Book excerpt: The 9th book from this successful conference series, on Computational & Experimental Methods in Multiphase & Complex Flow, presents the latest research in one of the most challenging, yet most universally applicable areas of technology. Multiphase flows are found in all areas of technology and the range of related problems of interest is vast, including astrophysics, biology, geophysics, atmospheric process, and many areas of engineering. Recently multiphase fluid dynamics have generated a great deal of attention, leading to many notable advances in experimental, analytical and numerical studies. It is perhaps, however, work on numerical solutions which is the most noticeable owing to the continuing improvements in computer software tools. Progress in numerical methods has permitted the solution of many practical problems, helping to improve our understanding of the physics involved. The presented papers illustrate the close interaction between numerical modellers and researchers working to gradually resolve the many outstanding issues in our understanding of multiphase flow. They cover such topics as: Multiphase flow simulation; Bubble and drop dynamics; Interface behaviour; Experimental measurements; Energy applications; Compressible flows; Flow in porous media; Turbulent flow; Image processing; Heat transfer; Atomization; Hydromagnetics; Plasma; Fluidised beds; Cavitation; Multiphase chemical reactions.