Fluid mechanics is a branch of physics with important applications in daily life. The calculation of flow drag on automobiles and high-speed trains benefits from theories in fluid mechanics. Moreover, many mechanical-based devices such as fluid pumps contribute to efficiency, and thus, to the modernization of society. This book highlights the experimental and theoretical aspects of wall-bounded flows to provide important information about related theories and applications. Boundary layer flow experimentation, modelling, and simulation must be considered together to obtain accurate calculations of parameters such as velocity profiles, pressure distribution, and turbulence level. This book is organized into three sections on the structure of the boundary layer, drag reduction initiatives using active control, and the verification and applications of flow mechanics. Chapters discuss the boundary layer type of different pressure gradients, Reynolds number, and speeds from 5 m/s to Mach 3. They also present the results of research on the active control technique for drag reduction initiatives to achieve efficient turbulence in high-speed applications, flow meter devices, and turbulence-generated noise mitigation initiatives.