condensate film. Given basic film temperature difference and the physical properties of the condensate film then the wavelength, minimum film thickness and wave amplitude are determined for a known heat flux. The various configuration of the ridge like waves, as both steam pressure and rotational speed were varied, are presented and discussed. The points at which ridge like waves form and droops begin to be thrown from these ridges are examined and correlation made to predict these conditions. The effect of coriolis forces concerned with centrifugal force is examined to assortain the angle which the ridge makes with the core generator as ill progresses down the surface.