Turbulence modelling - Report of a Working Party

A review of turbulence modelling for aeronautical applications is presented, and recommendations for future progress in the field are suggested. External flow viscous turbulence models are based on boundary-layer development calculations matched with an inviscid-flow solution. Boundary layer calculations derived from the Bradshaw finite difference method require the use of a Reynolds-stress (RS) turbulence model. Internal flow models have lower Reynolds numbers than external; thus, the viscous layers are thicker. Turbulence models for various engine parts such as compressors (basic integral methods), combustion chambers (k-epsilon model), and jets and propulsion installation (k-epsilon model, but with better methods to account for the fluxes of heat and water) are presented. Short-term priority tasks include speeding up computer programs, applying methods to configurations of more complex geometry, and incorporating viscous effects into inviscid methods.