Recent developments in CFD at ARA

Abstract

AbstractThe paper discusses recent work in the Theoretical Division at the Aircraft Research Association Limited (ARA) on the modelling of complex configurations, rotors, propulsion and viscous flows. The general features of the ARA multiblock system, which provides a grid generation and Euler flow solution capability for complex configurations, are discussed. Although very successful, the system has various limitations, in particular the tendency for the grid quality to depend on configuration complexity and type. A new multiblock system is being developed which allows regions of unstructured grid to be included, giving increased flexibility in dealing with complex geometries and other improvements. Work on rotors has included the development of a new Euler code for propellers, as a replacement for the code in current use. Improvements in flow solution offered by the new code are illustrated. In the propulsion field, the extension of a viscous-coupled Euler code for afterbody flows to a complete cowl unit is described briefly. The code is particularly relevant to the new generation of large civil turbofans. Work on Navier-Stokes methods for afterbody/nozzle flows is also discussed. Other work on viscous flows includes a 2-D investigation into viscous modelling with hybrid grids, and the further development of an established transonic flow aerofoil code.