EROS - a common European Euler code for the analysis of the helicopter rotor flowfield

The helicopter rotor flowfield is one of the most complex and challenging p roblems in theoretical aerodynamics, Its accurate analysis is essential for the design of rotors with increased performance, reduced vibratory loads a nd more environmentally friendly acoustic signatures. European rotorcraft m anufacturers have an urgent requirement for a rotor aerodynamic prediction tool to be used within the design office on a routine basis and which is ca pable of capturing rotational phenomena, such as blade tip and wake vortice s, and correctly predict the unsteady blade pressures over a range of diffe rent flight conditions. The EROS project addresses this requirement by deve loping a common European rotor aerodynamic system capable of analysing the inviscid rotor flow environment by solving the three-dimensional Euler equa tions, The method is based on a proven-technology time-accurate Euler formu lation on overlapping structured grids (Chimera method), The grid generator provides an all-in-one capability for grid generation guiding the user fro m the generation of individual component grids to the Chimera domain decomp osition through an interactive process which has embedded visualisation and animation capabilities. The cell-centered finite-volume solver adopts a du al-time implicit scheme on deforming grids. Non-conservative interpolation is used to transfer information across grid overlap regions. This article p resents the main components of the system and reviews its capabilities thro ugh a number of applications. (C) 2000 Elsevier Science Ltd, All rights res erved.