Modelling the Mean Flow Through a Rotor in Axial Flight Including Vortex Ring Conditions

摘要

An engineering model for the mean flow through a rotor in descending flight, based on a vortex tube element representation of the wake, proposed by Wang~5 is re-examined and related to other theoretical approaches. The assumptions, on which the model is based and the properties of its vortex tube formulation are described and examined in the light of recent detailed theoretical calculations. This information is used to the expose important underlying physical issues.