The evaluation of turbulence models using tensor visualization techniques

A new method of representing a second order tensor, the tensor glyph, is used to present the Reynolds stresses found in turbulent flow. Various glyph types discussed in the literature are analyzed, and a glyph suitable for the Reynolds stress tensor is developed. This glyph is constructed so that the degree of anisotropy and the orientation of the principal directions are clearly presented. Using the glyph, the effectiveness of two turbulence model formulations of the Reynolds stress tensor, the Boussinesq approximation and the Algebraic Reynolds Stress Model (ARSM), are studied. Glyphs based upon these two formulations and experimentally measured Reynolds stresses are compared in two flow geometries: fully developed pipe flow and a tip leakage turbine cascade. The glyph representations are compared with traditional presentations of the Reynolds stress tensor to ascertain the strengths and weaknesses of both.