Mesh generation: Art or science?

Mesh generation has evolved to the point where highly complicated domains can be covered by a variety of mesh types including hexahedral, tetrahedral and overset meshes. The application of these methods to computational aerodynamics has become a routine exercise and numerical predictions over complete aircraft now complement experimental results obtained from wind tunnels. This paper surveys the main developments that have taken place and traces the evolution of mesh generation over the last 35 years. This is followed by an assessement of the accuracy of Navier Stokes codes that are currently in use for predicting the drag of an aircraft at transonic cruise. The relationship between solution accuracy, mesh size and mesh type is examined in some detail and the implications for further research are discussed.