This book offers to students, engineers, CFD modelers, and scientists a detailed synthetic presentation of turbulence physics and modeling with the possibility to find a quick route through the jungle of publications and models. Chapters 1 to 4 show that turbulence models may be derived and analyzed in a physically sound manner with their potential merits and drawbacks. Chapters 5 and 6 review the physics of (inhomogenous) turbulent flows starting from the most simple flow cases and adding more and more complexity. The status and uncertainties of available experimental data and the practical performance of currently available turbulent models are discussed.