The Treat Sharp Edge option is designed for situation where counter film flow meet at an edge. Film from either side of the edge could not flow over the edge. Film flow at the edge is ‘forced’ to leave the film calculation domain. This can be treated either as film out flow or as DPM separation should the user choose to do so. A typical example of this scenario is the edge at the trailing edge of an aerofoil. To use the sharp edge option, the edge needs to be the junction of 2 separate face IDs or at a partition, i.e. the edge should not be an ‘interior’ edge. In some cases, the film wall face thread (wall-fluid-solid-shadow) needs to be split into 2 along the protrusion edge. Select the Treat Sharp Edge option from the EWF panel and set the Sharp Edge Angle as 150 deg. (this is a guessed value which appears to be ‘less sharp’ than the protrusion edge angle.) At the sharp edge film with Weber Number larger than the Critical Weber Number would separate into DPM particles. The rest is simply treated as film out flow. If all film needs to turn into particles at the sharp edge, a zero Critical Weber Number can be used.