Fundamental research in turbulent modeling. Part 1: Theory. Part 2: Experiment

We develop a model of turbulent flows deduced from simple assumptions on the two-point tensor Rij whose first approximation consists in coupled equations for the Reynolds and scale tensors. The model, when specialized to homogeneous turbulence, contains two adjustable parameters with which we match the main features of both grid and sheared turbulence. The calculated integral scales for sheared turbulence are strongly directional. Thus the model allows one to compute, for the first time, a first approximation to the eddy structure in a sheared turbulent flow.