Turbulent Flows is an up-to-date and comprehensive graduate text on this important topic in fluid dynamics. The book consists of two parts: Part I provides a general introduction to turbulent flows, how they behave, how they can be described quantitatively, and their fundamental physical processes. Part II is concerned with different approaches for modeling, or simulating, turbulent flows. Key appendices present the necessary mathematical techniques. While primarily intended for engineering graduate students, this book will also be valuable to students in applied mathematics, physics, oceanography and atmospheric sciences, as well as to researchers and practicing engineers.