Based on a common concept, an introduction to fluid and thermodynamics is provided for students of physics and engineering. In hydrodynamics, hydrostatics, the hydrodynamics of ideal and viscous fluids, as well as laminar and turbulent pipe flows are covered, while thermodynamics addresses the first and second laws. Gas dynamics includes acoustics, stationary isentropic flow theory, and shock theory, thereby intertwining fluid and thermodynamics. As a special feature, a chapter on dimensional analysis and model theory is included, which opens up the exploration of technical issues and highlights environmentally relevant problems.