The concept of fluid is a highly successful model, used to describe the dynamics of many-particle systems. In this book, the authors present new developments in hydrodynamics research. Topics discussed include numerical methods for multi-physical magnetohydrodynamics; hydrodynamic flows versus geodesic motions in contemporary astrophysics and cosmology; fractal hydrodynamics model and its implications; laws of bubble coalescence and modelling; nuclear hydrodynamics in heavy-ion collisions; and fluid flow in nanotubes.